Many of our driving habits were established decades ago. With the advancement of engine technology, it is necessary to change one's driving habits appropriately, such as driving at low revs and high gears.
Every revolution of the engine requires fuel consumption. At the same speed of 40km/h, the upper third gear engine needs to rotate 1863 revolutions per minute; 1466 revolutions in fourth gear, a decrease of 397 revolutions (21%); The fifth gear has 1163 revolutions, a decrease of 700 revolutions (38%). If road conditions do not require frequent changes in driving speed, third, fourth, and fifth gears can all meet the requirements of overcoming driving resistance. Using fifth gear driving can obviously reduce engine speed and achieve fuel efficiency.
From another perspective, the output torque of third and fourth gears is much greater than that of fifth gear, which means there is a lot of reserve power available for use. Therefore, when overtaking or accelerating, simply shift back to fourth or third gear. In terms of the coordination between driving speed and gear, it is more necessary to decide based on the specific vehicle model, rather than how the coach teaches or what others say. A former car enthusiast listened to me talk about the driving method of low speed and high gear, and gave it a try. He said that his car uses fifth gear for driving above 40km/h without any problems, which can reduce the number of gear changes and fuel consumption compared to before.
When the engine speed is constant, the fuel injection speed is the same, but if different gears are used, the vehicle speed will be different, and the average fuel consumption per 100 kilometers will be different. At the same time, the fuel consumption of the engine is the same, but at high speeds in high gears and long driving distances, its fuel consumption per 100 kilometers will be lower; When in low gear, the vehicle speed is low and the driving distance is short, resulting in a higher average fuel consumption per 100 kilometers.
The gear should be appropriate, try to be high or low as much as possible. For example, if you are driving at the same speed and not as fast as 80 kilometers per hour, you can either drive in third gear with a large throttle or in fourth gear with a small throttle. Which one do you say is more fuel-efficient?
But it doesn't mean that just being in a high-end position will definitely save fuel. To avoid the phenomenon of dragging gears here. Dragging refers to the phenomenon where the driving force is less than the driving resistance, and if the engine is not downshifted in a timely manner, it will produce an unstable working state, which is called dragging. It is often caused by too high a gear, and when this phenomenon occurs, the damage to the engine and transmission system is significant.
