I was driving this morning on my commute and I got stuck in traffic due to construction where only one lane in either direction on a local road was open at any given time. Knowing I was going to idle for several minutes, I turned the MINI off to conserve gas. It then dawned on me, "what if I turn off the engine whenever I idle for a light? How much gas would I save?"

When I got home this evening, I googled the idea and got the following two stories:

http://www.celsias.com/blog/2007/03/...0-second-rule/

http://homemadehybrid.blogspot.com/

Has anyone tried this out? It seems like this is a bad idea for the starter, but with the amount I start and stop my car anyway for short trips, this really can't be all too different.

I don't know how true these sources are (I did all of 15 minutes of research on the internets), but I'm curious enough to try it out for one full tank of gas and see how I fare whenever I know on my commute I'm at a red light that will take at least 20 seconds or more.

My commute is 7 miles one way, local driving with at least 8 lights with varying speeds of 25mph to 50mph (one short stretch of 50mph road). I average about 24 mpg during 95% city driving, some days with a lead foot, some days with a light foot. I'll try it out and post back after the tank is done how my mileage changed after turning off the engine at lights.

Does anyone else have any experience in doing this?

 

I do that when I run my range indicator is below 10 miles. I can go a few days like that.

 

Shut off my engine while on the road??? While driving my MINI??? Don't think it's ever going to happen.

 

doesn't starting the engine burn a little burst of gas?.....so if stopped for a very short time, i wouldn't think it was cost effective, but if for a long red light, maybe?

 

It is one of the laws here in Germany to kill your engine when waiting at train tracks and such. I believe they use the one minuet rule here. Anway, it is not to save gas, but rather save peoples lungs.

 

More strain is on the engine, motor mounts and electronics at start up than at any other time. Not to mention that repeatedly cycling the engine on and off increases its temperature, causes wide fluctuations in its temperature and diminishes the cooling system's ability to cool the engine. The couple of cents you may "save" a week doing this will amount to nothing compared to wear and tear and the shortened life of your car and/or its compenents.

 

And if you're in the air conditioning belt, YOU'LL overheat.

 

Hopefully I don't use my AC, and I just have the top down

 

That used to be true, but with today's electronically controlled engines restarts take virtually no fuel. As for wear and tear, I doubt restarts are that harsh, but I have no evidence.

Note a posting on hear earlier about the '08 model that automatically shuts down when stopped (in neutral). Step on the clutch and it instantly starts up again. May be a European thing only, but it's an intriguing idea.

 

Yeah, when I was in Germany there was signs when using the drive-thru to turn engine off.

 

Yep... I once got a 50 mark (just dated myself) ticket for not killing the engine at the train tracks.

 

So 1 tankful of my regular commute on the above described method. I normally get about 24 mpg, and turning the engine off at a light got me to 25/26mpg. Either my technique sucks at doing this, or it doesn't really save me all that much! Needless to say, I'm not going to be continuing this practice! I get more savings if I lighten up my heavy foot on the gas pedal.

 

Question though...why is this being done in the 08 MINI?