Air Pressure in Tires

You talking on the sidewall of the tire or on the door jamb of the car?

If the tire says 44 PSI max, I got 40. Harder ride, but usually decent handling and better fuel economy.

I checked my tires and they are all different which is not shocking in the Texas heat... I am going to air them up today. Just wondered if I should go over a notch or under... I guess under is better fuel economy?

You should fill the tires according to the recommendation from the car maker, either on door jab or sometimes the glove compartment. Going one or two psi over this recommendation is fine. However, you should check your tires when cold.

The number on the tire is the highest pressure that the tire can handle. Obviously, the tire maker does not know what car or truck the tire will be on, and cannot put the pressure recommendation for that particular car or truck on the tire.

Jeff

indeed... if 4 people get in a car then that adds what? 500 to 700 pounds to the vehicle? which is a large percentage gain...

The weight of the load won't affect the pressure in the tire very much. Maybe 1 or 2% with a very big load. When I get on my bike, the tire pressure hardly changes, even thought the percentage change is much greater.

Jeff

It has to do something with that large of a gain. With that said... I will fill up to the standard the tire says to tonite. I was just wondering the safety.

Thanks for your advice..

For better fuel economy, you want a higher tire pressure. Increasing tire pressure reduces the amount of contact the sides of the tread pattern has against the road. This, in turn, reduces rolling resistance and hence the increased fuel economy. More pressure also stiffens the sidewalls and increases steering response. The downside is that the center tread wears faster as it carries more of the vehicle's load, therefore negating any cost advantage. The stiffer sidewalls also stiffen the ride. The good news is that there is some tolerance you can take advantage of without noticeable tire wear or ride degradation. I would suggest trying an increase of 2 or 3 psi first. You'd really have to experiment on what works best for you. Good luck.

I pump them up to the max on the sidewall. I never rotate my tires. My fuel eceonomy goes up, my tires wear evenly and I generally get anywhere from 60-120,000 miles from a set of tires!

Works for me!

The maker's pressures are not always right, especially if you have a different size tyre on the car. My tyres are 40mm wider on after market rims sized for the tyre, and the pressures for the factory tyres chew out mine like there is no tomorrow and the car feels heavy. I need to run about 6 psi higher then recommended to get the tyres to wear evenly and to have the car feel nimble again.

"Viperkiller"...

Mavz, this is pretty much what I was going to write and is good advice. I always run my tires harder and they seem to wear even.

One thing you can do is the chalk trick. Chalk up a heavy line across your tires and see how that line wears off. If it wears moreso on the outside then you have not enough air within. If it wears moreso in the middle then you need more air. Tomes

If the automaker's recommended pressure is 32, then I recommend 35 ~ 36 PSI for improved fuel economy and tire wear.

Wow! Both my Toyota's would be hell to drive like that.

The Supra tires max pressure is 51 pounds (Goodyear Eagle F1) but anything over 30 pounds makes even those lane dots on the freeway seem like it's going to rattle my teeth loose.

The C&C truck tires max pressure is 65 pounds (Brigestone RD-603) but when I go over 40 pounds the dual rear tires start steering the truck with a heavy load. Then it's all over the road empty even though the curb weight is 4,700 pounds. Works fine at 40 pounds either way.

Dan