Engine run or off: Does frequent restarting actually burn more fuel than idling?

It is a general belief that restarting the engine frequently during stops at traffic signals burn more fuel than idling at the stops, making the riders and drivers idle their vehicles at stops on streets adding to environmental woes.

“Idling” refers to running a vehicle’s engine when it’s not moving, such as when the commuters are at a red light or stuck in traffic. Idling is part of the process of driving a car and is a common occurrence for most drivers. However, idling may not be the best for the car, fuel consumption, or the environment.

As per some studies, idling uses up to 2 ltrs of fuel per hour (although it varies depending on the type and size of the engine). It may not seem like much, but idling for a few minutes every day can cost a lot of money per week.

According to ‘Verizon Connect’, letting a vehicle idle does more damage to the engine than starting and stopping. In fact, running an engine at low revs (idling) causes twice the wear on internal parts compared to driving at regular speeds. Excessive idling can also cause a buildup of carbon residue in diesel engines. Because the engine is not operating at its optimal temperature when idling, fuel is only partially combusted, leading to fuel residue buildup on the cylinder walls.

Moreover, it is a myth that cranking the engine every now and then causes more fuel consumption. It might have held some semblance in the engines of bygone era. But modern engines built in the last decade or so use much less fuel when starting up.

Tips to save fuel during idling:

-For drivers of small vehicles, it is recommended to turn off your engine if you plan to idle for longer than 10 seconds.

- Don’t idle to warm up your engine while starting the vehicle for the first time in the day, start driving straight away. The engine will warm up quicker.