MAHLE 41489CP.040 Perfect Circle Premium Piston Ring Set Over - 0.040

The MAHLE 41489CP.040 is a Perfect Circle Premium piston ring set featuring a 0.040-inch overbore specification, designed for engine rebuilds and re-ring jobs demanding OE-quality materials and precision fit. MAHLE Original — formerly branded as Perfect Circle — has been trusted by professional engine builders for over 100 years.

Key Features:

• Premium compression rings — moly or chrome-faced top rings for long-lasting performance under severe operating conditions
• Barrel-faced contact area on compression rings for efficient sealing and reduced blow-by
• Reverse-twist intermediate rings with taper-face machining for enhanced groove-side sealing
• 3-piece CP-series oil ring assembly with a stainless steel expander and two chrome-faced steel rails for superior cylinder conformability
• Installer-friendly design — engineered so rings cannot be installed incorrectly, saving installation time and reducing errors
• Pre-lapped from the factory to seat immediately, virtually eliminating extended break-in time
• High tensile and yield strength with low ring mass for stress resistance, minimal groove pound-out, and long service life
• Optimized ring tension for reduced friction, improved oil economy, and excellent blow-by control

The CP oil ring assembly features an exclusive 20-degree ear angle design that provides maximum side sealing against the cylinder wall. Ring materials, coatings, and tension levels are all application-optimized for consistent, long-term reliability. This set is sold as a complete ring set for one engine. Ideal for overhaul, performance rebuild, or re-ring applications where exacting tolerances and proven OE-level quality are required.