avoiding engine idle

**jtan** · January 9th, 2010 07:25 PM

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** · January 9th, 2010 07:46 PM

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

**oj88** · January 9th, 2010 09:07 PM

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** · January 9th, 2010 09:15 PM

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** · January 13th, 2010 03:05 AM

Originally Posted by 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)

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

**jtan** · January 13th, 2010 03:07 AM

Originally Posted by 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.

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** · January 13th, 2010 09:05 AM

^ 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** · January 13th, 2010 09:21 AM

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

9101:thatsit:

**niky** · January 13th, 2010 09:54 AM

Originally Posted by 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.

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** · January 14th, 2010 10:06 AM

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.