Quote:
Originally Posted by 88Z-Man
Al, does Demand/Active Fuel Management actually work? I have heard nothing about it making any kind of difference. I know it was a failure in 80. Of course now the electonics and computers are better.
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It depends. If you are stop and go, it wont do much. If you drive highway, then yes it will. Everyone who reviews the GM system says its seemless and you cannot tell when the engine goes into 4cyl mode.
The 8-6-4 system as a great idea, but did not have the computing power that modern ECM's have.
Yes it does work, and does a great job.
GM has AFM on several cars and trucks that are equiped with V8's.
GM also uses it as part of its 2-Mode advanced hyrbid set up.
Mode one is electric motors power truck around town
Mode two is at highway speed, the 4 cyls shut down and electric motors can assist in pushing the car foward instead of reactiviating the other 4cyls, to continue to get better gas milage.
Does it work? City EPA numbers of a Tahoe Hyrbid are the same to that of a 4 cyl Toyota Camry non hybrid. Not too shabby for a big SUV that holds 8.
Chrysler and Honda both use a similar technology. Chrysler calls it Multiple Displacement System and Honda have Variable Displacement system. MDS is available on the Hemi V8 in truck and cars with the 5.7.
VDS in Honda's can go from 6 to 4 to 3 depending on need. Recent reports have shown that its not a smooth and there is a noticable shudder when driving the Honda system.