chevy2

This.
I got 41 mpg @ 65 mph over 150 miles, including some small town driving. No wind.
With a strong headwind/crosswind, 35.8 mpg @ 65 mph over ~ 300 miles.

At 75 mph, over ~600 miles, average 32.9 mpg including a couple pit stops. Light to no breeze.

No passengers and not a lot of crap in the car. OEM tires, no wing, no cruise control.


The maxim: aerodynamic drag increases exponentially with increases in velocity over 55 mph.
The reality: it certainly does.

umrdyldo

iTrader: (1)

Yes if your exponential is 2.

Drag force equation has velocity squared.

So double your speed, quadruple your drag force.

So 65mph is 8% faster than 60 but 17% more drag force.

BPacak

umrdyldo

iTrader: (1)

http://en.wikipedia.org/wiki/Drag_equation

alerosaint

o_O......umm ok...well i been getting ~25mpg mixed highway (with traffic) and city...not to shabby especially since I get in boost quite often not max boost though

SuperSquirrel

iTrader: (1)

I was getting 26-29. Carried it to the strip last week now its averaging 18 mpg. If I reset it, that would eliminate that I am sure. But, if you think about it 18 for WOT strip runs really isnt that bad. (3 passes btw)

Terminator2

Yes because you are talking about changes in kinetic energy (eK)

eK= 1/2m(V^2)

So yes double the velocity means 4 times the kinetic energy which means 4 times the amount of friction (air drag) acting because there is no acceleration (velocity is not changing).