Effects of tire pressure on fuel mileage??

[tractorface]

I have been experimenting with tire pressure on both the truck and my Honda Accord. The truck mileage seems to be consistent dispite any pressure changes. The Accord does much better with more air in the tires. How does the manufacturer come up with the numbers on the door? If my door says 30 front/29 rear what is the harm of running say 38 all around since the tires say max 44. Anyone have any thoughts on this?

Thanks

 

[Mundgyver]

On my cars, I always run the Max pressure liste on the side wall of the tires. Works well and I have never had a problem.

 

[JFaughn]

This is how I understand it, the manufactuter has to pick a tire[ there are a lot of opptions for you and aftermarket, within the engineiring of the car-truck in ?] the manufacturer picks the one that makes the bottom line best, so now that your in the dession drivers seat pick a tire and go by the markings on the tire , within reason the tires ratings makes the car or truck in ? what ever your needs are, so now you have a choise to make the low side of the pressure for ride comfort, the high side for better millage or carring more weight , theres alot more to it than that but thats what most people need until they are racing or some tipe of compition.

 

[Mundgyver]

When every I have had to replace stock factory tires on any of my rigs, I have always gone one size bigger on the tire that would fit a stock rim and run the pressure listed on the side wall. I get very good wear and my mpg is always on the high side. The benifit is I get a littler taller ride and more side wall for a little more cushion/comfort and the handling gets a little better. This is the approach I have used on my current truck also. I get a nice solid 24 mpg out of my truck which is a 2001 HO SB 6 speed with 285's installed. Tire pressure is at 60 psi all the way around. As for going with really big tires, its not for me. Stock rims with on size bigger is where I get the best all around performance for what I do. If you put on a skinner/taller tire with a high pressure rating, your mpg will go up. Everybody likes the fat muscular look these days but I would venture to say it might make for an interesting test to find someone that had some time and a little money to run two different tire styles, muscular vs tall/skinney on the same rig and see what would yield the best mpg.



Food for thought