One of the most effective means to master fuel consumption is to follow a simple rule: no more than 2,500 rounds/minute
Does your vehicle have 5 or 6 gears? Good. This is the case for almost 95% of vehicles sold or driven in Europe in 2014. Check how many revolutions per minute the engine is running, when you are in the highest gear. At highway speeds, make sure you do not exceed 2,500 revolutions per minute. You will keep your engine and consumption and reach a correct speed without exceeding the limit.