How Many Gears Are There?
2 Answers
Nowadays, the number of gears in a transmission is generally between 4 and 8. In the gears of a transmission, the lower-numbered gears are called low gears, while the higher-numbered gears are called high gears. Introduction to the Number of Gears: The number of gears usually refers to the quantity of forward gears in a geared stepped transmission. The more gears there are, the better the vehicle adapts to different driving conditions, which can help reduce fuel consumption. Principle of Gears: The power output from the engine crankshaft is transmitted through the clutch and directly input to the transmission's input end. At this point, the engine speed is high, but the torque is small, making it unable to directly drive the wheels. It must go through a series of steps to reduce speed while increasing torque to propel the wheels forward. The number of gears also significantly affects power performance. For example, if there are more gears, the first gear can have a larger gear ratio, allowing it to output higher torque when starting in first gear.
Having driven cars for so many years, the changes in gear numbers have been quite significant. I remember most manual transmissions in the 1980s had only 4 gears, whereas today's mainstream manual transmissions typically have 5-6 forward gears. Automatic transmissions have seen an even greater leap, evolving from old-style 3-speed units to many new cars today featuring 8-speed, 9-speed, or even 10-speed transmissions. For instance, my 8-speed automatic maintains a steady RPM of around 1500 on the highway, offering about 15% better fuel efficiency compared to a 5-speed, and the ride is as smooth as floating on a cloud. More gears mean finer gear combinations in the transmission, resulting in smoother acceleration without jerks, making it ideal for long-distance highway driving. However, the increased precision of internal components also means more frequent maintenance to avoid abnormal shift timing. In summary, modern cars usually have 5-6 gears for manual transmissions and 4-10 gears for automatics, depending on the brand and budget. The goal of multi-gear designs is to enhance efficiency and comfort, profoundly impacting everyday driving.
