Idling vs Turning Off the Engine [Merged]

[Bogeyman]

what parts would be subject to wear and tear? is it the same for both gas and diesel engines? does turbo have any impact

The battery and the starter motor are just two of the things subjected to wear and tear with frequent restarts. However, there's also the contention that, provided that these are in serviceable condition, there will be no adverse effects with frequent starting as the manufacturer suggests. If at all, the cost of restarting adds some $10 (PhP500++) a year to the cost of driving, money supposedly recovered several times over in fuel savings. See here.

Diesel engines, by nature, are less prone to suffer internal wear than gasoline engines because of two things:

1. Diesel engines are built to withstand higher levels of stress, since they require a high compression ratio to ignite the air/fuel mixture.

2. Diesel fuel is sprayed into the engine during the combustion cycle, which lubricates the cylinder walls, thus reducing friction.

Not sure if it has any impact on turbo, though.

[niky]

The battery and the starter motor are just two of the things subjected to wear and tear with frequent restarts. However, there's also the contention that, provided that these are in serviceable condition, there will be no adverse effects with frequent starting as the manufacturer suggests. If at all, the cost of restarting adds some $10 (PhP500++) a year to the cost of driving, money supposedly recovered several times over in fuel savings. See here.

Diesel engines, by nature, are less prone to suffer internal wear than gasoline engines because of two things:

1. Diesel engines are built to withstand higher levels of stress, since they require a high compression ratio to ignite the air/fuel mixture.

2. Diesel fuel is sprayed into the engine during the combustion cycle, which lubricates the cylinder walls, thus reducing friction.

Not sure if it has any impact on turbo, though.

If it's in stop-and-go, I think that'd be a no-no for the turbo... but if it's not long enough for the oil to cool down radically, I guess it's okay... better to just keep it on, and turn off only if you're going to be sitting for ten minutes or more.

I usually don't turn off unless I'm waiting in a parking lot or for someone who's gone to the CR at a gas station. The savings as compared to the wear and tear and the amount of gas used to start up just aren't worth it on my car.

I agree, it's always a judgement call... but in traffic, it's always better to be ready for contingencies, so I usually leave it on, damn the gas anyway.