Engineering Explained: How much fuel does idling consume?

[ksa8907]

Originally Posted by ProDigit

According to my OBD scanner, my Fiesta ST with 1,6 liter turbo, idles around 0.4l/h (0.1gal/h), or 0.6l/h with the ac on (0.16gal/hr).

I'm surprised you get almost 9 times more fuel consumption at idle!
Then again, the forester has a 2 to 2.5 liter engine. The larger the engine, the higher the consumption.

Personally I wouldn't bother with start stop technology.
The engine wears out most during startup procedure, according to Shouty Kilmer:

Also, a lot of the 3.6 minutes start stop, is from the entire trip.
Many times, cars stop their engines to start them well within 1 minute. Sometimes stopping the engine, only to start it again within seconds, because that's how traffic goes.

I have never ever waited somewhere for 3.6 minutes (save for a railroad crossing with a long train passing at slow speeds, where I do turn off the engine).

The engine wear, starter wear, battery wear...
Not only the items breaking, but just one time charging labor, nullifies the savings you get on fuel.

Shouty... there's a real scientist...

[Gasoline Fumes]

Originally Posted by California98Civic

Also, I am driving a 1998 Civic that I bought in June 2001. It has 260,000 miles and still has the same rods and bearings and piston rings... same 1998 starter. But for the last 90,000 miles I have been stop/starting it maybe 10 times a day.

Just one person's experience... but I think the hardware is a lot more durable that he is claiming.

I just hit 250,000 miles on my 1991 Civic. I'm also on the original starter. I did have to replace the starter solenoid contacts, but that was before I started hypermiling. And the engine internals are original as far as I know (purchased with 75k on it). The engine rarely gets to idle, it's either doing work or it's off.

I bump start a lot too. I did a preemptive clutch disc replacement at 198,000 miles when I swapped in the HF trans. Still using the original pressure plate.

[ProDigit]

Hondas are well made.
However, I believe shouty, when he mentions about certain cars having a regular starter and started stopping technology. Almost every vehicle I know, had to have at least 1x starter exchanged in it's lifetime.

[Frank Lee]

I think many starters get replaced when all they really needed was a cheap and easy to install set of new brushes. People freak out "OH STARTER WEAR! OH STARTER WEAR! IT'S A $3000 BILL!!!"

[ProDigit]

$3k?
Starters over here is an $85 job.
Still... Not all starters need just a new set of brushes,
Some have molten coil wires, due to debris getting in, and destroying the coil insulation.

[Frank Lee]

I slightly exaggerated... but so do they.

[Grant-53]

If someone is quoting more than $300 to replace as starter get a second opinion. With 10 years in the auto parts business I'd say heat breaking down the insulation on the field coils is the most common failure mode. Before EFI the rule was not to idle more than 2 minutes.

[Xist]

Does Shouty compile data or is he just screwing around? I do not know about the engines, but these guys want you to believe that the starts are specifically designed for start-stop.

[ksa8907]

My starter is a 74hp 3-phase electric motor

[Frank Lee]

Re: start/stop systems: I see various comments online about lube specifically no oil pressure starts. They seem to equate cold starts with hot starts and there really shouldn't be much comparison as far as engine wear. They forget that an oil film stays on the moving parts. If I were to subscribe to their theory, all my splash-lube engines should fail prematurely as they NEVER get pressurized oil.