Fuel Saving Tips
If you're going to be sitting in your car with the engine running for more than 30 seconds or so, it saves fuel (which would be zero mpg at a standstill) to turn the engine off. Hybrids are famous for this, and it's a bit trickier to do in a regular car, but if you're at a long light, or waiting in a long line of cars, it does decrease fuel usage to simply turn off your car's engine.
posted by mathowie on August 1, 2008
this tip works for 70% of voting Fuelly members.