Tire Pressure Question

[TonyMazz]

I am curious about tire pressure....

 

I have an 04' Tahoe LS and am running the factory Firestone Wilderness LE's 265/70R16..

 

The Door sticker says I should run the pressure at 35PSI cold and the tire says max 44 PSI cold.

 

As the tire heats up, pressure goes up, I assume about 3-5 PSI ? Since I primarily do highway driving (90% Hiway 10% city) no heavy load, no off road...what do you recommend ?

 

Stay with the door sticker or run 40 PSI ....???

 

While I now the ride will suffer abit with harder tires but gas MPG will improve as well...right ?

[GM-Tech]

Personally, I'd stick with what's called for. I don't think a few psi is going to give you a noticeable increase in mpg. You could always try it and let us know.

[blue2kzr2]

If I may add some clarification to GM-Tech's post. Use what is on the sticker in the door, that pressure is what is suggested based on the "typical" loading of the vehicle. The pressure molded into the sidewall of the tire is the max pressure the tire can take. Since the tire can be on any of a number of vehicles there is no way the tire manufacturer can suggest a pressure.

 

The "best" way to find the pressure that's best for you (if you think you're running too high a pressure) is to drive over damp road with your typical loading (not through puddles, just a damp road), if the outer edge of the tire stays dry, drop the pressure.

[TonyMazz]

...well here is info from Firestone.....

 

Inflation Pressure

Proper inflation pressure is essential for achieving maximum performance and mileage. Improper tire inflation pressure can cause severe internal tire damage, which can lead to sudden tire failure and resulting in serious personal injury or death.Improper inflation pressure may result in rapid or irregular wear. Pressures should always be checked when the tires are cold and at least monthly. Under normal tire operation, approximately 1psi of tire pressure will escape every month. Also, for every 10 degrees F change in ambient temperature, tire pressure will change by approximately 1psi.

 

Vehicle manufacturers list recommended tire pressures for original vehicle tires in the owner's manual or on a placard on the end of the driver's side door or in the glove box.

 

For continuous high speed driving, tire pressures should be increased by 3 to 5psi above the normal cold inflation recommended.

 

However, for passenger tires, never exceed the maximum inflation pressure molded on the sidewall. The inflation pressure for light truck tires may exceed that molded on the tire by 10psi. Any recommended front to rear pressure differential should be maintained.

Recommended Inflation Pressure

Many people ask "what air pressures do you (meaning tire companies) recommend for cars under normal conditions?" The answer is "we recommend what the vehicle manufacturer recommends."

 

 

What criteria do the car manufacturers use to determine inflation recommendations

* Ride

* Load capacity

* Traction, wear

* Fuel economy/Rolling resistance

 

.....are all correct. But, consider another question: "Why did Ford recommend 30 in the front and 34 in the rear on a 1997 Crown Victoria?"

 

The additional air stiffens the sidewall and makes it more stable. In order to achieve the handling, tracking, and other driving characteristics, one of the things the manufacturer can do is balance front to rear handling by adjusting the tire pressures. In adding the same air pressure in the front as the rear you will change the handling characteristics from what the manufacturer intended. Quite a few station wagons and light trucks have different pressures for the front and rear. But, it's not just station wagons and light trucks; it's also Porsches, Nissans, Corvettes, Hondas, and BMW's to name just a few.

 

 

Click here for a graphical demonstration of how to check your air pressure