MPG/Range record for me!

[SilverBullet75]

Thanks Etlsport! Thought I was going nuts! (not ruling that out though)

So, with that said, what sould i multiply by to get my true MPG?

[VXorado]

By my calculation you actually got 18.96~ 19 MPG. You ODO is only slighty off and remember to use the % difference in the total miles travelled rather than the MPG. In other words you went 7.4 miles less than the ODO read.

My interstate tripped just yielded 16.6 MPG... not too bad with big tires a heavy foot

[tom4bren]

Put on 'Dweeb' hat

The circumference of your tire is the distance that your car will travel in one revolution of the tire. You can measure that by wrapping a tape measure around the tire ... or use the formula pi*radius. Radius is half of the tire diameter.

Nobody is going to go out and measure their tire circumference (probably not even their radius). They'll just use the advertised number. All you really need to remember is that the circumference is directly proportional to the diameter.

Since your speedometer & odometer are both just reading rotations of the tire, all you need to know is that if you switched to tires that are 10% larger in diameter than stock, you will be traveling farther & faster by 10% than your speedo & odo are registering.

One other thing to keep in mind is that during the life of your tires, the radius will continue to shrink (not that much on passenger car tires with a mild tread but significant in MTs and ATs). My Wrangler MTs measured 33" when new but are probably only 32" now that they are at the end of their life just due to tread wear.

Take off 'Dweeb' hat.

[WormGod]

My VX would still get 10mpg if I got out and pushed it 200 miles.

I am surprised with my STi though. I am managing almost 28mpg in that. Well, I was before the weather srtarted to cool off here, Now It's getting about 23mpg. :\