Is the car using more fuel at 4,000 RPM(for example) in 4th gear then 4,000 RPM in 3rd gear... or is it the same?
mr.grassie said:If for example, you are accelerating hard along a strip of road in third gear, your fuel consumption may be (for example) 22mpg, but when you change into 4th the load on the engine increases, because you loose the mechanical advantage provided by the lower gear. therefore the engine must work harder. for the engine to work harder, it must use more fuel, and the economy would then drop to say, 17mpg.