Wanted to get some opinions out there. When towing a moderately heavy load (7500-10,000lbs), what pressure do you you run the rear tires on the TV at? The manufacturer rating for the TV, sidewall max, or somewhere in between?
I have my F250 tires set a 80 psi...which is the max cold on the sidewall of the tire...my fifth wheel loaded around 9,500 lbs ...last Saturday i took the truck out of the garage..hitched up ..and overnight the air temp had dropped to 18 degrees.. 6 am Sunday morning...after going down the road for 5 miles the tpm light went on ...my tires had a pressure reading of 60lbs.. I.had to inflate all 4
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2014 Crusader 325 TE....2012.. F 250.. Supercab XLT, 4x2 , diesel....days camped 2011 ... 28.... days camped 2012...115 ... days camped 2013...155...2014...171 and counting
If you do not know the actual load being supported by the tire, then run maximum cold inflation pressure on the tire sidewall.
If you know the actual tire load, then use the manufacturers tire pressure chart for your tire size, range and load as the cold inflation pressure for best ride in addition to load carrying.
An example of a manufacturer's chart is attached.
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
Just curious why you would run the max recommended on the tire vs what the TV manufacturer has on the sticker in the door for the max tire pressures? My F250 has a max of 65psi for a gvwr of 9600lbs. However I have seen others with the 10k gvwr have higher recommended pressures and my 08 Ram 2500 megacab had 60/70 for an 8800lb gvwr. I believe the tire sizes have something to do with this as well as the Dodge had 265 70 17's LRE (rated at 3195lbs max at 70psi 3005lbs) and the Ford has 275 65 18's LRE(rated at 3415lbs max so at 65 psi are rated for 3000lbs). So it would seem size matters in this case. Granted nothing wrong with running the tire makers max but just curious why you would if we practice what we preach and keep our TV well within it's ratings then the safe numbers the TV manufaturer provides should easily be with spec to haul our loads.
I have Michelin tires and this is what they have to say.
Using my GMC Sierra 2500HD with Duramax diesel engine SRW as an example.
Door post sticker:
LT 245/75R/16 tires (MAXIMUM PRESSURE 80 PSI Cold Inflation Pressure)
front - 60 PSI (supporting a load of 2480 pounds per tire) 4,960 pound axle
rear - 80 PSI (supporting a load of 3042 pounds per tire) 6,084 pound axle
However,
The maximum GVWR is 9300 pounds; not 11,044 pounds.
My actual weight (NOT TOWING)
Front Axle - 4160 (or 2080 pounds per tire)
Rear Axle - 3600 pounds (or 1800 pounds per tire)
To support the actual load according to the attached Michelin recommended tire pressure (truck not towing) the front should be 50PSI and the rear should be 40 PSI.
If pressures are at door sticker 60/80 the truck is a beast on rough roads, skidding and bouncing to the point control can be lost easily on washboard roads (especially on a down hill slope).
I typically run 55/65 when not towing as that gives me a reasonable ride and handling, though I still get a pretty good bounce out of the rear.
When towing my 5th wheel camper, ACTUAL AXLE weight:
Front: 4180 pounds (or 2090 pounds each tire)
Rear: 5100 pounds (or 2550 pounds each tire)
Using the chart, 55 PSI still works for the front (I run the recommended 60 PSI anyway) and the rear at 65 (Michelin recommended) but I run at 70 PSI which provides me with a safety margin yet limits "chucking" and bouncing that I see at 80 PSI.
As you can see, 60/80 is "safe" for the maximum GVWR of my truck (9300 pounds - including the maximum axle loads front and rear). A different pressure set up works much better for me since I know exactly the load on each of my tires towing and empty.
You of course can run anything you please, but you asked why I don't use the pillar pressures and this is my logic.
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
Thanks,
No I've looked none of the doors or frames, glovebox, & being I bought it used the manual was gone. The good its an 05 with 53K (When I bought summer 2011 it now 63K). It has some custom paint work.
The tires that were on it my tire guy had a fit & couldn't believe they worked. P rated & bigger than stock. Its a duelly. Now I replaced all six as they were worn out anyway.
Thanks,
Apparently the was a tire inflation guide (& the door sticker) that were origionally with the truck. I have neither. Gives me a place to look further. Going back to that site....
Thanks again, Dave
I've been doing alot of assuming with this truck but you know what that gets ya......
Using my GMC Sierra 2500HD with Duramax diesel engine SRW as an example.
Door post sticker:
LT 245/75R/16 tires (MAXIMUM PRESSURE 80 PSI Cold Inflation Pressure)
front - 60 PSI (supporting a load of 2480 pounds per tire) 4,960 pound axle
rear - 80 PSI (supporting a load of 3042 pounds per tire) 6,084 pound axle
However,
The maximum GVWR is 9300 pounds; not 11,044 pounds.
My actual weight (NOT TOWING)
Front Axle - 4160 (or 2080 pounds per tire)
Rear Axle - 3600 pounds (or 1800 pounds per tire)
To support the actual load according to the attached Michelin recommended tire pressure (truck not towing) the front should be 50PSI and the rear should be 40 PSI.
If pressures are at door sticker 60/80 the truck is a beast on rough roads, skidding and bouncing to the point control can be lost easily on washboard roads (especially on a down hill slope).
I typically run 55/65 when not towing as that gives me a reasonable ride and handling, though I still get a pretty good bounce out of the rear.
When towing my 5th wheel camper, ACTUAL AXLE weight:
Front: 4180 pounds (or 2090 pounds each tire)
Rear: 5100 pounds (or 2550 pounds each tire)
Using the chart, 55 PSI still works for the front (I run the recommended 60 PSI anyway) and the rear at 65 (Michelin recommended) but I run at 70 PSI which provides me with a safety margin yet limits "chucking" and bouncing that I see at 80 PSI.
As you can see, 60/80 is "safe" for the maximum GVWR of my truck (9300 pounds - including the maximum axle loads front and rear). A different pressure set up works much better for me since I know exactly the load on each of my tires towing and empty.
You of course can run anything you please, but you asked why I don't use the pillar pressures and this is my logic.
Thanks Herk,
That is what I way trying to get across in my post was why people do different things. My old Dodge had a light load setting on the TPMS and you could run 45psi in the rears as long as you only had 2 passengers and no cargo in the truck. Always thought that was hokey till I read that Toyo pdf that states LT tires need more air to carry the same load as a P metric. The Super Duty rides so much better with the Michelins that I just leave them at 65psi all the time.
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John & Deb
2011 F250 Lariat FX4 Crew Cab 6.2
2011 Flagstaff V-Lite 30WRLS
Just an opinion...........
Alot of it is what one is comfortable with (within reason), as there are numerous combinations of trucks & trailers. The previous owner of my truck (05 Dodge 3500 duelly) took several of the leave springs out including the helpers & went with air bags.....assuming to make the ride better. The fiver rails were in the bed. I was not at all comfortable with that with my trailer (35 ft with a pin weight just under 3000lbs) & found a donor truck & put the springs back along with heavier rated tires. Personnally I don't notice that much difference in ride but I do not drive it daily. I know some would notice the difference. I had been running near the tire manufactures air pressures. But again I don't drive it daily & often have one of my trailers hooked to it.
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