Tires, my secret sauce formula.

[SVOboy]

It's too bad coke keeps losing money while pepsi's profits shoot sky high, but then again I hate coke's politics and think pepsi tastes better, so w00t.

[Compaq888]

Originally Posted by SVOboy

It's too bad coke keeps losing money while pepsi's profits shoot sky high, but then again I hate coke's politics and think pepsi tastes better, so w00t.

umm coke is pepsi, and so is sprite. It's one big monopoly.

[Compaq888]

Originally Posted by krousdb

I have done extensive testing under controlled conditions with the Prius and the difference between 35 PSI and 60 PSI was only 2.5%. In your case that would be 1 MPG. I have noticed a 3-5 MPG increase due to switching to smaller, lighter wheels with smaller, lighter LRR tires,

Compaq, I am dumbfounded by your results. A 33% increase in FE, IMHO, cannot be explained by a change in tire pressure alone, unless your tires were at 10PSI to begin with.

I can't explain it either but the more my tire pressure is the more mpg. I'm at 50psi now and my gas gauge hit 3/4 mark at 80 miles. With 55psi it hits at 90 miles. With 30 psi it hits at about 70-75 miles.

[thisisntjared]

your methodology sucks. calculating at the pump with the odometer works guessing with your gas gauge is crap

[Matt Timion]

Originally Posted by thisisntjared

your methodology sucks. calculating at the pump with the odometer works guessing with your gas gauge is crap

True.

Making "on the fly" assessments is never scientific. If you want to compare 35psi vs. 50psi, you'll have to run a tank or two of each and compare the results.

Of course, everything else will have to remain constant.

[GasSavers_Randy]

I think rolldown testing is how to measure this. On a flat stretch with no cars you take your car out of gear and let it coast down. If you know the weight of the car and how fast it slows down you'll know how much energy is lost, with no engine stuff getting in the way. This would be great for tire PSI, because it's so fast. The major problem is recording your speed vs time.

[Compaq888]

Originally Posted by thisisntjared

your methodology sucks. calculating at the pump with the odometer works guessing with your gas gauge is crap

my methology may suck but the fuel receit doesn't lie. I got 24mpg on 30 psi and I'm getting 30mpg on 55psi.

[SVOboy]

It seems that the fuel receipt for 55 psi doesn't seem to exist yet.

[Matt Timion]

Originally Posted by Compaq888

my methology may suck but the fuel receit doesn't lie. I got 24mpg on 30 psi and I'm getting 30mpg on 55psi.

Uhm, think about what you just said. if your methodology sucks then your fuel receipt doesn't mean anything. The accuracy of your results is determined by the methodology used.

Maybe it's time to conduct another overinflation experiment, gassavers style.

[thisisntjared]

the receipt does lie, you can over or under fill a tank up to one gallon. that leaves a lot of margin for error.

the only way you can weed out this error is to consume a lot more gas to make the difference insigificant.

i guess the radiology guys dont have to take statistics...