Written by Yes it normally does, but if you let the revs drop so low, that your engine starts chugging, or struggling in any gear, then that will hurt fuel economy. If it’s chugging, then you need to drop a gear, ie chugging in 3rd, you drop to 2nd. What you must understand is that, the engine is just a power source, with a fixed rev range, the gearbox is a means to tap that power, so in theory, the lowest revs, in the highest gear, would yield the best economy. In practice though, if you are driving along a flat road in your highest gear, (5th or 6th) depending on how many gears you have to play with, your car will struggle below 35mph in it’s highest gear, to get the best economy, you need to keep the revs as low as possible, in the highest gear, without stressing the engine, in most cars, this is normally achieved on a flat road, in 5th gear (highest) at around 30-40 mph, depending on the car in question, it is always much easier to apply this driving style in a Diesel car.
For more Fuel Economy Tips, please read the other posts.
