Besides the obvious (fuel consumption, environmental pollution) what are the negatives when it comes to idling? There was a post some time back debating which was worse on the engine: idling or restarting. I've really like of some of the experts to weigh in here.

I drive in NYC a lot and ildling is inevitable. Does it really harm the engine? If so, why? It would just seem to me that it would be less harmful than coasting at like 5mph.

 

I'm almost positive restarting consumes more fuel, not the other way around. For years i've always been told restarting was worse, and idling was fine, also it was my father who told me this and hes been a mechanic for almost 30 years. Dont bash me if i'm wrong, i'm just tellin you what i think i was told

 

Per Newtonian physics, more force is required to change the state of an object than is required to allow it to remain "at state".

Think of it like this; when do light bulbs most frequently blow out? A) When you turn them on, or B) after they've been on and are at operating temperature? A, right?

I can tell you from experience that most data servers have far more running hours on them before they experience hardware failures than do the typical workstation that is turned off at night. The reason? State change.

Starting and stopping a car over and over again is far worse for the car than allowing it to idle. Todays engines cool themselves just fine with no airflow or load on them, but when you stop and start the engine repetitively, you cause metal, plastic, and rubber to constantly expand and contract over and over.

 

yeah, what he said lol

 

Starting the engine is more harmful than letting it idle. For a second or two, the oil is completely at the bottom of the pan. Starting the car has the pistons going metal against metal which can tear a little bit of the metal off. It takes a long time for this to affect an engine however.

 

Hey guys I agree 100% that starting the engine is more harmful.

My question is about idling. I've heard so many people comment on how bad it is for your car but have never gotten a good explanation as to why.

This is the post that got me wondering about it: https://my350z.com/forum/showthread....ghlight=idling

 

you could also say that it depends on the situation. Drive through leave it running, but if your waiting in the car while your wife or similar runs into the store for more than 30 min might be better to turn it off. You could say its case by case.

 

I can't imagine what about idling is bad for the engine. While it's running it's being cooled, lubricated, and is under really no load. Yeah, sure you're consuming run-time hours, but probably at such a low rate that it's of no consequence.

IRT city driving, the only detriment is to your clutch because it's the one making all of the "state changes".

 

That's exactly what I thought. Thanks for your well though out reponse.

As far as my clutch goes, I had an 03Z with 17000 miles on it and the clutch was still strong when I got rid of it. And this was my first stick, so it did ride the clutch a lot. Now that I'm a semi-pro at driving stick, I'm not riding the clutch so much while in traffic, but I am launching it hard while racing. Hopefully it'll last as long as the other one.

 

cooling is not as good while idling....there's no wind going through the radiators...

 

^^^^Thats what those nice electric fans are for. To pull air through the radiator.

 

Hybrids turn the gas motor off nowadays to save fuel. Think about it.

 

However for a hybrid to restart the engine I believe it is an entirely different concept then with normal cars. I think it is the actual turning over of the engine and gettin it going that consumes more gas and hybrids use a different technique. Anyone own and Insigh or Prius that wants to fill me in??

 

So in conclusion, idling is not really bad for my Z. Just bad for the environment and my gas mileage. Right?

 

correct

 

yes, the light bulb and PC analogies dont hold true. the reason a bulb burns out is due to resistance as it relates to temperature. a cold filiment allows like 10x as much current to flow through for that first nanosecond then it will when it warms up. superconductors are super cold, if they were hot they wouldnt be super conductors, same idea for a light bulb, but they design them with them running hot in mind. the cold start is a nescessary evil and is what hurts them. if you allowed a bulb to run non stop 24/7, Id be suprised if it ever blew out.

PCs have the same thing, they are designed with 1 temp, and when they first start, they arent at that temp. making the resistance less and thus more current.

cars are not electronic, ignoring the damage to the starter, or the ecu or whatever that I dont know anything about, the engine itself could care less. there is an arguement you could make about a cold engine, but the engine does not cool down particularly quick; so if you stop it and restart it I dont think your pistons and cylinders would have cooled down sufficiently to make the clearances any different.

 

duh i am stupider now.