Tire Inflation

For daily driving on non-OEM tires, how do you guys determine inflation pressure?

I have LT 285/70r17 tires (load class C) and on the sidewall they say max load 1250 lbs at 50 psi. The door sticker says inflate to 33 psi but that’s on stock size.

My truck is right at 5000 lbs, so divided equally (I know they’re not) that’s 1250 lbs per tire. Soooo theoretically 50 psi is the max I should go. Obviously I don’t feel like inflating right up to the max is a good idea.

So what do you guys do?

ps - Yes I’ve used the search function. It was not very helpful.

 

I use this

 

Start at the door sticker. Then do the chalk test. Make a line across the tire and drive a rotation forward. See where the line is/is not imprinted on the ground. Inflate/Deflate in 5 PSI increments until the line is defined equally across the ground.

 

I would do 35-37 and go from there.

 

This ^

 

Well for one i never install a tire much different in size than the oem ones....maybe the next size up recommended by the manufacture. Seems too many think they know more than the engineers that built the truck.

 

It’s hard these days because inflation is so high.

 

It all depends on your objective. Increased mpg, tire life, quality of ride, sand, washboards, etc…

 

C rated tires aren't really an upgrade over standard P rated tires. It's just that some sizes aren't available in a P rated tire and 285's are one of them. Use the same PSI you used before. The number on the door jamb is for best ride. The number on the tire is for when you're loaded heavy. The tires that came on the truck have 44-45 PSI stamped on them. An E rated tire is going to have 80 PSI stamped on it.

Since I don't always know when I'm going to have to throw some weight in the truck I generally split the difference for daily driving. The 35-37 PSI suggested above is about where I'd start. You can always tweak it a little if it isn't working for you. If you NEED 50 PSI in the tires the truck is way overloaded.

 

So I put out my big boy pants on and with my setup I'm running 315/75/16 . With my front bumper and winch I run about 35 psi cold in front and with no weight in the rear I have them about 31 psi

 

Trouble was when my tires were set at 35-36 psi from the dealer, the ride when empty was terrible, very jittery. Dropping the air pressure to 32psi was much better. At 35-36 unloaded your going to see the center of the tire wear faster. I guess if you carry 500 lbs of chit around with you all day running higher air pressure is ok.

 

That calculator tells me I should run at 26psi. Seems to be based on load capacity above anything else. My tread life and mpg would suffer drastically if I went that low. Think I'll stick with the chalk test and 13 years experience with the size tires I am running. P285/70R17 at 32 psi front and 30psi rear.

 

Generally its called for a couple more psi in the rear tires on these trucks. 26 psi imo, is on the low side.

 

Why more psi in the rear? There's no weight in the back unless you are carrying a load. Sticker on the door jam says same psi front and rear stock.

 

89.

 

All my past toyota trucks had higher psi by the manufacture for the rear for that reason you'd be carrying some weight in the bed or towing. I guess if your always empty or just have a grocery getter thats fine to.

 

stock vs upgraded/modded. Vehicles are made for the general public to drive on paved public roads, even my "offroad" 4x4 isn't meant to jump hills...btw...engineers developed all the performance mod parts people put on to enhance their vehicle

 

Im rocking the wildpeak P265/75/R16 at 37 PSI cold. Freeway driving brings it up to about 40 once hot Its been fantastic. Used to rock 29-30 and it just felt slow to accelerate and bogged down.

 

That looks like a typo - what tires are they? KO2s in that size can support 2755 lbs at 50 PSI.


Even the stock Firestone Destination LE2s that came on my 4-cylinder SR can do 2271 lbs @ 44 PSI.



I just switched them out for Destination X/Ts in 245/75-16 (E-load) and Costco set them to 45 PSI (stock pressure 32). The tire calculator site recommends 44 so that works out.


Destination X/Ts for reference

 

Well good for those engineers. I'm not into beating up these trucks doing any serious off-road excursions...their too nice. Long as i can get in, and out year round off the crappy road i'm on, and get to some remote fishing spots, all is good. This truck stock is better than my tundra ever was in mud, and snow. Seems most of the vehicles around here are awd, or 4wd, and do just fine stock. I'm getting to think tw is more about how many mods these truck can have, rather than owners with stock taco's just enjoying their trucks for what they are.