I drive a 2002 Acura TL with almost 80,000 miles on it. I’ll probably keep it at least 3 more years. Lately, I’ve been shutting off the engine when I have to stop at a light that I know will last more than 30 seconds or so, sometimes even as I’m coasting up to the light. This averages 1 extra start per typical 10-20 minute trip. Is the doubled wear on my starter likely to cost me more than I’m going to save on gas?
Yea, it is likely you will not come out ahead on the total cost. You also may find that the cars behind you do not appreciate that delay, even small delay while you start the car after the light changes.
Financially the difference is too small to really worry about either way.
The batteries, starters and the charging system on a hybrid is far different than you have, so while they may save some cost overall, you are not likely to see any savings.
The ignition system degrades a little every time you start your car. Any money you save, which is likely none, would be spent replacing the ignition early. So it will probably cost more than just running the engine.
Since the object of the game is to get where you are going; why take any chances? Although fuel economy is another goal, I think the first goal is at least twice as important. You will always have that one day that you try to start the engine when it is already running. Usually you won’t damage anything but a thousand dollar repair could result. A thousand bucks gets you through the need for gasoline better than a full tank gets you through an empty wallet.
Yes, leave it running.
NO, you are unlikely to wear out the starter in the next three years regardless of what you do. But the next owner will get the bill for your savings.
If you’re in a position where you may need to move your vehicle, which you absolutely are when you are in an active lane waiting at a stop light, then you should not shut off your engine.