10-Second Rule to Save Fuel

When I came across this site, I found myself incredibly surprised. We all know that an idling car gets 0 MPG, but how much time is alright?

10 seconds, it turns out. After that, an idling car wastes more fuel than a full startup would consume. In today's modern fuel-injected engines, starting a warm engine is nothing.

Perhaps you're concerned that continually shutting off and restarting the vehicle is hard on the engine. But studies show that frequent restarting has little impact on engine parts such as the battery and starter motor. The wear on components that restarting the engine causes adds about $10 a year to the cost of driving – money that you'll likely recover several times over in fuel savings from reduced idling.

On winter days, you only need 30 seconds at most of warm-up time. Researchers have found that driving is the best way to warm a cold engine. That is because idling only heats the engine, not the steering, suspension, and transmission.

Excessive idling could also lead to engine damage. Idling doesn't fully burn the fuel, and the leftover residue mixes with oil and sticks to engine parts. Not good.

My source

Nice find, I always assumed I'd be better off running the car idle for 10 or 15 minutes than shutting it off. It does drain the battery, though, so starting and shutting it off time and again may save fuel, but if you're not going far, it'll kill your battery.

Yeah, I'm not suggesting we all shut off our cars at traffic lights, but if you're waiting for Johnny after soccer practice, it really makes sense.

Car batteries are really durable though. During full work days in the summer, my construction crew would blast music from our pickup truck, with Sirius radio also draining it. The battery light never went on once. And I think it recharges fairly quickly.

At any rate, I'm really going to have to start putting this idea into practice. As a high school senior, I'm always looking to save money.

Of course it's not a good idea to peel out of your driveway and hit the highway at 150kph within a minute.
When after 10 seconds or less in summer, or 10-30 seconds in winter the engine is still a bit tight. So let it warm up and loosen up (heat expanded metal)) a bit before you take it to the track.
Be easy on the gas pedal.

DailyFuelEconomyTip Corroboration

I have put this idea into practice over the last month and have averaged 10-15 extra miles on a tank. It's not much, but it saved me some cash, and I'm happy.

Any other success stories out there?

80% of engine wear happens in the first 10 seconds of startup (which is what I expected this thread to be about).

The more you start your car, the more wear you're putting on it, if it has cooled enough for oil to drain back down to the pan, and coolant to begin contracting again. Even warm, you're wearing on the starter.

On the other hand, if you MUST eat fast food, take a look at the line of cars, and consider getting off your seat and walking inside. Odds are, you'll be served faster "in person," anyway.

And you'll get to fill your own drink with 90% soda instead of 90% ice!

From a cold start you want to let it idle long enough for the oil pressure to come up to normal. People who start and take off immediately are destroying their piston rings.

Frequent starts without more than 10 or 15minutes of travel will destroy your battery unless you run a deep cycle or hybrid. It will also destroy your exhaust as condensation buildup inside the steel pipes will not be evaporated and will eventually rust out.

It's all very well, but when you swicth it off the heating and/or the aircon goes off too.

Can't I just plant a tree when I get home or something?

It's all very well, but when you swicth it off the heating and/or the aircon goes off too.

Can't I just plant a tree when I get home or something?

That's a perfect example of why I think we as humans won't voluntarily change our habits. We have become so accustomed to creature comforts, and the idea of using what we have until it's gone, that we simply won't change our habits voluntarily. This, in my oppinion, will be the biggest problem of all.

I drive 50 miles to work and back each way and spend about $120 per month on gas. At what point is it worth it to move closer to my office?

When you live more than 10 miles from work.

Really it depends entirely on your personal and financial situation. Crunch the numbers, taking into consideration of things like cost of living closer to work, and if the impact of distance is severe... there yah go.