avoiding engine idle

[jtan]

i noticed that my km/l goes down fast when engine is idle on traffic, then did some search on google:

that re-starting the engine roughly consumes fuel equivalent to 4 seconds of idle engine, so some are suggesting that when you know you're stopping in traffic for more than 10 seconds, it's best to just shut off the engine and start again when the traffic flows again

however, trade off is the extra load or wear to the starter, but some sites mentioned that restarting engines during traffic only add US$10 to your maintenance cost which greatly offset the gasoline consumed during idle in traffic

what you guys think?

[alwayz_yummy]

ok kung walang starting prob sasakyan mo......plastic parts nalang ang starters ng new cars..not recomended for that feat..

[oj88]

It's hard on the starter, starter relay and battery. You can still do it, but definitely not after just 10 seconds of idle time. Maybe if you know you'll be waiting in the car for at least 3-5 mins, it'll be a good idea to turn off the engine.

Another thing is the A/C. On a hot day, I doubt you'd last 2 minutes inside the cabin without A/C.

Hybrid cars shuts off the engine when stopped. A dedicated electric motor running off of the batteries operate the A/C compressor when the engine is not running.

[alwayz_yummy]

tama un nakalimutan ko--pag patay-buhay ka ng makina, maddrain naman baterya mo...di kasi kumkarga alternator mo....in the end di mo ma-sstart pag na-flat ang battery.. unless mechanical carburated-MT angride mo (eg. owner type jeep)

[jtan]

tama un nakalimutan ko--pag patay-buhay ka ng makina, maddrain naman baterya mo...di kasi kumkarga alternator mo....in the end di mo ma-sstart pag na-flat ang battery.. unless mechanical carburated-MT angride mo (eg. owner type jeep)

yes but it should charge when you're running unless the battery is defective

[jtan]

It's hard on the starter, starter relay and battery. You can still do it, but definitely not after just 10 seconds of idle time. Maybe if you know you'll be waiting in the car for at least 3-5 mins, it'll be a good idea to turn off the engine.

Another thing is the A/C. On a hot day, I doubt you'd last 2 minutes inside the cabin without A/C.

Hybrid cars shuts off the engine when stopped. A dedicated electric motor running off of the batteries operate the A/C compressor when the engine is not running.

yes the A/C is turned off on regular cars... i think that's the issue. but on regular car you can keep the aircon running on fan mode while there are still cool air inside.

[oj88]

^ Yes, but that doesn't solve the associated stress on your starter motor, solenoid, relay, gear teeth, flywheel teeth and battery. Not to mention repeatedly subjecting your engine to heat soak. Something's gotta give eventually and I wouldn't want to be the one scratching my head when my car fails to start at a busy intersection with a mob of angry drivers behind me.

It DEFINITELY saves gas, but at what cost?

Again, regular cars aren't designed for this, especially with the type of stop and go traffic we have here. Imagine turning off and starting your engine at least 10-20 times on your daily commute.

[CVT]

Personally, I would not recommend shutting off the engine when caught in heavy traffic....

9101:thatsit:

[niky]

^ Yes, but that doesn't solve the associated stress on your starter motor, solenoid, relay, gear teeth, flywheel teeth and battery. Not to mention repeatedly subjecting your engine to heat soak. Something's gotta give eventually and I wouldn't want to be the one scratching my head when my car fails to start at a busy intersection with a mob of angry drivers behind me.

It DEFINITELY saves gas, but at what cost?

Again, regular cars aren't designed for this, especially with the type of stop and go traffic we have here. Imagine turning off and starting your engine at least 10-20 times on your daily commute.

Heat soak happens when your engine is on inside a stationary car, with no moving air coming in the front except from the fans (which sometimes isn't enough). Turning off the engine then turning the key back to the "on" position turns the fans back on... which cools the engine bay a bit.

Yes, there is the problem of extra wear and tear on the starter... but a hot engine is much, much easier to start than a cold one, so it's not that bad.

Newer cars with start-stop functions to save fuel, though, have higher-speed starters to minimize wear.

[vinj]

If engines shut down cylinders at low load levels (like the Accord and some Chrysler HEMI engines), it would help.

But shutting down the engine and starting constantly, unless you're expecting to be idling for several minutes, is not adviseable. The wear and tear costs won't offset your fuel savings.

[oj88]

Heat soak happens when your engine is on inside a stationary car, with no moving air coming in the front except from the fans (which sometimes isn't enough). Turning off the engine then turning the key back to the "on" position turns the fans back on... which cools the engine bay a bit.

Yes, there is the problem of extra wear and tear on the starter... but a hot engine is much, much easier to start than a cold one, so it's not that bad.

Newer cars with start-stop functions to save fuel, though, have higher-speed starters to minimize wear.

An idle car has its coolant circulating and the fans blowing off the hot air from the radiator so there's little or no heat soak there (tubro intercoolers are another thing). Once you turn off the engine, the coolant stops and the residual heat on the engine block creates hot spots. On some engines, you'll hear hissing (other than the catalytic converter) of boiling coolant. Though, this happens anyway after a reasonably long drive, but what you want to achieve is to minimize this type of extreme heat cycling.

As with cars with start-stop functions, is this the hybrid? If it is, I think they don't have starters anymore. The electric motor directly coupled to the crank shaft does that. The motor is used for starting the gas engine, electric propulsion, and for charging the batteries. And since it is directly coupled, there are no gears or solenoids to wear down like those found on conventional starters.

Hybrids also have an electric water pump to circulate coolant even with the gas engine turned off. This helps prevents heatsoak, as well as providing heated air to passengers even with the engine off.