In a conventional petrol car, which driving pattern tends to increase fuel use per kilometre compared with smooth travel at moderate speed?

Correct answer

Urban traffic with frequent stops and acceleration.

Urban stop-and-go driving with frequent starts and acceleration tends to increase fuel use per kilometre. Repeated acceleration and unnecessary use of low gears increase consumption; idling during stops also uses fuel without covering distance. Idling is not the mechanical cause of using low gears. This comparison does not mean every urban road uses more fuel than every interurban road: vehicle, speed, traffic, gradients and driving style all matter.