MAHLE 40668CP.040 Premium Plasma-Moly Piston Ring Set 3.790 in. Bore 6-Cylinder

The MAHLE 40668CP.040 is a premium plasma-moly piston ring set designed for 6-cylinder engines with a 3.790-inch (96.27mm) bore at 0.040-inch oversize. Part of the MAHLE Original Premium line, this set delivers OEM-grade quality and installer-friendly design for engine rebuilds and overhauls.

MAHLE Original piston ring sets are pre-lapped at the factory, allowing them to seat immediately and virtually eliminating traditional break-in time. Ring materials, coatings, and ring tension are all precisely engineered to minimize friction and maximize service life.

Key Features:

• Plasma-moly coating on compression rings for superior wear resistance and reduced friction
• Barrel-faced top compression ring contact area for more efficient sealing and reduced blow-by
• CNC-controlled gap chamfer on compression rings to optimize compression and minimize combustion gas leakage
• Reverse twist intermediate ring design for improved groove side sealing, with taper race machining to enhance cylinder wall contact
• CP-20 oil ring assembly featuring an exclusive 20-degree ear angle for superior side sealing against the cylinder wall
• Chemically polished oil ring expander for enhanced oil drain-back performance
• Ring dimensions: 5/64 in. top compression, 5/64 in. intermediate, 3/16 in. oil ring
• Bore size: 3.790 in. (96.266mm) — 0.040 in. oversize
• Sold as a complete set for one cylinder (6 sets required for full 6-cylinder engine)

MAHLE is a global leader in engine component manufacturing with deep OEM ties, ensuring this ring set meets or exceeds original equipment specifications. The UPC for this part is 027067083913.