Turning the engine off and on in stop and go traffic saves gas but what does it do for the life of battery and starter?
It likely saves a lot less fuel than you think. Starting may well use more fuel than just idleing. It is also hard on the starter.
Now if you are talking about idleing for a hour or two, well yea turn it off.
The exact amount is not easy to compute as there are a number of factors, but it is wise to not play
If the engine is going to idle for more than 60 seconds, turning the engine off will save you gas. This is true whether you are at a drive-thru or at a red light. However, that doesn’t necessarily make it a good idea.
Before the modern age, when cars didn’t have electronic fuel injection, the engine used more fuel to start than it does now. Also. the myth about using a lot of fuel to start the engine only applied when the engine was cold. This is similar to the myth that turning on a fluorescent bulb uses more energy than leaving it on. Both myths are bogus.
Hybrids and other cars that are designed shut down automatically when not in use have special starters that are built to stand up to heavier use than the average starter in the average car. If your car doesn’t shut down on its own, shutting it down at every red light will wear out your starter faster.
In stop-and-go traffic, just let the engine run. If your car isn’t smart enough to shut itself down, your shutting it down and restarting it manually will wear out your starter.
It doesn’t save enough gas to pay for the premature failure of your starter. And, if most of your driving is stop & go, your battery is sure to stop…& not go. You’ll quickly drain it dry. Whitey actually explained it well.
@whitey, wifes Audi has stop/start. It won’t kick in till the car is warm to help battery and engine wear. Handy in a diesel that sounds like a dumper truck at idle, but can be annoying and has an over-ride button on the dash… 
Isn’t the new Focus or fiesta getting stop/start too?
@rona1941 buy a new car with the stop/start tech already on it. though I do believe that the battery and starter are listed as maintenance items in the maintenance schedule.
If they can design a golf cart which for decades, has has been doing this successfully, many times more than any automobile, I wouldn’t worry about it. Besides, as bscar2 implies, it’s just another maintenance item that auto companies can under engineer to “profitize” on. Besides, if you buy a car from a manufacturer with a good repair history, you will have no more problems then a car without this feature.
The Prius has been doing it for years with little ill affect in reliability.
Dag, every golf cart I’ve used has been electric. And they only need to drag you around for 36 holes. At very low speeds,
Prius, as well as other cars that use the on/off engine technology, have starter systems designed for repeated starts. Most cars don;t.
I doubt that so many cars in Europe would have this feature if it didn’t conserve fuel. It doesn’t have to save much to have a large effect when there are millions of cars that use it. I had a BMW 118d as a rental that used it, and it was difficult to get used to. But it worked like a charm.
It does conserve fuel, but as already mentioned unless the starter, battery, and charging system are appropriately designed it’ll prematurely kill one or more of them.
Let’s do a ferinstance. Let’s guess that the average starter is designed to withstand 5 starts a day (5 drives), for 10 years. That’s 27,375 starts. If you stop and restart at every stoplight in my driving environment you’d probably be starting the engine 25 times a day (5 times per drive) instead of 5 times (once per drive). That means you’d reach the starter’s design life in 2 years instead of 10. You won’t save enough gas to cover that cost.
In addition to the very valid wear & tear factor that has been mentioned, the OP should also consider the potential safety factor. If you are stopped at a traffic light and see an 18-wheeler or other vehicle hurtling toward you from the rear…do you really want to lose the 5 seconds or so that it would take you to restart the engine and put the transmission back into gear in order to move out of the way of that vehicle?
Five seconds might not seem like a lot of time, but in a scenario like the above, it could mean the difference between life and death.
In the case of newer cars with an automatic stop/start system, simply lifting your foot from the brake will restart the engine, so there would not be as much of a lag before you could get yourself out of harm’s way.
The starters in most modern cars are pretty robust. Batteries are subject to a lot of drain due to modern electronics which stay on when you turn off the motor. Still this is usually in traffic and the battery will recharge when you get going again.
For me the issue is will it save gas? And, is it worth the bother? I use a 90 second rule. Meaning if the traffic isn’t likely to move again for 90+ seconds I turn off the motor. For me this is a rare event and ususally relates to construction tie ups or waiting out an accident to be cleared.
In fact you’d likely save gas almost immediately if you killed the motor at any traffic light. In NC where it seems traffic lights take forever to change you’d definately save gas. But, is it worth the bother? Hybirds are designed for this gas saving tactic and they kill the gas motor almost immediately.
If you killed and restarted the motor at virtually all traffic lights you’d save some gas. But, a typical short trip might now entail 10 start/stop cycles instead of 2. Over time (like a few years) that kind of use would likely burn out a normal starter.
Same…http://www.golflink.com/about_4744_electric-vs-gas-golf-carts.html
44 percent of courses use gas powered golf carts. Just because you have never used them does not mean they are not used successfully in many places and acording to the this article, the operating costs are similar.
Your comment that the Prius is designed to stop and start is correct. What you fail to add is that any car that automatically starts and stops will also be designed to do it. What’s the problem. Cars have systems that do it successfully and any car that has problems won’t sell. My point is it ain’t brain surgery and the technology has been around a long time and used with few problems.
What I did not infer mistakenly is that according to, OP the driver is doing it. In that case I was completely wrong. I interpreted it to mean that the car did it automatically. My bad. It never occured to me that anyone would be naive enough to turn the car off at every stop. Why don’t we just turn the TV off at every commercial, hang up whenever we are put on hold etc.