If you can’t afford (or aren’t in the market for) a hybrid, flex-fuel, or diesel vehicle, there are still practical steps which you can take to reduce your fuel consumption. That doesn’t mean to go as far as some people (hypermilers) who always keep their windows closed, don’t use the A/C, and perform dangerous driving maneuvers in order to maximize fuel economy.
One of the most preventable fuel wasting activities is that of idling the engine. Idling is sometimes an act of choice, e.g., “warming up” your car during the winter for a few minutes or waiting to pick up someone while leaving the engine running. More often than not, idling is forced upon us by traffic jams and lengthy red lights.
Idling is detrimental in a number of respects:
- It is a waste of fuel.
- It contributes to engine wear and corrosion.
- It harms the environment.
A Canadian government study has offered a simple solution: if you know that you will be idling your engine for 10 seconds or longer, simply turn off the engine and restart when you are ready to go. As stated in the study, “Idling your vehicle for more than 10 seconds uses more fuel than it would take to restart your engine.” Apparently, the prevailing school of thought which supports idling over restarting is based on (like too many others things) an anachronism: the assumption is that modern, electronically supported combustion engines are to be run as their “dumb” predecessors. It is acknowledged that restarting your engine instead of idling may contribute to quicker wear of the engine starter. The cost of repairing/replacing the starter, though, is insignificant compared to the savings in gas. Anecdotal evidence shows a 10% savings in fuel per-tank.
The 10 second rule is apparently the law in Basel, Switzerland, and they have seen a tremendous reduction in pollution as a result.
(Source)