I have a different method for mileage when I travel.

I've read several articles that claim the aerodynamics on cars has been at a point for several years where opening a window can create more drag than running the A/C. This is of course provided your A/C works, and it's efficient. The old York compressors maybe not.

Aero drag is the largest consumer of fuel on the highway, so keep it as clean as possible (aerodynamically speaking). Even antennas have gotten the attention of automakers in the last decade and side mirrors for their drag and effect on mileage (One good thing from CAFE).

Even a wax job can't hurt, at least you look good!

Weight matters, don't carry weight you don't need. If you open windows/roof, find out which ones create the least disturbance in the car, you can hear turbulance. I like to run the RF and LR open a crack for circulation, quiet and good turnover without significant turbulance, ... noise is energy.

Rolling resistance matters. Most of the time the harder the tire, the lower the rolling resistance. It will ride more harsh, but if you're traveling fairly smooth roads that is just a comfort thing. Really rough roads will burn more energy.

I have a forumula around here, on my other computer, I will post it if I find it, into which you can plug your Cd, frontal area, weight, etc. and see how much HP you need to maintain certain speeds. This formula makes it quite apparent that aero drag is the biggest consumer of power on the highway. Speed increases aero drag logrithmicallly, so a little more speed is a lot more drag/fuel.

The little things matter too, such as a smooth driving style, and lubrications. I believe that premium oils and lubricants are a significant factor in the efficient transfer of fuel/heat to rotating wheels, ... which oil/lubricants are best is a topic best left alone on automotive forums though.

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Gone to the dark side

- Jeff