Tire pressure (psi) for best tire durability and MPG.

They should be what is stated in the manual for your tire type when cold. Once they heat up they would be in the 34-35psi range. It's really important to run the correct pressure in the winter according to the vehicles GVWR (and that pressure is in the door sill) to prevent hydroplaning and get the best tire to road contact.

 

I run my BFG KO2's E rated 265/75/16 at 35psi

 

I agree. Let me add that anything around the tire pressure recommendation will not make much diffence but you should add some with loads. Anything up to 35 lbs is fine if it's cold weather in the winter ss sudden temp drops can take a few pounds out. So in the summer for general driving, I keep the 32lbs, for loads and/ or cold weather, 35 lbs. This is for OEM size tires.

These are always COLD pressures so in hot weather, expect them to be higher later in the day. Don't take air out if a hot tire is 36 lbs and when it's cold, it is 32 lbs. it's the cold temp that you measure the tire by.

 

When I bought my truck in October they were filled to 28 PSI. I haven't touched them since. Wouldn't they come from dealer with correct PSI?

 

Sometimes the dealer doesn't pay enough attention. What's the number on the driver's door?

 

Sometimes the dealer doesn't pay enough attention. What's the number on the driver's door?

 

In short, no.

Im one who always follows the door sticker recommendations, and usually run stock size. Mine are constantly over inflated by 5-7 psi if it goes into the dealer for something.

 

The sticker on the door jamb is all about the tires that came on the truck....This info can be totally useless if you change brands or sizes.....and especially worthless if you switch to a different style of tire.

If I ran the "door jamb" pressures in my 265/75/r16 Duratracs, they'd shake my eyeballs out.....Even at 35 psi, they had a BAD vibration in all 4. Balancing didn't fix that. They were balanced PERFECT. What it took was 38 to 40 psi. THEN they rode smoother'n I'd ever imagined a more aggressive tread pattern was capable of. Low PSI (Below 35) and the gas mileage dropped by more than 5mpg from stock rubber. With 38, I'm getting north of 20 most of the time. Chalk test (@ 38psi) showed less than 1/4" at the very edges of the tread NOT making full contact . Tires are wearing great, ride VERY smooth, the truck handles well, and I'm getting good mileage......with psi well ABOVE what's "on the door".

Just for the record, I ran 'em @ 30psi for ONE DAY.....I probably still owe someone for gas I used that day. Mileage SUCKED. Truck rode like I was driving on a water bed. And the tires were their noisiest. Not to mention all the vibration.....

 

When I turned on my truck this morning the PSI read 25, after about 20 mins of driving it climbed to 28. Should I fill my tires to 29 first thing in the AM before driving it?

 

At a minimum, yes. I inflated to 35 cold and increased my mpg by about 1/2 mpg. I like the ride better but it's a personal choice.

 

This is true!

 

Here is a good bit of info on temp/pressure. 2-4 psi over will help from being underinflated due to bleed-off which is way worse and more dangerous than being a few psi over which has no negatives. Somebody did a study (can't remember who) and showed that most people don't check often enough and wind up chronically under due to bleed-off.

Tires sidewall is not a recommended pressure, nor is it the max that the tire will safely hold. It is the pressure required to carry max load of the tire.

The range of slop is several PSI as far as tire wear and general performance, but being significantly over (for a given use case) will cause wear issues, rougher ride, and significantly under can cause wear, heat, and potential danger of failure problems.

 

Just checked my receipt from discount tire when I had new BFG KO2's installed a couple weeks ago. 35 in the front 40 in the rear. Maybe lower the pressure in the rear abit?

 

That's pretty low pressure for E1 tires, but that's just me.

 

Im running the stock tires still on my sport. Door says 29psi, I have 30 cold… wondering if I should bump it up a few!

 

I was at the toyota dealer last night and the service manager said here in Salt Lake City during the winter months they recommend having them filled to 38psi and that is what they set them at during service between Nov-March months and 34psi Summer months.

 

That's so they cut through the snow better. Not very good for the tire but won't kill it.

 

Rear tires should have less pressure than fronts when the engine is in the front

 

Only on some vehicles Eric!