By: waltr34

waltr34 — Mon, 16 Mar 2009 15:56:50 +0000

I once rec’d with my Insurance bill some info stating the peak speed for mpg was 45mph. Because of the resistance of the air against the body of the car itself. My own test with my ’04 Honda Civic 2dr & ’98 Chevy G3500 box truck had these results. At 65mph the Civic got 34mpg & the Chevy truck got 10mpg. At 55mph the Civic got 40-41 & Chevy truck got 12-14.
I haven’t got this better mileage over the winter due to I think the winter blend of gas & the air being denser when its cold. Anyway it comes to almost 20% better mileage doing 55 vs 65.
I wonder if mythbusters or someone could take a sq. ft. of some lightweight mat’l glue it to a digital scale & attach it to the front of a car to find out how much air resistance there is per sq. ft. at a given speed. Also for automatics with a tachometer, jot down when the trans shifts into the next gear & the rpms drop on the tach. Less rpms = less gas used. If your car shifts to the next gear 3mph below the speed limit set the cruise there & save.

By: jackjack

jackjack — Sun, 30 Mar 2008 04:10:20 +0000

I was wondering how to calculate the peak efficiency speed for any car.

Comments on: How you drive can affect your gas mileage

By: waltr34

By: jackjack