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Re: Fuel economy (was Re: Pressure Acummulator Discoveries)

> On the topic of fuel economy, if you have an automatic expect significantly
> lesser mileage than a 5 speed of the same model/year. If I'm not mistaken,
> early Audi automatics were 3 speeds (no overdrive) -> poor mileage. A manual 5
> speed Audi has better fuel economy for two reasons - less transmission
> losses and "deceleration fuel cutoff" (shuts off injectors when the car
> is in gear, clutch not pressed and throttle closed). I know for a fact that
> the CIS equipped 86-88 turbo 5000 cars have the deceleration fuel cutoff
> feature, but I'm note sure about others.

I think this is a CIS-E feature, so it appeared on the 5-cylinders in some
applications starting in 1985.  I'm not sure if it cares whether the car
is in gear or not.  Basically it shuts off the injectors until (among other
things) the rpm's drop to a certain point.  With the clutch in or the car
in neutral, the rpms will drop almost instantly.  

> Zafer
> zm@mhcnet.att.com


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