15 more PSI = 7% better MPG

[wdb]

Originally Posted by MetroMPG

It's not a given that pressure higher than placard = increased center wear. Depends on the car, depends on the tire. It hasn't happened to me on 3 different cars, 3 different tires.

Adding another one to the count; I ran at least 10psi over the manufacturer recommended 32psi, up to and including max sidewall (51 psi), in the OEM tires on my Fit, and they wore evenly.

[gone7]

What was the weight? Was the vehicle carrying more than stock?

[Aero]

Originally Posted by niky

Depends on the car, depends on the tire.

On my R-Comp Advans, which are wide, sticky and have a treadwear rating of somewhere between "zero" and "negative infinity", running over 35 psi... yes... friggin' 35... will wear down the center blocks quickly unless you drove it like you stole it and exit each corner at 1g lateral.

-

On my truck and CR-V, we run 45 to 50 with absolutely no problem.

Thanks for clarifying! That makes sense.

[wdb]

Originally Posted by ACEV

What was the weight? Was the vehicle carrying more than stock?

Were you asking me? I dunno, a fit weighs around 2500 lbs or so. I never carry any animals in it beyond the occasional cat to/from the vet. I've used it to carry humans, and a remarkably large amount of non-living stuff as well.

[California98Civic]

Originally Posted by wdb

...I never carry any animals in it beyond the occasional cat to/from the vet....

Some cats get heavy.

[gone7]

@wdb, Yes I was, as well as anyone else with over-inflated tires. The issue I wonder about is whether or not some might have more weight than stock or carry more as rule. That would make increased tire pressure necessary, and not considered as over-inflated at all. Therefore, tire wear would be even automatically.

There are many times we might need to carry larger loads and increase the tire pressure, or need increased traction for a short way and decrease the tire pressure accordingly.

I would like everyone to mention their loads when discussing increased pressure.

[mcrews]

it's an eco forum......nobody is pumping up to carry a 'load'. in fact the real question is "who has lightened their car weight?"

I for one reduced the wieght on theQ45 about 100 lbs.
The only time I add weight was when traveling to texas 3 times a year for a 2-3 week stay.

[gone7]

Not really. The purpose of getting better fuel economy must be coupled with getting useful work done. (The best fuel economy is probably a human-powered bicycle or similar. And that would be pretty useless work.)

If anyone is trying to get better economy, and he is driving by himself in a vehicle with more than one passenger space, he does not understand the concept of real energy savings to begin with. We are then just playing around with little bits and pieces of the puzzle. Interesting maybe, but not particularly helpful over all.

After all, don't people go to a lot of extra work to make their cars more aerodynamic? That just usually adds weight. It would be far better to shrink or expand the vehicle based upon space needed.

If one is not going to do that, then calculations of weight when adjusting tire pressure are a very reasonable part of the formula. Today I might just be driving myself, but tomorrow I might be taking the family and a full car of vacation stuff on a very long trip.

We can no more ignore weight then we can aerodynamics or rolling resistance or time or speed or any other part of the equation. Weight will always play a part in the whole discussion; especially when considerations of tire wear are concerned.

BTW, it is actually an eco-mod forum.

[wdb]

Originally Posted by ACEV

Today I might just be driving myself, but tomorrow I might be taking the family and a full car of vacation stuff on a very long trip.

In any of those cases I would be running the same pressure in my tires.

Higher pressure (up to a point) = better fuel economy. The fact that I might also desire higher pressures when carrying a heavy load is, at best, secondary to my decision.

In addition, based on the experiences, links, and other information presented on this forum, I personally have come to the conclusion that higher tire pressure and uneven tire wear are largely unrelated. You are of course welcome to believe as you will, but you should be aware that folks here place a lot more faith in evidence than than they do in conjecture.

[gone7]

Many posts are based on personal conjecture without scientific proof. In addition, there is a lot of anecdotal evidence. As such, there are no scientific conclusions to be made.

Actually, scientific evidence can be based upon the overwhelming weight of evidence, and that evidence clearly shows the over-inflation, just like under-inflation, causes uneven tire wear over the life of the tire. There is absolutely no evidence to the contrary.

BTW, I use no beliefs; I use facts.