Date: Thu, 13 May 2004 15:50:56 -0700
From: Ben Dorfan <ndorfan@domain.elided>
Subject: [alfa] RE: Fuel Economy vs. RPM
I was reading Pat Braden's AR owner's bible and I found something that
might ressurect the fuel economy vs. RPM discussion. This was in a
previous post on the subject:
//
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...
//
For cars equipped with Bosch Jetronic EFI, full open throttle triggers
the full-throttle switch that activates what Braden describes as a
"damn-the-torpedoes mode. (pg 48)" The injectors fire twice (instead of
once) per 4 revolutions, and the oxygen sensor reading is ignored,
allowing a richer than normal mixture. This leads me to believe that,
while close to wide open throttle (as described above) may be most
efficient, "floored" full throttle throws economy out the window.
Ben
87 Spider