What is the Rear Axle Ratio?

[VanKayden]

Rear axle ratio is an important parameter of the engine, commonly known as the rear axle ratio, and its academic name is the final drive ratio. The rear axle ratio refers to the gear transmission ratio of the main reducer in the vehicle's drive axle. It is equal to the ratio of the rotational angular velocity of the driveshaft to that of the axle's half-shaft, and also equals the ratio of their rotational speeds. Additional information: 1. Speed ratio: The speed ratio of the vehicle's drive axle, also known as the speed ratio of the main reducer assembly, can be understood as the amplification of the torque transmitted from the driveshaft, indicating how much force is needed to propel the vehicle. 2. Higher ratio, higher torque: The larger the ratio, the greater the output torque, and the slower the output speed. To achieve greater power (torque) output for the vehicle, suitable for climbing or heavy loads, a relatively larger final drive ratio (e.g., 6.83) can be selected to meet the requirements, though this sacrifices speed. 3. Lower ratio, lower torque: The smaller the speed and torque ratio, the smaller the output torque, and the faster the output speed. By selecting a relatively smaller final drive ratio (e.g., 3.89), the need for higher speed can be achieved.

[JulianDella]

I usually enjoy studying mechanical structures while driving. The rear axle ratio refers to the rotation ratio of the large and small gears on the rear axle. For example, a higher ratio can provide strong traction, which is especially suitable for hauling goods or climbing hills when the engine's explosive power is sufficient. However, fuel consumption tends to be higher at high speeds, so I have to frequently check the vehicle's condition. I remind beginners not to overlook this parameter, as it directly affects power response and fuel efficiency. When choosing a car, it's crucial to consult with a mechanic to match the appropriate ratio.

[McLaura]

I'm a new driver who just got my license. During driving lessons, my instructor briefly mentioned the rear axle ratio, which is essentially the relationship between engine rotation and wheel speed. Choosing a higher ratio means the wheels turn slower, making it easier to climb hills, but it consumes more fuel on long trips. For regular city commuting, a lower ratio is more fuel-efficient. I recommend trying different scenarios to feel the difference. Remember to check the specific values in the maintenance manual.

[VanGeorge]

When modifying my car, I pay special attention to the rear axle ratio, which determines the acceleration from a standstill—higher ratios provide stronger explosive power for drag racing or track use. For daily driving, avoid overly aggressive ratios as they may cause excessive wear on the drivetrain. Online forums are great for sharing experiences to help select the right gear configuration.

[Erica]

Having driven for over a decade, I prioritize cost-effectiveness. A higher rear axle ratio means the engine turns more times for each wheel rotation, offering better short-distance acceleration but consuming more fuel. Opting for a lower ratio saves fuel during high-speed cruising, especially cost-effective for long trips. Regular maintenance checks on gear oil can extend the service life.