[Jason92Classic]

I consider myself a good engineer, but sometimes things take a while for me to figure, especially if it's a project that I'm not concentrating on... like why my gas mileage is just below average.

I think about this every now and then (like when I fill up) and it seems like my mileage sucks! Usually I chalk it up to:
1. I hammer on it a lot
2. I am usually speeding
3. At least once a weekend a Honduh Riceboy gets a lesson or 2 from me
4. Sometimes I dont fill the car up ALL the way
5. I drive in traffic a pretty good deal
6. I drive short distances

Then last night it hit me! On SE-R.net they have a spreadsheet of the speed variability of changing your wheels. The classic stock wheel is a 185/60r14. I have a 205/45r16. I'm going to go crunch some numbers now and see if that is why my mileage is different. Physically, if a larger diameter wheel/tire is on a car calibrated for a smaller diameter, then you should travel FURTHER than the stated mileage!

What do ya'll think?

 

[lance]

Sure- a larger diameter tire will mean you're speedometer & odometer are showing lower results. You've actually gone further on a tank of gas than your odometer indicates. I check my mileage at each fill up and I range from 24 mpg (hard driving in winter) to 37 mpg (highway in summer). I've cleared 400+ miles on a tank many times with highway driving.

 

[Jason92Classic]

wow, that's impressive... the best I've done is just a tick over 300 miles on a tank...

 

[lance]

I used to go 40K per year, mostly highway, and cleared 100K two days shy of 2 1/2 years. 75 mph on cruise control (I have a '94 SE-R) in warm weather will net fantastic mileage. I have 175K on it now and it still has the original clutch & exhaust system. Don't think it's babied, though- it sees 6 grand every day and I rarely shift with the clutch (usually in/out of 1st). I go through front brake pads like socks.

 

[Ben]

Best I ever did was last week- 370 miles to a tank