Date: Sun, 02 May 2004 10:07:52 -0600
From: C M Smith <cmsmith@domain.elided>
Subject: [alfa] Fuel economy and rpm
When BMW introduced the 528 e (the e standing for Eta, a Greek letter
having something to do with thermodynamics I believe) they did so while
advertising the results of their fuel economy testing which established
that you should drive a gasoline powered car as close to wide open throttle
as possible, at as low rpm as could be used to do the job (i e accelerate
the car) then cruise at the desired speed with the throttle as open as you
can without accelerating the car. In other words, the old jack rabbit start
so pooh poohed by the so called experts was proved to be most efficient.
Now a diesel powered car would probably be different. In fact, a turbo
diesel is so efficient in part because the diesel is not throttled.
I have found that the BMW results are correct in real world driving. I find
that using WOT or close to it in the lower gears and upshifting at
relatively low rpm gets you to cruising speed quickly and with minimum fuel
consumption.