Lazy Daze Owners' Group

Lazy Daze Forums => Lazy Daze Technical => Topic started by: tedeboy on January 03, 2018, 01:56:44 pm

Title: Tire pressure
Post by: tedeboy on January 03, 2018, 01:56:44 pm
Just to confirm.
Fill to the recommended pressures as indicated on the tag inside the driver's side door frame.
Correct?
Title: Re: Tire pressure
Post by: Jota on January 03, 2018, 02:03:31 pm
I always fill based on information directly on the tire.
Tires often change and sometimes not to specs of manufacturer sticker.
Title: Re: Tire pressure
Post by: Kent Heckethorn on January 03, 2018, 02:04:17 pm
I have followed the guidelines as included in my LD manual. Tire pressure is, from my understanding, dependent on the weight of the LD per axle.

Here is a pic of the manual outline.
As well as the print out from RV Weigh that weighed each wheel set of my 27’ RB.

Kent
Title: Re: Tire pressure
Post by: Lazy Bones on January 03, 2018, 02:13:59 pm
"Fill to the recommended pressures as indicated on the tag inside the driver's side door frame.
Correct?"

Is that before or after you've loaded wife, 5 kids, Dad's tool assortment and Grandad's rock collection?   :o   ::)
Title: Re: Tire pressure
Post by: tedeboy on January 03, 2018, 03:10:12 pm
We need to weigh before each trip?
Seriously?
Where?
Title: Re: Tire pressure
Post by: Lazy Bones on January 03, 2018, 04:12:16 pm
"We need to weigh before each trip?"

It's really not that complicated, weigh once with full propane and fresh water. Estimate the weight of  what will be added, passengers and gear. Combine the measured and the estimated for a full measure, consult the tire manufactures weight/pressure charts, adjust as necessary and have a good trip.

I have found through long experience that my 30'IB does well with 65# front and 75# rear which satisfies the pressure needs as well as my comfort. And the tires wear well at those pressures so all is well!   8)
Title: Re: Tire pressure
Post by: Larry W on January 03, 2018, 04:17:07 pm
We need to weigh before each trip?
Seriously?
Where?
The suggested way to set the tire pressure is to load the rig up, as you you have it when leaving on a long trip.
Take the rig to a weight station, such as a Cat Station, found at many truck stops.
CAT Scale Locator | CAT Scale (https://catscale.com/cat-scale-locator/)
Have the front and back axles weighted and then use the tire pressure tables, found in your LD Owner's Manual, to find and set the recommended pressure. 
You do not need to do this often, just when you change the way things are stored in the rig or when adding more weight.

Cats Stations only provide the weight of an entire axle, not individual wheels.
If you ever get a change to get the four wheels weighted individually, do it. This service is often available at RV rallies.
Individual wheel weights allow you to better balance the load, side to side, for the best handling and even tire loading.

Larry
Title: Re: Tire pressure
Post by: tedeboy on January 03, 2018, 04:53:00 pm
The suggested way to set the tire pressure is to load the rig up, as you you have it when leaving on a long trip.
Take the rig to a weight station, such as a Cat Station, found at many truck stops.
CAT Scale Locator | CAT Scale (https://catscale.com/cat-scale-locator/)
Have the front and back axles weighted and then use the tire pressure tables, found in your LD Owner's Manual, to find and set the recommended pressure. 
You do not need to do this often, just when you change the way things are stored in the rig or when adding more weight.

Cats Stations only provide the weight of an entire axle, not individual wheels.
If you ever get a change to get the four wheels weighted individually, do it. This service is often available at RV rallies.
Individual wheel weights allow you to better balance the load, side to side, for the best handling and even tire loading.

Larry

Thanks Larry.
I don't recall a chart in my 1995 manual but I'll recheck.
Title: Re: Tire pressure
Post by: Larry W on January 03, 2018, 06:10:33 pm
Thanks Larry.
I don't recall a chart in my 1995 manual but I'll recheck.
Almost every tire manufacturer has their pressure charts available online.
Here is the Michelin RV Tire manual, it has pressure charts for all of Michelin's RV tires
https://www.michelinb2b.com/wps/b2bcontent/PDF/RV_Tires_Brochure.pdf

Larry
Title: Re: Tire pressure
Post by: tedeboy on January 03, 2018, 09:17:14 pm
Almost every tire manufacturer has their pressure charts available online.
Here is the Michelin RV Tire manual, it has pressure charts for all of Michelin's RV tires
https://www.michelinb2b.com/wps/b2bcontent/PDF/RV_Tires_Brochure.pdf

Larry
I have Goodyear Wrangler HT LT225/75R16.
I'll look around online for a chart.
Thanks.
Title: Re: Tire pressure
Post by: rodneyhelfrich on January 04, 2018, 12:00:50 am
My alternate method of seting tire pressure is take the door plate pressures and add 5 psi.  At the same time measure read depths side grooves and middle groove  of the tread.  In 6000 miles repeat.  Excessive side Groove wear indicates the need for an additional 5 psi.  Excessive middle groove wear indicates the need to reduce the tire pressure from the previous setting.  All the while never exceed the maximum pressures not weights on the sidewalls.  I learned this from the old 4 Day Tire Stores of yesteryears.
Title: Re: Tire pressure
Post by: paul banbury on January 04, 2018, 01:09:32 am
As always, what Larry said.

Other weighing options include state operated truck scales, in some states, when they are closed one can pull on and get readings. I do this in Washington and have done in Oregon. Others may too have suggestions on this.

Local aggregate (gravel, dirt, etc) companies will also weigh.

Using the recommended pressure for the weight I run improved handling on our LD mucho. The maximum pressure tire shops like to fill to made ours less forgiving to drive. The manufacturer recommended pressure was just a bit less than is on the door tag of our 1992.
Title: Re: Tire pressure
Post by: Blueox25 on January 04, 2018, 11:27:28 am
We don't have a convenient Cat Scale nearby, but I found that nearly any moving company that has moving vans also has a truck scale.  The two companies in our small town are receptive to weighing RV's and because I don't need a certified tag, they have never charged me anything for the service.  I go in mid-day when their trucks have already been dispatched and there is no traffic in the yard.  I weigh the rig front axle only and then rear axle only and set my tire pressure according to the table in the LD manual.

I always leave a cash tip to person in the weigh office equal to their weigh fee.  Everyone seems happy with the arrangement.

The pressure recommended by the LD manual for the weight of my axles is lower than the pressure on the side of the tires.  This pressure does, however, give the rig a comfortable ride and the wear seems to be uniform.  At this point I am running 65psi on the front and 75 psi on the rear.

HD
Title: Re: Tire pressure
Post by: Ross and Beverly Taylor on January 04, 2018, 04:47:14 pm
Once I have decided on what the correct weight is,  I adjust pressure up 5 lbs to give me some leeway as to when to add air.
Title: Re: Tire pressure
Post by: tedeboy on January 07, 2018, 04:52:45 pm
Here's what my manual says...

(https://s5.postimg.org/b6ojo6ex3/20180107_135028.jpg)
Title: Re: Tire pressure
Post by: LD-TED on January 11, 2018, 09:17:30 pm
I have Michelin tires.  I printed out Michelin's front and dual rear axle weight tables for my tires and taped it to the dash under the steering wheel for ready reference.  I would argue that the manufacturer's load/pressure specs for a specific tire would be the most accurate, safest standard.  Anyone disagree?

FYI, for my 2004 rear bath, I find that 65 front and 75 rear generally meet the rolling requirement.  I do have hydraulic levelers, an aftermarket airbag rear suspension, a 2016 Subaru Forester toad (Roadmaster Sterling towbar), and two adults (plus supplies).
Title: Re: Tire pressure
Post by: Michelle C on January 12, 2018, 10:35:41 am
As always, what Larry said.

Other weighing options include state operated truck scales, in some states, when they are closed one can pull on and get readings.

Wheel Position Weighing (http://www.rvsafety.com/wheel-position-weighing)

A couple of options which will get you corner weights - highly recommended, BTW.  You want to get weights, as loaded for a typical trip, with all usual passengers in their usual locations, and whatever attached to your rear hitch if you carry or tow anything.  Then compare the results to the load and inflation tables for YOUR SPECIFIC TIRES - model, size, and load range.  From past experience, RV Safety will include a copy of this with your final report.

Weighing Schedule (http://www.rvsafety.com/weighing/weighing-schedule)

if you're an SKP  SmartWeigh (https://www.escapees.com/knowledge/smartweigh)