Forester - Maximizing Fuel Mileage?

Internal combustion engines produce the most power from the least fuel at wide open throttle and lowish RPM. You therefore get the best fuel economy at cruise from having a gear so tall that the engine can only just maintain cruising speed with your foot flat. Unfortunately cars these days have far too powerful engines for that (or alternatively the engines aren't built to be able to run smoothly at full throttle and 200 RPM...).

But that best economy thing applies to acceleration just as much as to cruise. Acceleration requires producing power. That power is most efficiently generated by using a good bootfull of throttle at lowish RPM. Press hard, and shift gears early.

(Apparently nothng, because you appear to have inserted a sig. separator at the top of your reply. I'll do my best without any context.)

You ask for a source of the advice that it is better to accelerate briskly to your constant cruising speed rather than dawdle. Sorry., but I can't quote one. Try googling. The research was widely publicised, in the UK at least, several years ago. No it doesn't go against the physics, just against the perceived wisdom. Modern engines are highly efficient. They use less fuel in a brief burst of high revs than a long slog at low revs. Also, you are far less likely to delay and frustrate other motorists. And no, simply slowing down doesn't necessarily save very much fuel, if any. It is the ability to maintain a steady cruising speed on light throttle which makes the big difference. Most people drive too close, don't look far enough ahead, don't concentrate hard enough and don't anticipate well enough....consequently they are always having to slow down, then speed up again.

David Betts snipped-for-privacy@motorsport.org.uk

I recall that same advice once given by Consumer Reports - though it may have been specific to a certain model car. I dunno

Carl