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Old 06-18-2008, 06:46 PM   #1 (permalink)
beatr911
Master EcoModder
 
Join Date: Feb 2008
Location: West Coast, USA
Posts: 516

B2300 - '96 Mazda B2300 SE

Focus - '05 Ford Focus ST

The red car - '00 Honda Insight
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Disengaging auto trans for coast.

Our '02 Honda Odyssey FSP leaves the transmission engaged when decelerating. On one hand this may be good for MPG by enabling fuel cut when coasting above 1500rpm (per the manual) but keeping the engine speed up to enable fuel cut really reduces the length of the coast. Manual vehicles can use engine on coast to a greater benefit that those with automatics because of total disengage.

Many GM auto trannies (and I'm sure others as well) disengage when coasting at almost all speeds. This feature I like, it enables longer and more consistent coasts rather than decelerating though all the downshifts to keep the RPMs up and enabling fuel cut.

So, anyone know how I can enable disengage when coasting? I'd guess it is a PCM module modification somehow.

P.S. Using neutral makes me really nervous, there is a distinct zzzip sound of grinding gears when shifting to Drive when in motion. A replacement $2000 transmission can buy 500 gallons of $4 gas, and is a lot more hassle.

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