MAHLE 40139.030 Engine Piston Ring Set +0.030" Oversize OE Replacement

The MAHLE 40139.030 is an OE-quality engine piston ring set sized at +0.030" oversize, engineered to restore compression, reduce blow-by, and minimize oil consumption during engine rebuilds and overhauls. As one of the world's largest OE piston ring manufacturers, MAHLE designs every ring set to meet or exceed original equipment specifications for fit, form, and function.

Key Features:

• OE-Driven Engineering: Designed to OE requirements, reducing friction and ring mass while minimizing engine oil consumption and extending service life
• Pre-Lapped Construction: Rings are pre-lapped to seat immediately, virtually eliminating break-in time and simplifying installation
• Optimized Ring Materials & Coatings: Ring tension, materials, and surface coatings are application-matched for reduced friction and long-term durability
• Barrel-Faced Compression Rings: Upper compression rings feature a barrel-faced contact area and CNC-controlled gap chamfer for improved compression efficiency and reduced blow-by
• Reverse-Twist Intermediate Rings: Second rings use a reverse twist design for superior groove-side sealing and taper-race machining for enhanced cylinder wall contact
• CP-20 Oil Ring Assemblies: Feature an exclusive 20-degree ear angle for optimal side sealing within the piston oil ring groove, plus a chemically polished expander for improved oil drain-back
• +0.030" Oversize: Sized for bores that have been machined 0.030 inches over standard — confirm your bore size before ordering

MAHLE piston rings are the trusted choice of professional engine builders worldwide, offering installer-friendly design and the same technology found in OE production engines. The 40139.030 ring set delivers reliable sealing performance and long service life when installed as part of a proper engine rebuild.