quick, if you're interested in how far off car computers are about the mpg indications, check the newest Car and Driver magazine for this informative article

editorial in this months Automobile Magazine about the window sticker, the EPA requirements, and the estimated MPG figures

real, accurate MPG numbers for my 2012 Veloster.. from me. Kia and Hyundai have been found guilty of false advertising on their numbers, but not by much

I just went round trip from San Diego to Las Vegas

I got 37 mpg at 80 miles per hour going to Las Vegas,

 and on the way back, stopped at Victorville to gas up (3.85 a gallon an exit south of the Palmdale exit which was 4.25 a gallon) and

got 39 mpg at 80 on the trip from Victorville to San Diego

The Hyundai and Kia ESTIMATES were found to be over the reality by the EPA, who seems to not actually test cars before putting their stamp on the window sticker of a new car... huh. How about that, a lazy US Government agency taking a companies word for it when reporting information. Astonishing, and I am very sarcastic.

http://www.autoblog.com/2012/11/02/hyundai-kia-admit-exaggerated-mileage-claims-will-compensate-o/

How does your speed affect your MPG? Quick easy test described here

Find a flat straight long stretch of highway, because you don't want any deviation in your cars speed.

Drive in one direction at 55 mph, then return to your start location by the other side of the highway at 65

repeat at 75 going and 85 coming back (as long as you are aware that both of these are going to attract a speeding ticket that is ridiculously expensive) if that is the normal traffic speed there (like it is here in San Diego to Los Angeles and to Las Vegas)

While doing this, wait until you get to the speed, then turn on cruise control, and zero the MPG counter

Write down what the result is after 5 or 10 miles, and after doing this at each speed you are likely to be driving at for long periods of time, you;ll know whether or not you can save a time or money by driving faster or slower based on the difference in MPG

For example, if driving at 55 gets you 35 mpg, and driving at 65 gets you 35 mpg.. you might as well drive faster and save time.

If driving at 70 or 75 gets you 38 mpg and driving at 65 gets you 40 mpg... you might consider that the difference of how much you'll pay in gas at 75 isn't very much more than you'll pay at 65, and for hundreds of miles, you'll cut an hour or two off your trip. It's going to take some math to figure out specifics... but I figure this is a good way to see what is best for your time is money, but gas is expensive long trip drives.

Fuel consumption with no equal

The above dump truck is using 3 liters of fuel a minute, and in one trip from the bottom to the top of this open pit mine, which is 10 kilometers, it burns as much fuel in that one trip as a normal passenger car uses in a year

found on Tamerlane's Thoughts http://karakullake.blogspot.com/

Fuel mileage comparison by Top Gear

The Toyota Prius gets 17.2
the M3 BMW gets 19.4

When tested at the Prius top speed around a race track, and the BMW following at the top speed the Prius could do around the racetrack.
No joke, Top Gear, Season 11 episode 1, 8 minutes into the episode.

At racing speed around a track, worst to best mileage of supercars as determined when they ran out of the one gallon of gas they were given.

Ferrari 599: 1.7 miles per gallon
Aston Martin: 2nd to run out of gas
McLaren: 3 rd to run out of gas
Lambo Murcialrgo: 4.1 mpg
Audi A8: 5 miles per gallon