I did not see any increase in gas mileage inflating my tires to the max pressure of 44psi. I still get around 325 to a tank which is 26-27 with something like 90% highway driving.

 

At 44psi all you're going to do it wear the center part of your tread out and decrease your traction. Proper inflation is just so the tire holds it's proper shape against the road. Anything beyond would just change the shape so the center section is making most of the contact. 34psi is what I run. It's above spec, but here in America, car companies regularly have lower pressures for a cushy ride. +2 psi should be more ideal, but I have no real evidence other than the word of a pro driver. It would be interesting to try a giant skateboard wheel on a car. It would be loud.

 

people on gas saver / hypermile forums say differently. People have claims of significant gains from running tires to the max or more. Higher pressure is supposed to equal less rolling resistance... also the truth is I've maybe seen 2 or 3 car's that really had under or over inflated wear. Does anyone have proof of say buying a brand new set of tires or used for that matter and ran the tires at max and have kept the psi there regularly and watch the tire wear over time........

but none the less the test was bogus cause I decided to lower the psi since it didn't do anything and notice my RR tire picked up a screw and was at like 15psi.

 

I guess its a trade-off between economy (perhaps a few percent over a year), tyre compound (hard or soft), wet weather performance and cornering. Here in the UK gasoline is more than $10 a gallon and a few percent makes a difference to the punishing cost of running a car, but cornering in the wet on 44 psi might cross the barrier from bliss to horror pretty rapidly....

I think its good to increase regular pressures (I usually run at about 32psi) to maybe 36-38 under full load on the motorway to make sure the tyres don't over heat when the holiday stuff is all loaded up and the kids have all their electronic stuff.

 

44psi from what? 44 may be too much to get any noticeable difference from say, 40psi... You go from 25 to 35, you'll see a difference but after a certain point, not much, then none...

 

The big deal is that there are so many ignorant people driving around with flat tires...so many so that the government mandated tpms in all vehicles 07-08 and newer.

Exactly. 40 to 44? Not a huge or probably even noticeable difference. 20 to 30-35? Huge difference.

 

Over inflation will wear the centers down where under inflation will wear the edges down. The suggested tire pressures listed in the OEM or the door jam are the recommended overall optium pressures. The max pressure listed on the tire side wall is a safety requirement required by law so that some dummy doesn't over inflate the tires and cause an accident. Also realize that as the tire heats up the pressure builds up so if you fill a cold tire it will be higher when hot. My 89 740 recommends 38psi with a full load of 5 people. I run at 33psi for comfort. I don't care about a few extra miles per gallon. We have 4 vehicles for the 2 of us so gas mileage is not a issue.

 

If the "max" pressure is on the sidewall, why do people still go to the gas station and put 90+ psi in their tires? I've always wondered that. Even when you tell them they had 90+ psi in their tires they seem to not care, EVEN when you personally take the insane amount of time it takes to let 55-60 psi out of their tire without pulling the core. I think it should be mandated that every high school kid should have to complete a basic automotive class. And every car owner should own at least one accurate tire gauge.

 

Stupid is what stupid does. Check our education rankings

 

When I first bought this car I was running 32psi, fixed a few things, was reading the owners manual and it recommends 30 in the front and 36 in the rear and was running that psi prior to 44psi on all tires. My average gas mileage is 25-27. But like I said I had a flat for ? miles so it wasn't a good test. I personally would really like to see 30mpg.