1. Mechanical Advantage:
- A lower numerical differential gear ratio (e.g., 3.0:1) provides a greater mechanical advantage, allowing the vehicle to accelerate more efficiently from a standstill and provide better low-end torque. However, it limits the vehicle's top speed potential.
- A higher numerical differential gear ratio (e.g., 4.5:1) decreases mechanical advantage, resulting in less torque multiplication. This can limit acceleration from a standstill but allows the vehicle to reach higher top speeds once in motion.
2. Engine Revs and Final Drive:
- Differential gear ratios directly influence the engine's revolutions per minute (RPM) at a given vehicle speed. Lower numerical gear ratios allow the engine to spin at a lower RPM for the same vehicle speed compared to higher numerical ratios.
- At highway speeds, a lower differential gear ratio will keep the engine RPM lower, promoting fuel efficiency and potentially reducing engine noise and wear. However, it limits the top speed potential.
3. Transmission Gear Interaction:
- Differential gear ratios work in conjunction with the vehicle's transmission gears. Lower differential gear ratios require the transmission to shift gears more frequently to achieve higher speeds, while higher differential gear ratios allow the transmission to stay in higher gears for longer, enabling the vehicle to reach higher top speeds.
In summary, lower numerical differential gear ratios favor low-end torque and acceleration but limit top speed, while higher numerical differential gear ratios sacrifice low-end torque for increased top speed potential. Choosing the appropriate differential gear ratio depends on the vehicle's intended use, engine characteristics, and desired performance balance between acceleration and top speed.
