What are the differences between first, second, third, and fourth gears in a car?
4 Answers
Here are the differences between first, second, third, and fourth gears in a car: 1. Different speed ranges: First gear is used for starting, with speeds under 20 km/h; second gear is used between 20-40 km/h; third gear can be used between 40-60 km/h. 2. Different functions: When starting in first gear, it's best to accelerate slowly. First gear is generally used only when starting or turning. Third gear at 2500-3500 RPM provides suitable engine torque for overtaking or climbing steep hills, but fuel consumption and noise increase. Second gear at 2000-2500 RPM is more fuel-efficient (varies slightly depending on the engine), with moderate torque and relatively low noise, making it suitable for normal driving. 3. Different driving conditions: First gear is the starting gear, used when the car begins moving. Its gear ratio is similar to reverse gear, so it's not suitable for sustained high-speed operation. Generally, you can shift to second gear once the car gains momentum. Second gear is the passing gear, mainly used for navigating complex road surfaces or handling difficult situations. Third gear is the transition gear, primarily used for low-speed urban driving - it allows easy transition to fourth gear when accelerating or downshifting to second gear when decelerating.
Over the years of driving manual transmission, I've figured out some tricks. First gear is like an ox pulling a cart—tons of power but slow, essential for steep hill starts, though it roars when revs exceed 2000 rpm. Second gear is like a warm-up jog, slightly jerky when shifting up, but perfect for city driving between 20-40 km/h. Third gear is the real all-rounder, cruising smoothly and fuel-efficiently at 40-60 km/h; drop back to third for overtaking, and the acceleration feels sharper than in fourth. Fourth gear is the most effortless, with the engine purring above 60 km/h, maintaining just 2000 rpm on highways, saving half a liter of fuel compared to third gear.
When fixing cars, I always tell apprentices: imagine the transmission as a set of magnifying glasses. First gear amplifies the engine's power over fourfold, making it effortless to start a two-ton car. Second gear drops the RPM but doesn't feel sluggish—the gear ratio makes the wheels spin 30% faster than first gear. Third gear starts focusing on balance: for every three engine rotations, the wheels turn once, avoiding the noise of lower gears while retaining passing power. By fourth gear, it shifts directly into fuel-saving mode—especially for naturally aspirated engines, cruising at 80 km/h at 2,500 RPM feels particularly smooth. For turbocharged cars, this gear still holds potential energy, waiting to unleash its power.
For beginners driving a manual transmission, remember these three tips: Use first gear for crawling like a snail (under 15 mph), second gear for navigating alleys (under 30 mph), and third gear for cruising on main streets (50 mph is sufficient). Only shift to fourth gear on expressways for better fuel efficiency. Yesterday while coaching a student, I noticed they were revving the engine harshly at 40 mph in second gear—shifting to third would've been much smoother. In old city areas with frequent traffic lights, I mostly toggle between first and second gears, but immediately shift to fourth on elevated roads to keep the RPM needle comfortably below 2000.
