Idling vs Turning Off the Engine [Merged]

[Mguy]

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

Really? Was there a study about this?

[boybi]

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

nabasa ko din ito a very long time ago, college pa ako nun. hindi ko lang maalala kung for carbureted or efi engines. bago palang kasi ang efi nun.

[buknoy2002]

for me cguro leave engine on, pero turn off aircon

[dx8976]

thanks for the link bogeyman.
since mostly diesel ang gamit ko ngayon, then the cost to wear and tear should be even less. will have to check on the turbo though.
2 mins idling = fuel used to start? baka naman dati pa yun kung noon pang college si boybi when he read about it. is it still applicable today?

[boybi]

2 mins idling = fuel used to start? baka naman dati pa yun kung noon pang college si boybi when he read about it. is it still applicable today?

hehe, parang sobrang tanda ko na dyan sa statement mo a early to mid 90s ko lang nabasa yan.

[oldblue]

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?

mahirap mag-turn off ng engine or even aircon pag nasa traffic, very hazardous sa health mo. sigurado langhap mo lahat ng poisonous gases ng ibang vehicles. so it's up to you kung ano ang priority mo, health mo o kotse mo.

[j_avonni]

Pag nasa traffic, keep it running kasi you wouldn't know kung mag-go na. but, if you're just waiting for more than 3 minutes, better turn it off - depends also on the situation - heat, maalikabok, usok, safety in the area.

[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.

[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.

[jonvic]

yung 2 minutes idling po ba applies to diesel also?

madalas kasi pag nagsusundo ako kay misis nag-aantay pa ako, sometimes lumalabas agad siya.. sometimes nag-aantay pa ako ng ilang minutes..

would it be advisable for me to turn off the engine kung mga 5 minutes wait time lang?

Also, I read somewhere na matipid ang konsumo ng diesel sa idling so very minimal lang daw ang kain niya ng fuel.. how true is this?

[jim]

depends on the situation. pag ako naiiwan sa sasakyan then idling kasi naka on ang A/C. pag misis at mga anak ko naiiwan sa sasakyan then the same. pag kamag-anak yung hindi immediate ha or friends, turn-off engine hehehehehe. di naman kasi sila marunong magbigay ng pang-gas

[acenie]

Sa traffic hindi mo naman alam kung mag-go na and kung naka A/C ka tapos shut off engine iinit ulit, masmaganda not to shut off engine.

[jtdc]

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

is this true also for hot restarts (the opposite of cold start)... let's say you know you'd be taking a long stop (more than 2 mins), but you'd be running again in such a time the engine temp hasn't really cooled down (still within optimum operating temp) ?

[XTO]

during traffic no, kawawa starter. waiting is a case to case basis. if i know that it will take some time and it's safe or not hot outside (say 5 or more mins) i'd rather turn it off and wait outside.

[JAYarc]

my 400cc/.4L bike consume 10ml/minute idle *1200rpm, now imagine 1.6L engine how it gurggle fuel at rest + w/ aircon ..>>