In an automotive braking system, front and rear calipers differ significantly in design and function due to the different forces and roles they bear.

1. Different Brake Force Distribution  

- During braking, the vehicle's center of gravity shifts forward, and the front wheels bear approximately 70–80% of the braking force, making them the primary source of braking.  

- The rear wheels provide only 20–30% of the braking force, helping to maintain vehicle stability and prevent skidding or loss of control.

2. Different Piston and Structural Design  

- Front calipers: Subject to higher loads, they commonly use fixed calipers with two, four, or six pistons. They are larger and provide stronger clamping force.  

- Rear calipers: Subject to lower loads, they are mostly single‑piston floating calipers, which are smaller and simpler in construction.

3. Different Functional Integration  

- Front calipers: Responsible only for service braking, with a simple structure focused on braking performance and heat dissipation.  

- Rear calipers: Often integrate the parking brake / electronic parking brake (EPB), providing parking hold functionality, which makes their internal structure more complex.

4. Different Heat Dissipation and Materials  

- Front wheels: Generate more heat during braking, requiring better heat dissipation, higher strength, and lightweight properties. High‑performance aluminum alloys are commonly used.  

- Rear wheels: Generate less heat, so the demands on heat dissipation and materials are relatively lower.

5. Different Maintenance and Wear  

- Front brake pads and discs wear out faster and have shorter replacement intervals.  

- Rear wheels: In addition to regular maintenance, the parking brake mechanism, motor, and return function also need to be inspected.