I’ve read that you should shut your engine off when sitting?

Starters are pretty durable, but they won’t last forever.

Shutting down the engine is a good idea to save fuel if it is for a significant amount of time. 10 sec seems way too short.

Newer cars are coming out where they shut off the engine while the vehicle is stopped and then start them when the gas pedal is applied. To do it yourself for 10 sec seems like a waste.

its always best to shut down at long lights to save gas but at a quick light no u waist more gas trying to start back up than just leaving it running

unless you have a car set up for this it will wreck your starter, the ring gear on the engine flywheel the battery and the alternator, also because standard cars use richer mixtures to start you may use more gas doing it than just leaving the engine idling, VW tried it a few years ago and all of the cars needed expensive repairs because of the thousands of starts

You’ve just run into a catch 22 – Because the on-&-off cycles are hard on the engine, because the oil drains back into the crankcase every time you shut it off, & the engine starts ‘dry’. I’m sure there’s a balance point somewhere between burning gas & off-on cycles of the engine, but your guess where it is is as good as mine…

the whole 10 second thing depends on what you are running and how much gas it takes to start it …v twin will not be too bad but a 4 cylinder will be worse and a 6 or 8 might as well let it run because it does take a lot of gas to get them running…also hard on the engine to stay at operating temp that way and reall is bad on starter flywheel battery and alternator ….also fuel pump because none of those things excluding fuel pumps are made to run continuously and the more you turn your fuel pump on and off the worse….you hardly ever hear of a fuel pump going out in the middle of the interstate usually it goes out when you shut it off and the next time you try to start it…well it wont start….my advice you know its running now so why shut it off in the middle of a road….plus its a motorcycle so your not really using that much gas anyway especially if its at a light b/c you are using the clutch so there is no load on the engine unlike a car that has an automatic tranny where unless you put it in park or nuetral there is a gas robbing load put on your engine…

i used to shut off my cars engine for just about that, any waits longer than say 10-20 secs. other than the wear and tear on the starter there are other objections though minor depending. one is the fact that every time you shut off the ign on spark ign engines, the alternator tends to surge. this is ok and its made to take it but voltage spikes shouldn’t be encouraged more than needed. also if the cars oiling system is poor constant starting is harder on it. also the EGO sensor(O2 sensor) will go cold often if its not heated internally. gas engines tend to take to that very well though all in all. i was able to get maybe 40 MPG ish vs just above 30 in my mazda but that was doing lots of other things as well. for typical driving i find anymore its just not worth the trouble unless your going to sit for a good while(like a RR crossing). also i now avoid it since its unwise to do with turbocharged engines. don’t ever do that kind of thing with diesel engines.

edit: it actually takes very little fuel to hot start a gas engine carb or FI. the injector pulse width is quite short usually when the ECU senses that the engine is warm. and a carberated one will dump fuel at a rate similar to low idle speed when hot starting with the butterfly only cracked.

Alot of good points made here.

I do not see the point in shutting off your vehicle at stop lights, but avoiding excessive idling time like when picking up friends or running in the convenience store. I have a bad habit of leaving my car running in my friend’s driveway even when it takes them 30 mins to get ready to leave once I’m there (yes, it’s a female).

Not only do many vehicles use a rich fuel mixture when starting, but after starting, it will full-field the Alternator to replace the charge taken off the battery. This will add a bit of a load to the engine and it will alter timing and increase injector pulse to compensate for the engine having to work harder. There is more fuel used in the first 30 seconds of idling then if you just left it idling.

There are more effective ways of decreasing your fuel consumption.

Let’s go back the the stop lights. Start slowing down sooner, don’t drive all the way up to it and brake harder to stop, gradually slow down. You don’t have to be the one leading the pack away from the light, accelerate easily and at a nice constant speed.

Don’t always drive so fast. It’s true that this has changed some over the past 30 years. newer vehicles are capable of running higher speed with less fuel consumption then older vehicles, but doing 80 in a 55 is still wasting fuel.

Take out extra weight. Don’t sacrifice the spare tire and jack, keep those in. But the trunk full of junk, the baseball bat and bowling balls… they don’t always have to be with you.

TIRE PRESSURE!!! I cannot say it enough. Check your tire pressure. Keeping your tires properly inflated and altering your driving habits are the 2 best ways to reduce fuel consumption.