Grit dog
Black Diamond, WA
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Golden_HVAC wrote:Ford put the same sticker on every E-350 they produce, and they know it will be put into a RV chassis, and should be close to the maximum GVWR. So if Ford says 65 PSI, that will give the most comfortable ride. 80 PSI and it will feel more bumps in the road. The tires should last 7 years - and you normally do not wear them out in that time.
You really should not keep the tires once they are 7 years old.
Fred.
Well, fortunately the OPs rig won’t have 7 year old tires for like 5 more years likely. But the “when to replace my tires?” recent threads could maybe use your advice, but not this one.
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
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Desert Captain
Payson
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enblethen wrote:first thing you need to do is weigh the rig ready for the road. Gear on board, fresh water and the like.
Then go to the tire manufacturer website and get the inflation chart.
Inflate the tires according to that.
I run five pounds over chart indicated pressure!
Winner,Winner, Winner! Ding, Ding, Ding! It is just that simple. ![[emoticon]](https://forums.motorhome.com/sharedcontent/cfb/images/doh.gif "doh")
For the record I have 24' E-350 Class C, GVWR 11,500# and run at or very near that often towing a 2,500# Cargo trailer. 60 psi for the fronts and 65 for the rears gives me a 5 - 10 percent fudge factor and a very smooth /stable ride.
The folks who place the door tags have no clue how you are going to load/use your coach. The kid who recommended 80 psi is an idiot as that will guaranty a horrible ride. Over inflating the fronts will make the steering loosey/goosey as it reduces the contact patch.
Opinions vary as to when but tires time out, often long before they wear out. Had a tire grenade doing $4,181 in damage {it blew the wheel well right up through the bottom the coach}. It was less than 6 years old and had been inspected by Discount tire the previous day, had 6/32" of tread, looked great and was aired for the load carried. I now replace my RV 's tires at no more than 5.5 years and yes I live in Arizona which is a "challenging" environment {to say the least} for tires.
Folks who actually use their RV's on a regular basis will often approach wearing them out {5.5 years for us is easily 40,000+ miles}. I just replaced all 4 of my duallies with Michelin Agillis Cross Climates {my front tires and spare are all Agillis CC's and just a little over 2 years old}.
As noted,... Opinions and YMMV.
![[emoticon]](https://forums.motorhome.com/sharedcontent/cfb/images/cool.gif "cool")
* This post was
edited 04/14/23 09:31am by Desert Captain *
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Cruisineasy
Hayward
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I have a 2011 31' Jayco Greyhawk. I used to set the tire pressure at 80psi all around. The front always felt like it was drifting. Not much fun to drive. I lowered the front to 75psi. Made a world of difference.
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Matt_Colie
Southeast Michigan
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When someone says "tires" near me, I always ask if said person has heard of Roger Marble.
Roger is a very interesting guy. I know I captured him for a bunch of answers to some of my "Forever Questions" about tires one afternoon at an FMCA Rally.
So, if you want to know what really matters, look up what he has written and take it to the bank.
Matt_C
Matt & Mary Colie
A sailor, his bride and their black dogs (one dear dog is waiting for us at the bridge) going to see some dry places that have Geocaches in a coach made the year we married.
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Grit dog
Black Diamond, WA
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Or literally just know your weight (approximately is ok) and know how to read a tire pressure chart.
It’s one thing for someone who understands absolutely nothing about vehicles to drive a little car around. It’s another if you’re responsible for operating a large vehicle.
Just because the govt doesn’t mandate training or licensing to try to ensure operators aren’t totally ignorant to the basics isn’t an excuse for not being knowledgeable enough to do basic pre trip inspections and have basic knowledge about particularly safety items like tire pressure.
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way2roll
Wilmington NC
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Cruisineasy wrote:I have a 2011 31' Jayco Greyhawk. I used to set the tire pressure at 80psi all around. The front always felt like it was drifting. Not much fun to drive. I lowered the front to 75psi. Made a world of difference.
Was this adjustment made on any determining facts or just from the hip? Without weighing the rig and comparing against the tire manufacturers charts, it's just a guess. Personally I find advice based on a guess is a bad idea.
2023 FR Sunseeker 2400B MBS
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Grit dog
Black Diamond, WA
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way2roll wrote:Cruisineasy wrote:I have a 2011 31' Jayco Greyhawk. I used to set the tire pressure at 80psi all around. The front always felt like it was drifting. Not much fun to drive. I lowered the front to 75psi. Made a world of difference.
Was this adjustment made on any determining facts or just from the hip? Without weighing the rig and comparing against the tire manufacturers charts, it's just a guess. Personally I find advice based on a guess is a bad idea.
Yet it’s of almost no significance because if 75 psi cold is too low and makes a discernible negative difference in steering then 80 is likely overloaded as well. And 75 cold is close to 80 with tire heat and over 80 if ambient is warmer as well.
So it’s not a “bad” idea. A bad idea might be thinking a much lower pressure is appropriate without at least knowing a ball park weight.
It’s not rocket surgery. And load/inflation tables are merely a starting point for the min safe pressure vs weight for ALL conditions. There’s acceptable adjustability each way depending on actual conditions.
OP was/is nowhere near shooting himself in the foot by shooting from the hip….except maybe in the minds of some rvnet members.
Or think about it the old fashioned practical way. What % of passenger vehicles or even commercial vehicles are out there pounding the pavement every day with totally unknown tire pressures? The answer is a shat load of them. And aside from the extremes like driving on a half flat tire, how many end up on the side of the road with a low pressure blowout? Objectively, very very few. A very minuscule fraction of 1% at best.
Now is it better to be informed and diligent? Absolutely. But there’s a huge range of acceptability between being super diligent and obtusely negligent.
And the feller who consciously adjusted his tire pressure a small amount and knows and checks pressure (obviously) is real close to the super diligent end of the spectrum.
Saying it’s a bad idea as a sort of blanket statement is just over reacting.
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way2roll
Wilmington NC
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Grit dog wrote:way2roll wrote:Cruisineasy wrote:I have a 2011 31' Jayco Greyhawk. I used to set the tire pressure at 80psi all around. The front always felt like it was drifting. Not much fun to drive. I lowered the front to 75psi. Made a world of difference.
Was this adjustment made on any determining facts or just from the hip? Without weighing the rig and comparing against the tire manufacturers charts, it's just a guess. Personally I find advice based on a guess is a bad idea.
Or think about it the old fashioned practical way. What % of passenger vehicles or even commercial vehicles are out there pounding the pavement every day with totally unknown tire pressures? The answer is a shat load of them. And aside from the extremes like driving on a half flat tire, how many end up on the side of the road with a low pressure blowout? Objectively, very very few. A very minuscule fraction of 1% at best.
Given that TPMS has been mandatory on all vehicles (including commercial buses) for over 20 years I doubt there are many vehicles at all where the car doesn't at least know it's own psi and issues warnings if it's too far out of a safe range. The car won't let you guess. On my wife's CRV that range is very narrow as a drop in ambient temp usually trips the low psi warning. Oddly enough and to the point, RV's are one of the few vehicles on the road that are not required to have a TPMS and thereby must be managed manually. So adjusting on the fly in a MH really is a guess and there's no system to tell you you're wrong. Unless you have an after market TPMS, And if you are diligent enough to have one of those, you probably take the time to set the psi properly.
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CWilson
Beach
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Second Chance wrote:On what was the "young tire tech" basing his recommendations
Perhaps his years of personal experience driving his 3rd hand Kia daily to Wendys when he had a previous position as a burger tech.
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Grit dog
Black Diamond, WA
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Well TPMS hasn’t been mandatory for over 20 years. But it has been since 08 IIrC. And only for under 10k gvw vehicles. Although I think within the last year it is or will be mandatory for larger vehicles and trailers.
Now many light/med duty vehicles over the last 15 years do have tire pressure monitors motoring but no warnings and thresholds. Like a class C rv
So to your point yes many vehicles have some sort of tire monitoring capabilities whether operable or not. So whatever.
Heck I have only 2 out of 9 vehicles/trailers that even have tpms capability and 1 of the 2 can’t use the TPMS because it’s preset way too high. I actually had to delete the monitor screen from the display to keep from clearing the low pressure warning every time the ignition is cycled.
My point had nothing to do with Tpms anyway though. But good re-direct, albeit wholly inapplicable to the discussion since knowing pressure in no way ensures it’s the right pressure, or even close, in all vehicles like class 2-3-4 trucks and vans.
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