Tire pressure

[Bluelinebuild]

Lots of false information regarding tire pressures when going to an LT tire from a P metric. Definitely NOT the pressure on the placard, you'll kill both your rolling resistance (MPG) and the outside edge of your tires. Toyo made a chart specifically for this, and is very helpful.

https://www.toyotires.com/media/2125/application_of_load_inflation_tables_20170203.pdf

In short, look at your OEM tire size and pressure on the door. For me it was 285/45/22 @ 36 PSI = 2416lbs. I made the switch to a 35x12.50x20, so I take that 2416 to that tire size which takes me to 43ish PSI (right between 40-45). I run the front at 48 being a little heavier, rear at 43. When i am towing, i bump the rear up to 50PSI.

If your stock tire size was 275/55/20 @ 35psi (just guessing) that would equal 2403lbs on the chart. Take that 2403lbs to your new LT275/65/20 which gives you 2475 @ 45PSI. So you'd want to give your tires 45PSI for the right load. Now you can adjust a little bit since these are trucks and not a 50/50 weight distribution, you should run a little higher in the front than the rear. Maybe 50F/45R. All depends on your gross axle weight. Every other method is really guessing, the chalk test when brand new can be helpful however can be tough to get truly accurate.

Hopes this helps.

Awesome info. Thank you

 

[bingo23]

Awesome info. Thank you

Alxmlr's info is mostly correct, but the reference to the 2403 lbs only pertains to the 'P' version of a 275/55R20 tire which has a load index of 111. If you have 275/55R20 tires without a 'P' in front, then the tire has a load index of 113 and carries 2535 @ 36psi. There are separate load charts for 'P' and 'non-P' versions of tires. There's also a 10% reduction in load capability when switching from Passenger tires to LT tires. This is referenced in the Toyo write up on page 11 of the pdf where it says 'P-metric to LT-metric '

The calculator referenced before takes all this into consideration and does it for you. As long as you input the exact sizes, including 'P' or non 'P' the load 'SL' or 'XL' and LT or not.

Tire Pressure Calculator

Easy to use tire pressure calculator. Use our tire pressure calculator to calculate the new tire pressure needed when changing tire sizes.

tiresize.com

 

[Alxmlr789]

Alxmlr's info is mostly correct, but the reference to the 2403 lbs only pertains to the 'P' version of a 275/55R20 tire which has a load index of 111. If you have 275/55R20 tires without a 'P' in front, then the tire has a load index of 113 and carries 2535 @ 36psi. There are separate load charts for 'P' and 'non-P' versions of tires. There's also a 10% reduction in load capability when switching from Passenger tires to LT tires. This is referenced in the Toyo write up on page 11 of the pdf where it says 'P-metric to LT-metric '

The calculator referenced before takes all this into consideration and does it for you. As long as you input the exact sizes, including 'P' or non 'P' the load 'SL' or 'XL' and LT or not.

Tire Pressure Calculator

Easy to use tire pressure calculator. Use our tire pressure calculator to calculate the new tire pressure needed when changing tire sizes.

tiresize.com

Got it, wasn't sure what the load range was for the 275/55/20 so was just guessing. That calculator is helpful too, didn't know about that.

 

[Diamondback]

Maybe you guys can help me out here. Just made the switch to yokohama geolander M/T tires. Max psi is 80 psi according to the sidewall and of course the door jam states 36 psi for factory tires. My question is what psi would be best 80 psi seems crazy high but with an 80 psi rating, 36 psi seems to low. Anyone know what psi I should be running at. I searched google and have gotten everything from 26 psi - 60 psi. I have no clue whats best to run at this point for on road psi. Any help is greatly appreciated!

36 is for the factory stock tires listed on the door sticker as well .. once you change tires (sizes, etc.), that sticker means "nothing" .. If you are hauling stuff, I'd run 45-60 myself. That is what we tend to set the 2500s to when they come in for service with those tires on.

 

[troymi]

Thread has been a little quiet, but here's a twist:
My OE Rebel is the Duratrac LT275/70/18 and 55F/45R recommend. I'm going to use another OE wheel/tire set that is the 275/55/20 from the Off Road Group (Falken all terrain tires 113T) for some highway comfort evaluation compared to the Duratrac.

If i use the calculators, the other OE tires don't meet the load capacity?? Is that possible? I have doubts. So, if I go with 38F/36R on the Falken's I wouldn't expect any issues. No heavy load. Any thoughts?

 

[Dookie]

I run the same tires except in 22's and I have mine at 40psi in front and 35psi in rear trying to get the best/softest ride possible. I started at 50/40 and aired down and it made a noticeable difference in rides quality without ill effect on tire wear.

 

[troymi]

I run the same tires except in 22's and I have mine at 40psi in front and 35psi in rear trying to get the best/softest ride possible. I started at 50/40 and aired down and it made a noticeable difference in rides quality without ill effect on tire wear.

Thanks, I'll probably adjust to 40F/36R and see what it feels like. I was just confused why these tires would be rated "unacceptable" using the tire pressure calcs. I can't imagine the Rebel has any different requirements than Laramie/Limiteds.

 

[NJC1684]

Thread has been a little quiet, but here's a twist:
My OE Rebel is the Duratrac LT275/70/18 and 55F/45R recommend. I'm going to use another OE wheel/tire set that is the 275/55/20 from the Off Road Group (Falken all terrain tires 113T) for some highway comfort evaluation compared to the Duratrac.

If i use the calculators, the other OE tires don't meet the load capacity?? Is that possible? I have doubts. So, if I go with 38F/36R on the Falken's I wouldn't expect any issues. No heavy load. Any thoughts?

The replacement setup may throw warnings for being underinflated.

 

[Eltaco]

Thread has been a little quiet, but here's a twist:
My OE Rebel is the Duratrac LT275/70/18 and 55F/45R recommend. I'm going to use another OE wheel/tire set that is the 275/55/20 from the Off Road Group (Falken all terrain tires 113T) for some highway comfort evaluation compared to the Duratrac.

If i use the calculators, the other OE tires don't meet the load capacity?? Is that possible? I have doubts. So, if I go with 38F/36R on the Falken's I wouldn't expect any issues. No heavy load. Any thoughts?

I made the opposite swap. My truck came stock with Falkens and my tire pressure sticker says to run 32F/32R. I can’t make any sense of the pressure recommendation difference between those two wheel setups, but I can tell you that was the factory spec with the wheels you’re now running.

 

[SpeedyV]

Thread has been a little quiet, but here's a twist:
My OE Rebel is the Duratrac LT275/70/18 and 55F/45R recommend. I'm going to use another OE wheel/tire set that is the 275/55/20 from the Off Road Group (Falken all terrain tires 113T) for some highway comfort evaluation compared to the Duratrac.

If i use the calculators, the other OE tires don't meet the load capacity?? Is that possible? I have doubts. So, if I go with 38F/36R on the Falken's I wouldn't expect any issues. No heavy load. Any thoughts?

I typically run 38 in my OE Falkens, but my truck’s a heavy one (1,069 payload). 32 (per door sticker) might be good off road, but it’s a little too soft in turns and doesn’t help with fuel economy.

 

[troymi]

Thanks to all for the comments. I ended up at 37/37 for starters and the ride quality was great. Got to feel dry highway and crazy rain and all was good. Compared to the Duratracs? Ha, I'll save those for winter!

 

[moonoil]

I just changed the 20's off my 2020 Limited diesel for factory sport 22's. Could someone please post a pic of the information placard on the doorjamb from a truck with the 22's from the factory?

 

[Alxmlr789]

I just changed the 20's off my 2020 Limited diesel for factory sport 22's. Could someone please post a pic of the information placard on the doorjamb from a truck with the 22's from the factory?

sure, what size tire?

 

[moonoil]

sure, what size tire?

285/45R22. My truck came with the 20's and my tire pressure information sticker is for them. I think the sicker for the 22's is different and wanted to find out.

 

[Grouper]

...Could someone please post a pic of the information placard on the doorjamb from a truck with the 285/45R22's from the factory?

I just swapped the factory 20's for Continental TerrainContact A/T's in the stock 285/45R22 size. The tire itself indicates max inflation 51 PSI.

The pressure calculator posted above calculates a recommended pressure of 35 PSI.

What's the placarded (door jamb decal) pressure for the OE 285/45R22 tires?

EDIT: Saw this posted earlier:

In short, look at your OEM tire size and pressure on the door. For me it was 285/45/22 @ 36 PSI

 

[Alxmlr789]

If the tire size calculator is correct above, i stand corrected. I was not taking in to consideration that the OEM sizes drop by 10%. My 25/45/22XL switched to a 35x12.5 should be @38psi i will try 40 today and see how it goes. Thanks for posting that PSI calculator Grouper