What are the consequences of high speed in low gear?
2 Answers
Low gear at high speed will lead to increased fuel consumption, loud engine noise, and engine wear. Here are the relevant explanations: 1. Principle: When driving normally, continuing to use low gear with high throttle causes the engine to operate at high speed while the vehicle's mileage does not increase. This results in higher fuel consumption per 100 kilometers. Additionally, the thermal energy (power) generated by the high-speed engine operation cannot be effectively converted into thrust to propel the car forward. This excess thermal energy is then released by the coolant through the radiator, causing the engine water temperature to rise excessively. Prolonged operation under such conditions can damage the engine and increase wear on its components. 2. Extended information: Every vehicle has an economical speed range where fuel consumption is minimized. Driving below or above this speed range increases fuel consumption, and below a certain speed, fuel consumption rises significantly.
I've been driving for fifteen years and have encountered several instances of forgetting to shift up to higher gears at high speeds. Once on the highway, my speed was nearly 120 km/h, but the gear was stuck in third. The engine RPM soared above 5000, the roar was so loud that conversations in the car became inaudible, and the car shook like an earthquake, making the steering feel unstable. Fuel consumption jumped from an average of 8 liters to 12 liters per 100 km, costing me dozens of yuan more for every hundred kilometers driven. What worried me more was the engine overheating—the temperature gauge showed a red warning. After stopping to check, I found the engine oil was nearly burnt dry. The mechanic said this would accelerate piston ring wear and halve the lifespan of the crankshaft and bearings. Now, whenever I hit the highway, I make it a habit to check the tachometer, keeping the RPM between 2000 and 3000, which is optimal. Saving money, peace of mind, and safety come first. High speed in low gear is a bad habit, and doing it long-term can lead to premature engine failure. I advise both new and experienced drivers to pay attention to the right shifting timing.
