MAHLE 4285MS-15-1 Performance Piston Ring Set Single Cylinder 4.285" File Fit 1.5/1.5/3.0mm

The MAHLE 4285MS-15-1 is a single-cylinder performance piston ring set engineered for a 4.280" + .005" (4.285") bore diameter with ring widths of 1.5mm / 1.5mm / 3.0mm in a standard tension, file fit configuration. This set contains rings for one cylinder, making it ideal for selective replacement or custom engine builds requiring individual cylinder fitment.

MAHLE's MS-series piston rings are developed using advanced piston ring simulation and computer modeling tools, resulting in rings that reduce friction and improve combustion efficiency. The ultra-flat ring flanks ensure maximum ring-to-piston groove sealing for superior compression retention.

Ring Construction:

• Top Compression Ring: Positive twist ductile iron with barrel face and plasma-moly inlay for reduced wear and improved break-in
• Second Compression Ring: Reverse twist tapered face cast iron for effective oil scraping and sealing
• Oil Control Ring: 3-piece standard tension design for reliable oil management

Key Specifications:

• Bore Size: 4.280" + .005" (4.285" total)
• Ring Widths: 1.5mm (top), 1.5mm (second), 3.0mm (oil)
• Tension: Standard
• Fit Type: File Fit — end gaps must be custom-fitted to application
• Quantity: Single cylinder (3 rings)
• Part Number: 4285MS-15-1

File fit rings require the builder to manually fit the end gap to the specific bore and application. This allows maximum flexibility for performance builds where precise gap tolerances are critical. MAHLE's MS-series rings are a trusted choice among professional engine builders and motorsport teams worldwide.