There was an article on the auto section of the newspaper that said it is a good idea to turn off your engine when you're at a stop for more than a minute. This was a response from the two "car expert" writers to a guy that asked if his father in law is crazy for turning off the engine at long redlights. Will turning off your car at redlights like that be worse for the car than leaving it on? Fuel savings aside how will it affect the engine in the long run?

 

with this kind of question, you cant really set that aside, lol. it would waste SOOO much gas!

 

the starter and flywheel would get a lot more work. you could waste a LOT of gas before you'd saved enough to replace those...

 

Fine keep consider the fuel savings and weigh it against any of the problems that this will cause. Is it worth it for the 10% or so better mpg?

 

the only way that this is going to make that big of a difference is if the car is off for at least a minute each time (economy wise). And let's just say for example that you drive 12,000 miles a year (average) and get 30 mpg or 33 with turning the car off. so 400 gallons a year at 30mpg or 363.64 gallons a year at 33 mpg. so a difference of 36.36 gallons. At $3.00/gallon that's $109.08 savings per year. If you do that for 3 years and follow all of these instances to the letter you will save $436.32 over a 4 year period. However, I'd be willing to bet that you'll ruin at least a starter and a battery if not a flywheel. The cost of those repairs would far exceed the fuel savings you gain.

So if you compare fuel economy savings to wear and tear costs on the vehicle this little fuel saving tip would ultimately cost you money in the long run, not save you anything. And that's calculated at a 10% increase in economy (which sound high to me)

 

wow, nice calculations
i got lost somewhere in those numbers....

 

I love calculations... Problem is, this one is all hinged on one big assumption.
Problem I have is what is the basis for assuming the mileage will go up by that amount? I bet the improvement will be less that that.

 

yeah, i dont think it would be that much...

 

thats all an assumed thing, when you think about it constant stop and go traffic will waste more gas and most of the time you wont be sitting there for a minute, im not saying that red lights dont sit there for more then a minute, but has anyone looked at how much fuel you use turning on the car? or how much is used at idle for every car? has anyone wondered if this was defined for carb engines or fi? many factors to look at yet cars are not the same model to model........ but i vote for doing things that will shorten the life of your starter ^_^ especially when you can sit lights more then 10 times a day that last more then a minute

 

When supposed "car experts" recommend that people do this I am dumbfounded. Cranking your car probably uses as much fuel as 1-5 minutes of idling. Plus repeatedly cranking and shutting the car off is not good for the starter & flywheel as nasty already said.I highly doubt the gas savings would be as good as he said, but I know he was trying to make a point with a "best case scenario." If you like your car, don't do this.
I have a feeling those "experts" that suggest it probably own stock in car repair facilities