just a quik question that im not sure of. if my tires say 80psi max cold what should i put them at when they are warm. i do a lot of city driving so im trying to get the best mpg i can. oh yeah 98 ram 1500 EC 5.9L 2wd

 

Nowhere near 80 psi for one.
Depends on tire size,wheel width and load.
I would put about 33-35 and watch how it is wearing and go from there.

 

I would have to disagree, the firmer the tire the better the mileage. 75 psi is what I run my tires at. they as well are rated for 80psi.

 

sweet thanks i put them @70psi. and drove around town and almost thought my gas guage was broken! before they were @40psi and a to b was 1/4 tank, and now a to b is only 1/8 tank! plus the tires look fine no weird wear marks or bubbles. rides a little ruffer now but i can deal with it. i appreciate the help.

 

To answer what I think is the original question, "cold" pressure means ambient temperature, before driving on the tires. If you have been driving on the tires before checking the pressure, you will not get an accurate reading, but if you do not exceed the max, you will be ok, because pressure rises as the temperature rises. So if the tire is max 80 psi, 80psi "hot" may be only 77psi "cold" depending on the temperature difference.

Inflating the tires to 70psi will help gas mileage, but will probably result in premature wear of the center tread.The tire balloons up when it has such high pressure, which puts more wear in the middle.

Never exceed the stated max pressure on the sidewall.

 

Tire pressure has always been a comprise. The only time you do not comprise is with the load capacity. The load stated on the tire is at the maximum pressure on the sidewall. The use of ā€œEā€ rated tires must mean you use your truck as truck. You need the proper PSI to match your gross vehicle weight.

That said, this is my procedure for over 40 years (yes, back in day of 4ply nylon bias ply tires that lasted 20,000 miles if you were lucky.) Pump the pressure to the maximum listed on the tire. The back off until you like the ride making sure you do not go lower than the vehicle manufactures recommendation. Then find a large smooth parking lot or straight stretch of road. Draw a wide chalk line across the tread of each tire. Drive for a few minutes and check the chalk lines. On any tire if the center is warn, but the chalk remains toward the edges, you have to lower the pressure as it is over inflated. If there is only chalk down the center, it is under inflated. You want the chalk to wear evenly.

Personally, I run my tires hard as I like the feel of the road, feel the steering is more responsive, running temperature is reduced, fuel mileage increases and tire longevity is increased. My current ride has 46,000 miles on these lousy Jersey roads, but I still have between 6 -7/32 on the cheap OEM Goodyears. I run 44 front, 40 rear while the label in the door jam states 35. My last 2 tire purchases were Michelin and got in excess of 100k.