list of gas saving tips from best to worst

[theholycow]

Originally Posted by Howard

Now if we could simply shut off the engine during the glide portion somehow, it would really work well. With my Subaru, I could, as it will restart by letting out the clutch, but steering is harder. Why do we need power steering on these small cars??

People have done manual steering conversions. Another option may be the electric power steering found on many modern vehicles; it's not merely an electric motor driving a common power steering pump, but rather a system that provides electric assist directly to the steering. My 2008 VW had it and steered exactly the same with the engine off as on (except it was turned off under about 3mph).

However, in a Pulse & Glide cycle, EOC isn't always very useful. It may take more fuel to restart than to idle for a few seconds, and then there's the issue of driving effort vs. payoff. It is very worthwhile for long glides and is a large part of how I did so well with the VW.

Originally Posted by Howard

On many if not most vehicles with an overdrive transmission the energy loss through the overdrive gearing is enough to cancel out any possible gains from running the engine slower. The highest gear should be direct drive, and a change in rear axle ratio should give you the RPM you want in cruise.

Interesting. I didn't know it was quite that bad. I just finished putting a 5 speed overdrive manual transmission in my 1980 Buick last fall. I wonder if I could have found a non-overdrive transmission and a ridiculously tall rear end...

Any suggestions why overdrive transmissions have become the standard for fuel economy instead of taller final drive ratios and adding lower gears?