Idling vs Turning Off the Engine [Merged]

[mbt]

that "starting engine = 2 mins. idling worth of fuel" applies only when the engine is cold, i think. certainly, the "significant increase in wear and tear" from starting applies only to cold starts too, since with a just-shut-off engine, there remains a coat of oil in the piston rings.

so i think there's minimal ill effect to the engine as a result of frequent starting and would really save you a considerable amount of fuel if you idle for long periods.

to wit, gas/electric hybrids shut off and turn on the gas engine continuously in city driving.