I may regret this post and I'll let you know. I just got back from a Les Schwab tire center to have my almost 7 year-old Toyo Open Country H/T tires checked out by the service manager. After looking at all the tires (he did not remove them), he found no checking or cracking and said that the tires were in good shape. He told me that if they were his tires, he would keep driving on them and consider replacing them between 9-10 years old.
Note that I only have about 12,000 miles on the tires and I don't plan to be driving in overly hot weather before I get them changed. He told me that keeping weight off the tires using my levelers helps stem the degradation of the sidewalls.
Your mileage literally may vary!
Mike S.
Yikes.....way too many posts by others that have experienced major problems after receiving the same "guidance"......though mine look great and I'm in the exact same boat as you (7 years, low mileage) I elected to install new tires...actually have an appointment tomorrow morning....good luck.....
Bill
"Note that I only have about 12,000 miles on the tires..."
In my estimation mileage may be a least indicator!
Back a few years I had a long discussion with Chuck The Tire Man. It was his contention that six years was about the maximum life for your average tire, admitting that some brands will not break down that early, like the Goodyear G947s that he was installing on my LD as the conversation took place. He said I would probably get 8-10 years from them. Being once bitten (by Michelins) and twice shy I changed those out at 7 years. I'm now on the second set.
My (Michelin) failure occurred in mild weather on the Hwy between Willits and Fort Bragg. If you've never heard a tire explode believe me, it will get your attention! There was only very mild checking to be seen on the other tires in that set. :o :-[
[/quote] My (Michelin) failure occurred in mild weather on the Hwy between Willits and Fort Bragg. If you've never heard a tire explode believe me, it will get your attention!
[/quote]
What tire was it? Was it the rear passenger-side inside dual by any chance?
BTW, Goodyear's warranty times out after six years, the same as Michelin.
https://www.goodyear.com/content/dam/gy-com/documents/Goodyear_Tires_Limited_Warranty.pdf
Tires age no matter how much or little they are used. Running tires ten to twelve years is asking for problems. IMO
Wish the Goodyears were the absolute cure for blowout but I have heard of blowouts with all brands of RV tires, including Goodyears.
The rear, passenger-side, inside dual tire is most likely to blow, due to being exposed to the heat of the exhaust .
After having the inside, rear tire blow , I installed heat shields and now rotate the rear tires periodically, done as a blowout preventative.
Exhaust heat shields | Flickr (https://www.flickr.com/photos/lwade/sets/72157693074909430/)
Larry
I remember Chuck Carvitto telling me that a big part of his business was replacing blown tires as he was located out in the hot desert.
Larry, I'm sure you have covered this before, but how do you rotate your rear tires? Outside to outside and inside to inside?
Thanks,
Mike S.
how do you rotate your rear tires? Outside to outside and inside to inside?
With the extended stems, you are forced to an outside to outside and inside to inside rotation.
Larry
"Was it the rear passenger-side inside dual by any chance?"
Negatron Good Buddy, it was the passenger side 'out-side'! Fortunately the shreds did not do any damage. ::)
"Tires age no matter how much or little they are used."
----
Yes. RV tires are subject to significant heat and stresses, particularly to the sidewalls, and the stresses are exacerbated several times over if the tires are overloaded and/or run underinflated for the weight of the rig. Age, exposure to UV and air pollutants, and using "tire protectant" products containing petroleum distillates, e.g., Armor All, speed the deterioration.
Opinions vary, of course, but I've found that following a 5-year replacement schedule, buying top-quality tires (in my case, Michelin Defenders), and accepting only the freshest, date-matched tires, has worked well to help avoid tire issues over many years. My TK runs well under the 14050 lb. gvwr, and the tires are inflated per its weight. (A clever friend with "tin snips" crafted lovely heat shields to provide extra protection against excessive heat reaching the inside duals. ;) )
Going down the road on "old" or marginally "old" tires would be very unsettling, and I sure would not even think about heading off on a road trip with tires of questionable age.
YMMV, as ever.
Chuck Carvitto gave some questionable advice over the years. Avoiding Michelin tires (as I recall, he didn't sell that brand), expecting to get ten years from a set of Goodyears on a heavy motorhome, and dynamic balancing not being important (of course, he didn't have the equipment to do it) come to mind.
As for Mike's question, one needs to balance the cost of a set of tires (not cheap) against the cost of repairs after a blowout. It isn't just the risk of loss of control. Rotating at highway speeds, those big, heavy tires pack quite a payload of kinetic energy. When one comes apart, the fragments can tear off your dump valves and plumbing, break your holding tanks, and even rip right through the floor to damage inside cabinets. Those are expensive things to repair.
Once in the past I got careless and drove on tires with checked sidewalls. Joan pointed them out, and I replaced them. I've been more careful since then.
As an example of how careless some RV owners can be, my brother purchased a 2010 Jayco Greyhawk a couple of years ago.
He purchased the rig from a dealer in Arizona. He lives in Fruita, CO. Proudly he texted me of his purchase. My first question, “How are the tires”? He sent me pictures.
Checking, cracking, no matching DOT dates. Some tires nine years old others six, one new. All the tires had been slathered with tire black and from a distance they appeared in good shape. Up close...what a hot mess. My advice to him, “Get the dealer to put on new tires or go straight to a tire shop”. He drove the rig home on those ratty messes. Many hundreds of miles on tires that could blow all at once. He made it home safely. I was a nervous wreck.
The following week he had all seven tires replaced and installed a TPMS.
Our Lazy Daze is approaching year four pushing 17,000 + miles. New tires are on the quickly approaching horizon. Budget for the future and enjoy your tomorrows.
Kent
What is checking on a tire? Cracking I know but I have not heard of checking.
Jane
"What is checking on a tire? "
Checking is the early stage of cracking, tiny little hairline blemishes that when they grow up will become cracks. It takes a practiced eye to see them, along with good lighting but once they start there's no going back. :o
"What is checking on a tire? "
Checking is the early stage of cracking, tiny little hairline blemishes that when they grow up will become cracks. It takes a practiced eye to see them, along with good lighting but once they start there's no going back. :o
If you google 'tire cracking and checking picture' you will find examples.
I hope things have changed but in the late 60's - early 70's in the South Coast Air Basin they measured ozone levels
by how long it took a finely calibrated rubber band to rot and snap. That comes to mind when thinking of tires and pollution.
Joel
It was my understanding that “checking” was the appearance of small cracks in the sidewalks of a tire. “Checking” would be signs of an ageing tire and a warning to get new tires.
https://youtu.be/qOdjBYnP6_U
One dictionary definition of checking is “to crack or split usually in small checks”...”painted surfaces may check with age”. Paint checking can often be seen in car paint.
Kent
Oh gosh, I love posts like this since have a very special interest in tires. If you wish to know more, just ask :)
The worst possible conditions for tires happen to be high speed with a heavy load in warm climates. Sounds like a typical RV day to me. I am not aware of any type of visual inspection method that would provide the amount of degradation taking place in belt wedge or skim rubber - these internal components have much to do with the probability of a belt separation taking place. And when it comes to belt issues vehicle load is the number one metric to consider.
For an RV application I would not trust a tire over five years old no matter what it looks like on the outside or how many miles it has been in service.
Would not a decent TPMS help avoid these tire blowouts? Usually there is a loss of pressure and certainly an increase in temperature first. Have any of these blowouts occurred with TPMS installed and was there any warning in advance?
Here is Continental Tires take on tire age:
"Continental is not aware of any technical data to support the removal of service for tires past a specific age. But the same principle applies to the tires of your vehicle as it does for any other part of your car – age matters.
Together with other members of the tire and automotive industries, Continental advises that all tires (including spare tires) made more than ten years ago should be removed from service and replaced with new tires."
For the full statement, including caveats: Things to know about the age of your tires | Continental tires (https://www.continental-tires.com/car/tire-knowledge/tire-damage-age-repair/replacing-tires)
Personally, I drive my RV enough that they wear out before 10 years, typically at 5-7 years, so I don't have the dilemma to deal with. I think I would be comfortable using 8 year old tires, if they are: from a major manufacture, visually in very good condition, have no history of major impacts, and I will be driving in less than 90 degree ambients. Note that I cruise at 60 mph.
Ah tires, coffee and black tanks always good for a long thread .....
From the Michelin web site.....
"All MICHELIN® tires4 (both Replacement & Original Equipment) come with a limited warranty for treadwear, as well as a limited warranty which covers defects in workmanship and materials for the life of the original usable tread, or for 6 years from date of purchase, whichever occurs first."
To me if a company is only going to stand behind its produce for a limited amount of time I should believe them. They know more about the product then I ever would.
I rotate, balanced and air pressure check all 7 tires. I have a TPMS. I have found that the temperature of the tires is more affected by the heat from sun exposure i.e. the side that is facing the sun runs hotter than the other side. Yes anything that reduces the tire temp is good.
Bottom line I put enough miles on 'Baxter' so milage is more of a concern then age of tire.
glen
"Treadwear" is not the critical issue with tires in an RV application unless the alignment is off, causing uneven wear; an RV tire can retain viable tread when the sidewalls are dried out, cracked, bulging, checked, alligatored, heat-blasted, and ready to blow. A manufacturer's "limited warranty" against excessive treadwear or "defects in workmanship and materials for the life of the original usable tread" sounds good, but, in my experience, doesn't mean much when applied to an RV tire. If the manufacturer offered the same warranty against wear or damage to the sidewall of an RV tire, I might be less skeptical of the value of any "promise".
Another YMMV issue.
Would not a decent TPMS help avoid these tire blowouts?
No, unless the problem was caused by underinflation and the user had set up the TPMS when the tires were properly inflated.
Most tire blowouts happen almost instantaneously. Much quicker than the polling rate of a TPMS, and certainly faster than one's ability to safely pull over from a stop at 55-70 mph.
TPMS is valuable for monitoring pressures (and temperatures, if so featured) and letting you know of an underinflation or slow leak issue.
I had the same Toyo tires on my rig when I bought it. They only had about 5000 miles on them and were 6 years old. They still looked perfect. So I to decided to ignore the recommendations. On our first long trip we had one blowout and disintegrate. I learned my lesson and won’t make that mistake again.
You are probably right but I am also thinking many blowouts may have an early indications such as high temperatures.
I am wondering if you, or anyone here, actually had a blowout with the TPMS engaged? I would love to hear about it from someone that actually experienced it. It would also be interesting to see any data that compared blowouts of those using TOMS to those that don’t. Wishful thinking for something like that because there are so many variables.
Personally, I would never let my tires go longer than five years since living in Souther California means heat, and sun almost all year long. Mileage means little when it comes to RV’s and I believe “you’re only as safe as your tires.” The potential damage done from a blow-out to your rig, the possibility of real danger to the occupants, and the loss of a perfectly planned trip are more than enough to replace tires every five years. Fortunately, I’ve never had a blow-out and never want to experience that disaster.
My two-cents worth based on twelve years of RVing experience.
Jules
Jack,
You said: “I am wondering if you, or anyone here, actually had a blowout with the TPMS engaged?”
Others here have mentioned blowouts on their LD’s with no warning from their very reliable TPMS. The warning only comes after the damage has been done.
A blowout is a sudden catastrophic event. Unlike any other tire failure. As good as a TPMS is, they are incapable, AFAIK, of such a feat.
Maybe they should have a data entry for tire age and it can give you a gentle heads up. I can see it now. https://youtu.be/1IPPn9t6dyE
Kent
These pretty pictures offer a look at what can happen when an inside dual blows:
https://www.flickr.com/photos/lwade/sets/72157685899755355/
Would not a decent TPMS help avoid these tire blowouts? Usually there is a loss of pressure and certainly an increase in temperature first. Have any of these blowouts occurred with TPMS installed and was there any warning in advance?
A TPMS will detect a slow leak. A blowout is just that, the tire explodes and losses all its air at once.
Some blowouts are cause by low air pressure, others are caused by catastrophic structural failure.
We had a blowout two summers ago and the TPMS alarmed when the tire blew. I had manually checked all the tire's pressure within ten minutes of the blowout and all were within their normal operating range.
Pushing older tires to save a few bucks may work fine but, to me, isn't worth the worry, knowing how much damage a blown tire can do and how it can cause a serious accident.
I want both my brakes and tires to be in top shape, not just adequate. YMMV
Larry
I remember reading about this tragedy and gained a new respect for the destructive power of a blown, steel belted tire:
Boy Pulled to His Death Through Bus Floor - LA Times (https://www.latimes.com/archives/la-xpm-1992-05-12-me-1729-story.html)
Harold
I remember reading about this tragedy and gained a new respect for the destructive power of a blown, steel belted tire:
Boy Pulled to His Death Through Bus Floor - LA Times (https://www.latimes.com/archives/la-xpm-1992-05-12-me-1729-story.html)
Sometime when a tire blow, the tread does not immediately separate from the carcass and whips around, carving away at whatever is in the way. I have seen LDs at the Mothership with refrigerators and other appliance shredded by a blown tire.
A friend's pickup blew a rear tire and the flapping tire removed most of the side of the pickup's bed.
Most drivers have no idea what to do if a tire blow. Your instinct says to stop as quickly as possible but this can throw the vehicle out of control.
Michelin has a video that demonstrates the proper way to respond to a blow out, it should be required viewing.
https://www.youtube.com/watch?v=lkwOE1yKY5c
https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=13
Larry
Michelin has a video that demonstrates the proper way to respond to a blow out, it should be required viewing.
The above video was really helpful. I knew that in the event of a blow-out to resist braking but I wasn't aware of the "step on the gas" strategy. I really hope to avoid a blow-out and I really hope to remember to not brake while increasing the vehicle's speed. I've been practicing some mental imagery and discussing this strategy with Margee who drives about half the time. Thanks Larry for posting this valuable video.
Would not a decent TPMS help avoid these tire blowouts? Usually there is a loss of pressure and certainly an increase in temperature first. Have any of these blowouts occurred with TPMS installed and was there any warning in advance?
Pax side inner dually blew dramatically at 20,800 mi 2 yrs 1 day after delivery. TPMS alarm triggered after the !bam! Pressure stable in TPMS until event, hand checked pressure earlier in day. I-10 6 miles into LA on newly paved interstate (last 50 mi in TX under construction w/ severely terrible pavement).
Had tread separation Pax side outer dually a couple of years later. Tire maintained pressure and TPMS wasn't the key identifier - that was the WHAP sound and the sight of the tread in the side view mirror. That one was 10 miles out from home on a short trip. No cause that I could point to.
Hope this helps...
Joel
Michelin has a video that demonstrates the proper way to respond to a blow out, it should be required viewing.
This video is very old (published 2008), and I could not find it on the Michelin website, nor even any reference to "blowout", so I very much doubt Michelin recommends flooring the accelerator when a tire blows. Not only is it counter-intuitive, but could be disastrous when used by an untrained driver; for example, imagine a startled, semi-panicked driver flooring the accelerator then holding it down for 10 or more seconds as he tries to steady the motorhome before realizing he should take his foot off the gas. What was a manageable problem could become uncontrollable.
Removing your foot from the gas will allow the RV to slowly reduce speed, and when you are confident you have control, you can maintain speed as needed to get to a safe place to pull over. Slowing down is what you want to do, and I do not know why
maintaining speed will be an asset. Fortunately, most blowouts are rear ones, and the handling will hardly be affected.
This video is very old (published 2008), and I could not find it on the Michelin website, nor even any reference to "blowout", so I very much doubt Michelin recommends flooring the accelerator when a tire blows.r ones, and the handling will hardly be affected.
2008 isn't exactly ancient history and, AFAIK, tire technology has not change much since.
I'm not sure why you would assume that this method of handling a blowout is different today.
Michelin is a respected company and I would assume their advice is well tested, many times what seems to be logical isn't.
Unless conflicting evidence is available, I would assume Michelin knows best. YMMV
BTW, here is the up to date Michelin blowout video nothing has changed
How To Handle An Rv Tire Blowout | Michelin RV Tires (https://www.michelinrvtires.com/tires/tires-101/tire-maintenance-and-safety/how-to-handle-a-blowout/)
Larry
Michelin is a respected company and I would assume their advice is well tested, many times what seems to be logical isn't.
Unless conflicting evidence is available, I would assume Michelin knows best. YMMV. BTW, here is the up to date Michelin blowout video nothing has changed
I did search Michelin.com for the video, but it's not there. Turns out, RV tires have their own website (Michelin RV Tires | A Better Way Forward (https://www.michelinrvtires.com)), and the video is indeed there. The main point I wanted to make was this: Even if the procedure is better for stabilizing the motorhome after a blowout, I think untrained drivers are too likely to do it wrong, and the outcomes would be better overall if they simply lift their foot off the gas pedal. In fact, I found one RV website and three insurance websites that do not recommend flooring the gas pedal:
How To Handle An RV Blowout - Good Life RV (https://www.glrv.com/blog/tips-to-how-to-handle-an-rv-blowout/)
Tips for Handling a Tire Blowout [Video] | Travelers Insurance (https://www.travelers.com/resources/auto/safe-driving/how-to-handle-a-tire-blowout)
How To Safely Handle A Tire Blowout | GEICO (https://www.geico.com/more/driving/auto/car-safety-insurance/tire-blowout/)
How to Safely Handle a Tire Blowout | EINSURANCE (https://www.einsurance.com/journal/how-to-safely-handle-a-tire-blowout/)
Frankly, I do not see how control can be improved by maintaining or increasing speed after a blowout, rather than letting it slowly reduce by taking the foot off the gas pedal. I am willing to change my mind if that is explained to me, or I can read studies showing that outcomes are actually improved by telling drivers to floor the pedal.
I've had two blowouts with TPMS engaged. All it did was let me know which tire went, after the fact. The second one had the over temp capability and it did not alarm. No damage in either case. In one case the separated tread was still one circular piece and the second one was a sidewall failure. Both Michelin MS 2. It has always been the tire near the exhaust pipe.
I have seen massive damage from a blowout and don't want any part of that. I now use Michelin XPS Rib which is a grade above the MS 2.
The main advantage to me of a TPMS system is it keeps tire pressure on your mind and makes it easy to check. Don't expect it to save your butt on anything but a slow leak. It also lets you know when going from warm to cold you need to add some air.
I've had two blowouts It has always been the tire near the exhaust pipe.
I have seen massive damage from a blowout and don't want any part of that. I now use Michelin XPS Rib which is a grade above the MS 2.
As stated before, the passenger-side, inside rear tire is the most common position that blows out.
For most of us, the tires time out before they wear out and many owners do not bother to rotate the rear wheels. The tire nearest the exhaust is cooked for its entire life and this appears to damage the tire.
I didn't rotate the rear tires until I had a blowout, now the rear tires are rotated each year. Additional heat shields have been installed to reduce the tire's exposure to to exhaust's heat. The combination of the two will prevent any tire from enduring long term heat damage.
I'm not sure if installing a commercial grade tire will be anymore resistance to heat damage.
The XPS Rib is a summer tire, lacking a snow and mud rating. Tire Rack's XPS Rib page states " Highway Rib Summer tires are not intended to be driven in near-freezing temperatures, through snow or on ice."
https://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=XPS+Rib
We travel year round and seem to drive in snow and/or ice once or twice each winter We need an all-season tire, with a S&M rating.
Your needs may be different.
Larry
Don't do snow. I was after the steel sidewall. The last set just lasted 7 years with no problems. Hope the new set does the same. I do have heat shields but haven't rotated.
Frankly, I do not see how control can be improved by maintaining or increasing speed after a blowout, rather than letting it slowly reduce by taking the foot off the gas pedal. I am willing to change my mind if that is explained to me, or I can read studies showing that outcomes are actually improved by telling drivers to floor the pedal.
Historically, most people make horrible decisions when faced with a dangerous situation. An example would be when a tire blows out at highway speed - the absolute worst thing you can do it turn the wheel to get off the road and apply the brakes. If you do that you have made a bad situation much worse.
Applying the accelerator for a brief moment following a blowout accomplishes two very important things: 1) it keeps you going strait since your mind will be focused on acceleration and not deceleration and turning. 2) it buys you a few moments to clear your head and remember what you should be doing - maintain a straight course, engage your emergency lights, slowly let off the gas and begin to decelerate in a controlled fashion, do not turn off to the shoulder until you are down to 20 or 30 MPH.
No need to worry about uncontrollable acceleration since your rig will feel like you are dragging a boat anchor. Pressing the accelerator will interrupt your panic mode and give your brain time to load the proper set of instructions. You can practice this on a deserted road by simulating the process and laying down the proper memory track.
Historically, most people make horrible decisions when faced with a dangerous situation.
That's what causes me concern: adding something that is not the normal reaction to the problem seems like bad idea. I do not see how a person can be more focused on steering with the pedal floored, than if they lifted their foot (which is the natural reaction). Why would pressing the accelerator interrupt a panic mode, and lifting your foot wouldn't? These driver responses are speculation, and were not in the Michelin video.
Physically, I do not see how maintaining speed (or going faster, the likely result if the blowout is a rear tire, which causes very little drag) enhances steering control. If someone has a scientific explanation for better stability or easier steering, I'd reconsider my remarks. Or, show me a study that determines the outcomes after a blown tire are better overall when untrained drivers floor the pedal.
Practically speaking, it's generally a rear tire that blows, and with three good rear tires, the rig's stability is hardly affected. So, there is no fighting for control, and even using the brakes will be little different, and lifting your foot or pressing the accelerator will both work very well.
I've done the "flat tire" experiment a number of times by unknowingly driving with a flat rear tire. The handling changes so little, I've gone 30+ miles before pulling over because "something seems not quite right". Notably, the flat tire was never damaged by running flat, likely, I think, because the rim remains at the correct height.
A double rear drivers side blow out stops you real quick. Keeping a cool head avoids disaster, only had a moment to control the rig to the shoulder before we were dead in the water.
A double rear drivers side blow out stops you real quick. Keeping a cool head avoids disaster, only had a moment to control the rig to the shoulder before we were dead in the water.
What was the cause of the simultaneous blowouts? Was it two sequential "bangs", or one really loud one?
Physically, I do not see how maintaining speed (or going faster, the likely result if the blowout is a rear tire, which causes very little drag) enhances steering control. If someone has a scientific explanation for better stability or easier steering, I'd reconsider my remarks.
It has to do with momentum, and the likelihood that a blow out will cause the vehicle to cease traveling in a straight line. Maintaining forward speed while gently slowing down significantly decreases the chances of swerving out of control. The "gut" reaction of trying to come to an abrupt stop makes it more likely the driver will lose control of the vehicle.
Given that these vehicles are rear wheel drive, loss of a tire on the rear will definitely cause a drag problem on that corner.
There was a dashcam video of a diesel pusher last year that showed a drive axle blowout at highway speed. The driver appeared (based on the tail lights) to jump on the brakes. The vehicle then fishtailed left and right and went out of control and onto its side.
"Physically, I do not see how maintaining speed (or going faster, the likely result if the blowout is a rear tire, which causes very little drag) enhances steering control. If someone has a scientific explanation for better stability or easier steering, I'd reconsider my remarks. Or, show me a study that determines the outcomes after a blown tire are better overall when untrained drivers floor the pedal."
At the risk of sounding like I'm preaching or talking down to you - humbly I'm not.
It's called Physics. Let me explain .... The mass/moment is moving forward. When the FRONT tire blow, ie goes flat in an explosive manner, the mass/moment moves to the right or left depending on the side of blown tire. At this point the rig is moving in the direction of the mass/ moment. If you apply the brakes you decrease the forward mass/moment letting the side angle mass/moment increase relative to forward mass/moment. This moves the center of gravity up and over increasing the chance of an roll over. If you apply acceleration to the forward moment ie gas pedal you increase forward mass/moment relative to side angle mass/moment. This is pushes the center of gravity down on back. Increasing the control of the moving mass.
glen
My rule of thumb is to follow the guidance of the professional wisdom that prevails. If the laws of physics change during my lifetime then I will have to relearn a few things.
I follow several guidelines for tire safety.
1) Drive on good tires that have been maintained well. Not over or under inflated. Inspect for odd wear and always check tire pressure before hitting the road.
2) Don’t drive on aged out tires. 5-6 years of age is the max. That’s the wisdom of those who know. I haven’t reached that point yet with our LD, but I’m ready to go when the time comes.
3) I maintain my TPMS. That’s fresh batteries in the sensors every year. Check for any road hazard damage to the sensors and check for snugness of their installation.
4) I always do a preflight check of the repeater and the dash monitor. This takes little effort. The monitor reads data sent to it and checks that the repeater is operational. It takes 20 minutes for the scan to run. In the meantime, I run all my other preflight checks.
Have I forgotten anything? I’ll take a look at my phone where I keep all my LD data.
Here’s a YouTube that supports the outlined procedure of Michelin’s video.
https://youtu.be/kTufMmcqSwY
Stay safe and we’ll see you ‘round the campfire.
Kent
The mass/moment is moving forward. When the FRONT tire blow, ie goes flat in an explosive manner, the mass/moment moves to the right or left depending on the side of blown tire.
Your use of "mass/moment" is not one I've ever encountered, nor could I find a definition for it. Here's what I think "mass moment" (no slash) means: "The mass moment of inertia, usually denoted I, measures the extent to which an object resists rotational acceleration about an axis, and is the rotational analogue to mass." Perhaps you meant to use a different term?
My rule of thumb is to follow the guidance of the professional wisdom that prevails. If the laws of physics change during my lifetime then I will have to relearn a few things.
I follow several guidelines for tire safety.
1) Drive on good tires that have been maintained well. Not over or under inflated. Inspect for odd wear and always check tire pressure before hitting the road.
2) Don’t drive on aged out tires. 5-6 years of age is the max. That’s the wisdom of those who know. I haven’t reached that point yet with our LD, but I’m ready to go when the time comes.
3) I maintain my TPMS. That’s fresh batteries in the sensors every year. Check for any road hazard damage to the sensors and check for snugness of their installation.
4) I always do a preflight check of the repeater and the dash monitor. This takes little effort. The monitor reads data sent to it and checks that the repeater is operational. It takes 20 minutes for the scan to run. In the meantime, I run all my other preflight checks.
Here’s a YouTube that supports the outlined procedure of Michelin’s video.
I have no argument with your guidelines, but I don't think the Youtube video supports the Michelin procedure; instead, it simply asserts that is what you are supposed to do. There is no supporting evidence of it's effectiveness.
Glen,
It’s understandable that “hitting the gas” may seem counterintuitive and unless someone has had a chance to practice the outlined techniques it may be the last thing on their mind if the situation occurs.
With that, here is another video detailing the “hit the gas” procedure. https://youtu.be/8znCgvHMb-g
I’d hate to be in the drivers seat when it occurs. Stuff like that can be rather unsettling.
Kent
A front tire blowout is very similar to driving in the rain and having the right side of the vehicle drop into a big, deep puddle, the type that tries to tear the steering wheel out of your hands and turn hard to the right. The right response is to turn left and floor it until things stabilize. In England they turn left. Preventing a rollover is the ultimate goal.
A rear tire blowout usually doesn't effect the handling much, it's the noise that is shocking, first the explosion, then the sound of the shredding tire ripping up the wheel well and the floor above, BTDT.
Experiencing this once is more than enough incentive to keep the tires properly inflated, regularly inspected and changed out on time. Trying to save a few bucks can cost a fortune or your life in the long run.
I can't imagine having Lisa's dual blowout, that must have been very exciting, a definite E-ticket ride.
Larry
Your use of "mass/moment" is not one I've ever encountered, nor could I find a definition for it. Here's what I think "mass moment" (no slash) means: "The mass moment of inertia, usually denoted I, measures the extent to which an object resists rotational acceleration about an axis, and is the rotational analogue to mass." Perhaps you meant to use a different term?
<smile> without getting too too deep into calculus I added mass to moment with a / so I could make it clearer to non math folks. I, on first draft only use the word 'moment'. Moment is a math term to freeze a moving action so one can predict the future movement.
The whole point is an object or mass is moving in one direction - it will move in that direction till a a force is applied in another direction.
glen
<smile> without getting too too deep into calculus I added mass to moment with a / so I could make it clearer to non math folks. I, on first draft only use the word 'moment'. Moment is a math term to freeze a moving action so one can predict the future movement. The whole point is an object or mass is moving in one direction - it will move in that direction till a a force is applied in another direction.
Go into calculus as deep as you wish - I'm familiar with the subject; however, your description of "Moment is a math term to freeze a moving action" is still puzzling, and not one I'm aware of. Here is the definition I recall: "In mathematics, a moment is a specific quantitative measure of the shape of a function. ... If the function represents physical density, then the zeroth moment is the total mass, the first moment divided by the total mass is the center of mass, and the second moment is the rotational inertia." (Wikipedia)
Maybe you could redo your analysis of a blowout using just forces and velocities? The "moment" thing isn't working for us :(
OK, the only moment I am worried about is called the "Oh S*^t Moment" defined as the precise time of realization that I had a blowout and have to remember what to do. Us engineers like to approximate our solutions.
Mike S.
Writing this as I sit in my LD at Les Schwab waiting to get my almost 7 year old tires rotated based on advice from this group. Not ready to replace yet, which might be regretful.
RVLove posted a video about an RV graveyard. They talked about a lot of the damage seen coming from tires that were aged out and had blown.
Where RV's Go to Die. RV Salvage Yard Lessons from RV Fires, Accidents & Blowouts | RV Life (https://www.youtube.com/watch?v=Vtt41vbgwn4)
Joan - You posted something important. The tire warranty only covers the tire (and in my experience it is prorated so you really just get a discount on the next tire bought from that company). The more expensive damage is to the rest of the rig and potentially to the people inside the rig. So I err on the side of caution.
Eric and others. Escapees bootcamp teaches the same method shown in the video - accelerate than with the rig under control slow it down and drive to the side.
In fact they say the drivers job is to floor the accelerator, the passengers job is to yell gas, gas, gas (to remind the driver what to do). FYI - they now have all their bootcamp videos online, some are very good, some are things you already know, but very worthwhile for newer RVers.
Since the tire blowing is a side force, I figured we (DH & I) should practice this maneuver so it was natural if a tire blowout ever happened (e.g. like your muscles knowing how to hit/throw that ball in a sport, you don't think it through, you just do it).
As the video said, we hit side forces all the time - gusts of wind from nature/semis, etc. So on our trip from AZ to CA in March, I played with this. I tried it with some Semis and it worked fine. But I also was blessed with driving in that horrible area of nasty high gusting wind (where the windmills are to generate electricity) and it seemed a worst than typical day. We had huge gusts that would throw the rig 4' to the side if you did nothing to compensate - I would exclaim "Oh Man" loudly and floor the gas pedal trick as soon as I felt that side force. It made a huge difference, we got shoved to the side only a couple inches (huge difference between that and 4'). I found that I really didn't pick up speed - the first few seconds the speed was the same, at about the 6-7 second mark I picked up just a few mph. Not anything to worry about.
Disclaimer, I was driving a 22' (so likely smaller than yours so less side force), no Toad, and a Chevy G30 (so likely less speed pickup from flooring it than yours). And I might have gotten the pedal only 7/8 or even 3/4 to the floor sometimes, at other times I did get it to the floor. So YMMV.
But I highly recommend playing with this when in situations of side forces, starting with small ones like semi's passing so you can see and trust how it works and then go play where there are high gusts of wind. That way you not only gain confidence that this method works, but you will be more likely to not panic but automatically react with the accelerator down method.
Jane
....... But I highly recommend playing with this when in situations of side forces, starting with small ones like semi's passing so you can see and trust how it works and then go play where there are high gusts of wind. That way you not only gain confidence that this method works, but you will be more likely to not panic but automatically react with the accelerator down method.
Jane
Good idea. I know that in an emergency you will do what you practiced. Using side wind is better than on purposed blowing your tires and I might add cheaper.
glen
Since the tire blowing is a side force, I figured we (DH & I) should practice this maneuver so it was natural if a tire blowout ever happened (e.g. like your muscles knowing how to hit/throw that ball in a sport, you don't think it through, you just do it).
It's possible that flooring the accelerator is useful in the situations you describe, but a tire blowing is definitely NOT a side force. For a front tire blowout, what you feel in the steering wheel is produced by the additional drag for the blown tire (a frictional-like force to the rear, and only on the tire), compared to the good one on the other side. Wind gusts and trucks passing to put an aerodynamic side force on the motorhome, and that side force affects the steering wheel through the geometry of the front suspension. Effectively, the front wheels are "casters", and a side force tends to turn the wheels to the side away from the force on it. Drivers react by steering towards the side force.
The gusts I've encountered are over quickly (that's what makes it a gust), more quickly than I or the motorhome can respond to them by flooring the pedal. It might help when you encounter a fairly steady crosswind as you come out from behind a hill, and the wind suddenly hits you and continues to hit you, but I haven't tried it or thought it through.
Eric, the wind gusts where I practiced lasted about 5-10 seconds and it made a difference to floor the RV. DH was driving on the way back, gusts were not that bad, but he got blown 2' into the next lane over e.g. over the line) on a very bad gust. So well worth accelerating IMO. I exclaimed a lot but never went over that line. The attached picture shows the area, I know many in S. CA are familiar with that stretch of road east of Los Angeles. I didn't feel the steering wheel turn under my hands (what you seemed to be saying.. the tires would turn which would turn the steering wheel), I would feel the entire LD move to the side, like blowing on a tiny box (with no wheels on it). By accelerating I barely needed to move the wheel at all to "course correct". [Yeah, I do the old 10 and 2 o'clock on the LD, something I haven't done in decades in a car.]
Escapees bootcamp from what I remember, explained it as you are moving forward with a force. You now have a new force pulling your rig in a different direction. Increasing the forward force (making it larger) means it is more likely to be dominate and keep you going in that direction. They also said the tire typically doesn't come all the way off (e.g. you are not riding on rims would be different friction than a collapsed tire) and can typically slow down and then if needed drive a mile or two to get off the road to a safe place to get the tire changed (e.g. not forcing a tire change on the freeway shoulder).
I would describe what Escapees presented as the tire blew and yes it is now causing more friction/dragging/slowing on that corner of the rig. I would guess the rig would react by spinning towards the direction of the tire - e.g. trying to make a circle around the tire that is blown - but it doesn't just do a tight circle as the force of our nice heavy LDs going forward is pretty high (the reason smaller cars lose big time in wrecks, even if the other car is just one size bigger than yours). Instead we start a slow spin (mostly forward but now twisting to the side).
Our goal is to keep the rig going straight forward.
So Escapees said if you push the accelerator down, you are increasing the force to go straight forward to keep this force larger than the one the blown tire is causing (with it's drag) so that you are driving straight as possible until you get past the panic and have corrected your steering and can start to slow down safely.
Braking right away reduces the forward force (and changes the ratio of forward force vs spin around that tire force) so that we are more likely to do a bigger spin/twist around.
It does not accelerate the vehicle much (takes a lot of acceleration to make our LDs go faster as they are heavy), it just increases the forward moving force so we are less likely to spin.
So, if Eric says it is different, for those who have had blowouts - how much directional force did you feel (before any braking or course correction)? A small pull to the side, a huge pull to the side, a huge pull backwards, or ......? Anyone have it happen and still stay calm so they could observe the force? :D
I didn't feel the steering wheel turn under my hands (what you seemed to be saying.. the tires would turn which would turn the steering wheel), I would feel the entire LD move to the side, like blowing on a tiny box (with no wheels on it).
Think about the times you drove in a strong, steady wind coming from the side: you had to hold the steering wheel turned some towards the side the wind is coming from, compared to driving in no wind. The same forces are there with a gust, but don't last as long, and perhaps that's why you don't notice it. I notice the "twitch" in the steering wheel every time there is a gust, and my reaction is reflexive - I resist it without even thinking, which I think most everyone does.
I sent the Michelin video to a long time friend of mine, worked 15-20 years as a tire and vehicle stability engineer for a large company, then continued in the field after retirement. Here is his reply:
I did get a look at it. It was like old home week. The Nevada Automotive Test Center was where I worked part time after I retired. I recognized the motor home in the video. That video, which I have seen before, has to be over 20 years old. Where did you find it?. I remember Henry Hodges Sr, (long since passed on) promoting the practice of hitting the gas with a blowout. He never could rationally explain (to my satisfaction) the engineering of why. Fortunately the Michelin video suggests you back off the gas before you gain "any" speed. NATC did testing for Michelin in those days.
Loosing a front tire is less risky than loosing a rear, assuming one holds the vehicle on the road, which nowadays with effective power steering is not hard. The worst that can happen is a modest under-steer. I believe best practice is to keep the steering straight and gradually reduce speed. Right front rapid tire pressure loss happened to me in our previous motor home. The speed was modest, probably 55 to 60, It was not a blowout but was a failed valve stem. The result was quite benign. There was a slight pulling to the right and a road roughness that felt like we were driving on a rumble strip. We were on a two lane road just south of mount Shasta on our way to Carson City, at night. Getting the spare (which was nearly out of air) installed was a considerable adventure. I doubt if I could do it now. When we got to Carson City we got everything fixed, including the very slow leak in the tire which was the spare.
So, I'll stick to my belief that flooring the pedal has no value. Here is some info on Henry Hodges Sr:
Mr. Henry C. Hodges Sr., Ordnance Corps Hall of Fame Inductee 2009, U.S.... (https://goordnance.army.mil/hof/2000/2009/hodges.html)
So, I'll stick to my belief that flooring the pedal has no value.
Since this discussion is just going around in circles, it's time to end it.
The 'facts' from both side have been presented. It's up to the individual LD owner to decide how he/she want to approach a blowout.
Let's move on.
Larry