Originally Posted by dundee23
my i6 is getting 15mpg average- highway 20mpg keeping it 65 at 2000rpm's,,,, mine just cost $80 to fill up. since gas went up i have to drive my wifes accord 3 days a week
My tires may be *slightly* smaller than stock, which would cause my numbers to be mildly inflated due to my odomiter counting more miles than factual, and me driving a bit slower.
I found my highway millage between 60-65 to be amazingly different. At 60 its 25mpg, and at 65 its 21mpg. (Or so, and not as well documented by me) If I was to drop it down to 55 I think it would get better, but the speed limit is 70 through most of my trip.
Think on this, I will use my 300 mile round trip to and from my woman's university as an example.
300 miles, 70mph, 19mpg (Just as an example)
4.2 hours, 15.7 gallons burned, $4 a gallon thats $63.15.
300 miles, 65mph, 21mpg
4.6 hours, 14.3 gallons burned, $57.14. You loose 4/10th of one hour, or 24 mins and save $6.
300 miles, 60mpg, 24mpg
5 hours, 12.5 gallons burned, $50. (Compared to 70mph) Lost 48 mins, saved $13.15.
As you go faster your fuel economy drops like a rock. I believe the most fuel efficient speed for my Jeep is 48-51ish. Speeding to work? This is over 300 miles! On your short drive speeding doesn't save you as much time as we like to think it does!
Now think of this though, what is your time worth? Do you have an abundance of free time and no money? Or do you work 70 hours a week and time with loved ones is precious? I value my off time at least at $12 per hour, because I am ALWAYS at work. This means that saving $13 but loosing 48 mins with my beloved woman is most likely not worth it. If I was a broke student again? I would never see 56mph.