Should You Shift Gears Based on RPM or Speed?
3 Answers
Shift gears based on RPM. Here are the relevant explanations: 1. Torque: The reason a car needs to shift gears is due to new demands on the torque provided by the engine, and the torque the engine can provide is directly related to RPM. 2. Things to note: For a specific car model, the engine RPM corresponds to a particular speed in different gears. If you know this specific relationship, you can also shift gears based on speed. For example, if you need to shift gears at 2000 RPM, and the corresponding speeds for 2000 RPM in 2nd, 3rd, and 4th gears are 15 km/h, 25 km/h, and 40 km/h respectively, then you can shift gears at the corresponding speeds.
When shifting gears, I mainly watch the RPM, which is related to my daily commuting habits. Normally, I upshift around 2000 RPM to save fuel and prolong engine life, as lower RPM means less engine load and reduced fuel consumption—saving a bit on gas over dozens of kilometers. I also consider speed; for example, in city traffic, I shift to second gear at around 20 km/h to avoid engine shuddering. Listening to the engine sound is crucial too—if it’s buzzing too loudly, it’s time to shift. Early on, I clumsily focused only on speed, but later realized the tachometer more directly reflects engine stress. On steep roads or when carrying heavy loads, I downshift to maintain higher RPM for power and avoid stalling. Developing this habit has made driving smoother and extended my car’s lifespan.
When shifting gears, I prefer to watch the RPM, especially when driving fast or needing explosive power. For example, when overtaking or climbing a steep hill, I step on the gas to let the RPM surge above 5000 before shifting, which instantly unleashes the power and makes the car much faster. With speed assistance, such as maintaining 100 km/h on the highway in sixth gear, it's more stable, but if the RPM is too high, the engine can easily overheat. Listening to the engine roar is a signal—when it starts to scream, it's time to shift. I think this strategy suits scenarios where driving passion is pursued. The fuel consumption might be higher, but it's exhilarating to drive. Automatic transmission cars don’t have this issue—they adjust on their own. Overall, the engine's condition is the key; don’t just stare at the dashboard.
