Idling vs Turning Off the Engine [Merged]

[ravelcop]

While waiting in the car, when can you say that it is fuel-saving to turn-off your engine than leave it idled? Narinig ko kase sa TV na aksaya sa fuel when you keep starting your engine. Meron bang specific duration na it is better to leave it idled instead of turning it off and on back again?

[ILuvDetailing]

if you have to wait more than 5-10 mins.

[vicoyski]

If you have a turbo engine, you really need to idle for a minute or two (sometimes longer). Else, your engine might die on you, one of these days. And, that's a lot more expensive than saving on a few ml of fuel.

[mrpink]

pagnaipit ka sa buhos style na traffic ... patayin mo na makina mo .. tapos hanap ka ng nagtitinda ng mani sa labas ..

[mazdamazda]

AFAIK, the fuel consumed by turning on your engine = 2 minutes of idling your engine

so, if you are waiting for 3 minutes or more - it is best to just turn off your engine.

[empy]

AFAIK, the fuel consumed by turning on your engine = 2 minutes of idling your engine

yan din ang sabi ng mga car talk shows na naririnig ko. the only thing is, i guess it would depend on the car, right? wouldn't a hummer h2 consume more fuel at idle than a civic cx, and therefore should be shut off sooner?

[Karding]

M54, dependent nga sa type ng car.

[kiper]

kung less than 5 minutes ka lang maghihintay.. wag mo na patayin. hindi rin kasi maganda ung lagi mong iniistart ung makina..

kung 5 to 10 or more..patayin mo na para tipid gas tapos labas ka na ng kotse para di ka maiinitan at para mas safe kesa maghintay ka sa loob ng kotse.

[mazdamazda]

yan din ang sabi ng mga car talk shows na naririnig ko. the only thing is, i guess it would depend on the car, right? wouldn't a hummer h2 consume more fuel at idle than a civic cx, and therefore should be shut off sooner?

well... the h2 will also consume MORE fuel than a civic when starting it up right? ;)

[mbt]

why would a start use more fuel?

baka para sa cold starts lang yan?

i don't see how a hot start will use up more fuel... gas-electric hybrids routinely shut off the gas engine the moment zero loads are encoutnered

[orly_andico]

ang alam ko 30 seconds to 1 minute lang. pero kahit ako di ko sinusundan itong rule na ito..
mbt is right, kung cold start, buhos yung fuel. pero kung operating temp na, starting the engine will not consume an excessive amount of fuel.

[empy]

well... the h2 will also consume MORE fuel than a civic when starting it up right? ;)

true...i didn't think of that

[dx8976]

When is it better to keep the engine running as opposed to turning it off and then on? Minsan naka idle tayo sa traffic for 5-10 minutes, wouldn't it be better to turn off the engine? What negative effects would it have on the engine?

[lakay]

No adverse effect to your engine if you turn it off, specially if you are idling for that long. It actually saves you a lot of gas because you engine running with 0 mpg/kmpl. I do it all time specially if I get caught on a railroad track and the train have more than 3 engine pulling the train because it means that it long wait. But if you are in our native land or somewhere hot/humid, you have to suffer from heat/sweat.

[Bogeyman]

AFAIK, it's always ideal to keep frequent engine starts to a minimum, as engine parts are subjected to accelerated wear every time the ignition is turned on. On the other hand, you have the argument that idling the engine for too long wastes fuel.

It's one of those instances best left to judgement calls.

[dx8976]

AFAIK, it's always ideal to keep frequent engine starts to a minimum, as engine parts are subjected to wear every time the ignition is turned on. On the other hand, you have the argument that idling the engine for too long wastes fuel.

It's one of those instances best left to judgement calls.

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

lagi kasi kami nakaidle, waiting for kids, traffic, etc.
but now that fuel costs look like they're going to keep going up, it's time to rethink that...

[zero]

i rather keep it on.
madalas sa mga alternative route na lang ako kesa naka-stop ako sa kalyeng matrapik.
ex. kapag matrapik ang ortigas dun ako sa shaw or pioneer dumadaan.

[ILuvDetailing]

amount of fuel used to start = 2 mins idling, do the math

[jim]

i'd rather keep in on specially at night time. mahirap na baka may gago na mang-holdap, at least pag naka on pwede na akong umarangkada agad hehehehe

[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.