Join Date: Dec 2008
Location: Tyler, TX
Thanked 407 Times in 347 Posts
Yes, speed plays a HUGE role in MPG.
The formula for aero drag is: 0.5 x (frontal area) x V^2
Or 1/2 the frontal area times the velocity squared. So if you increase from 55 mph to 70 mph the drag increases 62%, and from 70 to 80 MPH it increases another 31%. The total drag increase from 55 to 80 is 111%!!
'93 F-250 HD, 7.3L IDI, 5spd - FARM TRUCK
I Support: Trailer brakes an every axle over the towing vehicle's GVW; CDLs for RVers; Safety inspections for ALL vehicles and 6 axle trucks (97K GVW proposal).
Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote - Benjamin Franklin
I vote for LIBERTY!