Tow vehicle tire pressure

[dogdrs]

I know this subject has been discussed before and I have read many threads about it, but now I'm really confused. On my first truck, it was simple because the door sticker recommended the rear tires at 80psi, which was the max pressure listed on the sidewall. So that's the pressure I kept them at when towing my 5er. My 2nd truck recommended for max cargo carrying capacity to run them at 70psi and I called Michelin and they Said that was correct for towing, even though max pressure was 80, so that's what I did. I have upgraded to a dually and the sticker recommends 70psi on front, 65psi rear.(Sticker says nothing about tire pressure for achieving max carrying capacity) I guess it's lower in the rear because of the combined wt. bearing of the 2 tires. I decided to check with Michelin to confirm that this was for towing and had a web chat with "Catrina". After she "researched" it she told me that the sticker was correct but only for "every day driving" and to increase it "as necessary" when carrying a load!? I've NEVER heard this before and how would I know how much to increase the pressure. The max pressure on all the tires is 80psi but I don't think the rear tires should need to be that high. Am I wrong? I've never had a dually before so am looking for some experienced advice.

[JIMNLIN]

When your talking with a tire maker rep and you mention the vehicles tire placard psi/size/type/etc they generally will recommend what the vehicle sticker says.
Its a liability thing.

Now if you don't mention the tire placard then the liability issue isn't there anymore and they generally can give you their recommendations.

Just another example of folks with tons of experience such as a forum using the product can give better input to new folks than a tire or vehicle rep. No disrespect to a rep as they have to be very careful what they say or recommend in this area.

[dogdrs]

Thanks all for the replys. I usually run the tires at lower pressure when not hauling, and then at the pressure printed on the sticker when fully loaded. I don't think the adviser at Michelin knew what she was talking about, which is a shame. You'd like to think you could get accurate info from the manufacturer!

[SoCalDesertRid1]

Most dually pickups (except those running 19.5" wheels) can run the rears at 65 psi loaded, since the 4 rear tires' combined load capacity usually far exceeds the truck's rear axle weight rating.

[JIMNLIN]

Many mid '00 era trucks and older don't have a tire placard payload/psi sticker. Those numbers are a recommendation anyway as the truck maker has no idea how much load we carry.
My current '98 3500 DRW crew cab 4wd 454 truck doesn't have one.

How much pressure depends on how much load on the tires and the tires size/load range.
The tires on this particular DRW truck are LT235/85-16 E at 3042 lbs capacity.

I weigh all my trucks front and rear axle weights loaded and empty so I have a base line to work a psi number.
I use 65 psi in the front loaded or empty as hitch loads doesn't affect front axle loads.
In the rears I use 45 psi when empty and 70 psi when carrying max axle loads.
I have a air compressor so adding or removing air isn't a issue for me.

Now when I had several DRW trucks on the road pulling heavy GN trailer I kept all tires at max sidewall pressures 24/7 for low rolling resistance and cooler running.

[rhagfo]

The yellow sticker on the "B" pillar is the tire inflation needed for Max payload. Stop and look at ALL the numbers on your tire! Not only the Max pressure, BUT the weight rating at max pressure! On a dually the weight rating of the tire at max pressure will far exceeds the axle rating!
To those S that blindly run all TV tires at max pressure may be greatly reducing the tires contact patch with the road, leading to wheel spin when starting out and skiding when braking. There is greater chance of sliding during cornering!

Max pressure is just that max to carry the max load rating of the tire, if you are carrying less than the max load you don't need max pressure.

I don't run any of my LT tires at max as they are not near the max load.

[HuckleberryHunt]

I don't have a dually, but have always run the pressure where I felt it was best. I put LT load range D tires on my 1/2 ton. Those have a max pressure of 65 PSI, but I never went that high as they were overkill for the truck/application. For heavy loads or towing the trailer, I'd run 60PSI. For everyday driving I'd usually run about 45-50 PSI. The tire company, Les Schwab, that installed them recommended lowering the pressure for everyday driving too and would set them at 40-42 when I went in....I liked it a little more than that. When I inquired about the recommendation of running max pressure, they said no, alter it to fit the load. I did find if I ran high inflation without a load for too long I'd get excessive wear int he middle of the tread. It was nice to have the excess load rating there when I needed it, but nice to air down the tires to soften things up a bit the not. I got 85K miles out of those tires....siped when installed.
I now have a 3/4 ton diesel with load range E. I run 60psi around town and air up to 70 with the trailer/load. Not enough time on them to determine if that's the right fit yet.

[GoPackGo]

Looks like you have an F350 dually, as do I.

I've been fulltiming for 3 years with my 2013 F350 dually and all I can tell you is that I air up to the door sticker and don't go higher. I tow a fiver with a GVWR of 14k.

53,000 miles on the truck now and replaced the OEM tires (Generals) earlier this year. The rears wore evenly and probably would have made the 50,000 mile mark but I replaced a little early for peace of mind. I put on a set of Michelins, but still go by the door sticker.

[dogdrs]

I have not weighed yet as I just got the truck and have not towed with it yet. My understanding is that weighing the truck when towing is to make sure you're not over weight for the truck. I think the tire pressure is another issue(?)

[Colo_Native]

Have you weighed the truck front and rear towing that would be the first place to start I think. I don't have a dually but I run the rear 80(max psi for load) and front about 70