[NachtRitter]

Originally Posted by Old Tele man

...this Car-and-Driver article has some rather interesting information about GM products that eco-drivers might want to know:

When Coasting to a Stop, do Not Shift Into Neutral - Feature - Car and Driver

The article just talks about DFCO, which is not unique to GM vehicles. Makes perfect sense; if you've got to slow down anyway, might as well slow down without using any fuel at all. That could be done by shutting off the engine, or by leaving the car in gear so that the engine is forced to rev higher than the fuel cutoff point. If you take it out of gear with the engine running the engine *must* use fuel in order to keep running. Not much, but more than none.

Old Mechanic described it perfectly:

While DFCO gets me infinite mileage, coasting at 64 MPH with the engine running gets me 240 MPG during the coast, and that would last a whole lot longer in neutral than in gear using DFCO.

When I'm sure I've got to stop anyway, I will leave the car in gear. When I don't expect I've got to stop, I'll take it out... even though it uses a small amount of fuel, I'll get a lot farther.