went to red? (sslr)
Switch off the engine!
Even with a restart of the engine, you use less fuel overall, than idling oll the time. The gain should be even higher with automatic transmission.
Accelerate slowly, and shift soon!
Slow acceleration means less wear and tear on parts, you have more room for safety, and you can adjust speed easier, by using brakes less often.
How soon you can shift depends on your car and engine. Some allow you to switch gear at 1000 rpm without stuttering, others allow you to switch at 1200 rpm. This needs familiarity with the car. This needs manual transmission, obviously.
Regarding driving downhill: If you have manual transmission, keep the gear enganged, and use it as additional brake. Better to be on the safe side.
In general, an idle motor needs more fuel than one in gear, but the gear needs a certain minimum of rpms, or you'll choke your engine. Which should be avoided, especially with today's engines (you don't want to shorten the lifespan of your engine).
You can determine peak efficiency by reading your car's manual. This value differs by engine power, engine type (gas or diesel), and transmission. |
