Quote:
Originally Posted by Gasoline Fumes
If you track your MPG and get consistent numbers, you can easily try EOC and see how much difference it makes. 1/2 to 3/4 mile at a time sounds worth it to me. If you can estimate the total potential coasting distance with the engine off, add that distance to your miles and recalculate a tank to see the difference.
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Good point, I'd have to do some experimentation to know for sure. One calculation I did do though assuming 5 minutes per day coasting at 0.2 GPH (typical idle fuel consumption according to my Scangauge) I could save 0.016 gallons on a 25 mile trip if I shut the engine off when coasting assuming no losses from having to restart the engine.
If I'm averaging 50 MPG (close to my best), I burn 0.5 gallons of fuel. If I saved 0.016 gallon of fuel with EOC, I would have used 0.484 gallons instead and would theoretically average 51.6 MPG assuming no losses from restarting the engine. Although 1.6 MPG is a decent gain, I would assume that real world gains would be slightly less than that due to the slight losses from having to restart the engine.
But when the increase in either starter wear from using it to restart or clutch/synchronizer/drivetrain wear from constant bump starting is considered as well as probably somewhat more wear on the engine and potential safety concerns, to me that offsets the theoretically possible 2-3% savings.