BMW Motorsport 3.85 Ring and Pinion Gear Set – E46 M3 / E60 M5 / E63 M6

Looking for a proven way to boost acceleration without adding stress to your BMW’s engine or drivetrain? The BMW Motorsport 3.85 Ring and Pinion Gear Set is one of the most effective performance upgrades available for the E46 M3, E60 M5, and E63/E64 M6.

By switching to a shorter final drive ratio, like 3.85:1, you increase rear-wheel torque by approximately 6%, delivering noticeably quicker acceleration and improved throttle response in every gear. This upgrade is ideal for sharper launches, faster corner exits, and stronger pulls—without compromising drivetrain reliability.

Unlike engine modifications, a gear ratio upgrade transforms your BMW's driving dynamics without increasing heat, wear, or strain. The ring and pinion act as torque multipliers, helping your engine reach its power band sooner and making your car feel more powerful—especially in street or track conditions.

Key Benefits:

• Improves Acceleration Without Adding Engine Stress
• 6% Increase in Rear-Wheel Torque Output
• Perfect for Street or Track-Driven BMWs
• More Effective Use of Gearing in Corners and at Speed

Real-World Example – 2004 E46 M3 (6-Speed, 275/35-19 Tires):

• 4th Gear @ 40 MPH:
  • 3.62 Ratio: ~2,250 RPM
  • 3.85 Ratio: ~2,350 RPM
• 6th Gear @ 70 MPH Cruise:
  • 3.62 Ratio: ~2,650 RPM
  • 3.85 Ratio: ~2,800 RPM
• 5th Gear Top Speed @ 8,000 RPM:
  • 3.62 Ratio: ~175 MPH
  • 3.85 Ratio: ~165 MPH

These changes demonstrate how a shorter final drive enhances acceleration while maintaining highway drivability.

Installation Notes:

This is a genuine BMW Motorsport ring and pinion set only. Installation requires professional setup inside your existing differential housing. BMW does not supply rebuild components (bearings, shims, etc.), so we recommend using a shop experienced in BMW differential service.

If your car has over 60,000 miles, consider a full differential rebuild.

Vehicle Fitment:

• 2001–2006 BMW E46 M3
• 2004–2010 BMW E60 M5
• 2004–2011 BMW E63 / E64 M6

BMW Part Numbers:

• 33108437888
• 33-10-8-437-888
• 33 10 8 437 888
• 33.10.8.437.888