Trivia question about fuel efficiency

[Mudcat]

How much idling does it take to burn more fuel than shutting off your engine and restarting?


a) 10 seconds
b) 1 minute
c) 3 minutes
d) 10 minutes








The answer is (a) 10 seconds. In other words, if you are going to idle for more than 10 seconds, you are better off (at least from a fuel efficiency standpoint) to shut off your engine and restart it when you are ready to go.

I did not know this. Somewhere in my younger years I got the impression that it uses quite a bit of fuel to restart an engine and unless you are going to be sitting for a good 10 minutes, it is better to just idle. And who knows? - maybe that was true back when I started driving. Cars have changed.

But with modern cars it is 10 seconds - or even less. That is of course assuming you aren't some kind of spazz who does a lot of gratuitous revving on start-up like betplom probably does.

 

[betplom]

http://oee.nrcan.gc.ca/transportation/idling/faqs.cfm?attr=8

http://www.consumerenergycenter.org/myths/idling.html

 

[AMBy]

But won't you burn through starters much longer if you are turning it off every time you get to a redlight....seems counter productive to me...

 

[reno cool]

(Mudcat)

but you don't want to fuck up your starter, drain the battery and so forth. Though those things probably don't matter for newer cars.

In your case, if you rarely drive, you better let it run as much as possible

 

[betplom]

Muddaaaay! I personally would not take car advice from an unemployed guy.

 

[UntilTheNDofTimE]

or B buy a fuel efficient car. But yes this is common knowledge to me i only use this when i know i wont be moving for 2-3 minutes, IE at a fast food joint at 4 am

 

[Mudcat]

But won't you burn through starters much longer if you are turning it off every time you get to a redlight....seems counter productive to me...

I don't know about starters but I believe there are laws in some places against shutting off your engine when waiting for a red light.

 

[Mudcat]

(Mudcat)

but you don't want to fuck up your starter, drain the battery and so forth. Though those things probably don't matter for newer cars.

In your case, if you rarely drive, you better let it run as much as possible

Yeah, could be, could be. I was just speaking specifically about fuel efficiency. Could be other factors for the sharp motorist to consider.

 

[AMBy]

fuel efficiency is overrated anyway..

 

[fiveteamer]

Amby as a young republican do you believe in the sun?

In other words, do you believe that sun does not actually exist?

 

[wal66]

Muddy you leave your car off for months at a time already, splurge a little and idle that puppy at the next red light you get caught at.

 

[Mudcat]

Yes, like so many things in life, I am the backwards case. I need to run my car just for the sake of running it.

I finally reached the 30,000 km mark last weekend. (18,750 miles). I have had it for 4.5 years.

That shit is bananas, B-A-N-A-N-A-S.

 

[RogueScholar]

While the observation about the wear on your starter and electrical system every time you start your car are valid, the real toll in turning off the engine as opposed to idling comes in the cylinders themselves. Starters and alternators are easily replaced, but the cylinder walls and piston rings are much more expensive repairs, requiring a total engine rebuild in most cases. The piston rings seal the combustion chamber, and they travel against the cylinder wall, typically lubricated by the oil circulated by your oil pump. From the second you turn the car off, the oil which was coating the cylinder walls begins to fall back into the oil pan. The greatest trauma to your cylinder lining and piston rings occurs when you start the engine and those parts grind (metal on metal) against each other for the couple seconds it takes for oil to once again coat them from the oil pump.

The few cents you spend idling your car are an investment in the integrity of your engine itself.

 

[senco78]

more efficient to leave a diesel running