Mahle 41858CP Engine Piston Ring Set

Engine Piston Ring Set Overview

Mahle 41858CP is a premium engine piston ring set built to match standard bore applications with a 4.000-inch bore diameter. It uses carbon steel top and second rings, a stainless steel oil ring assembly, and a plasma-moly face coating for controlled friction and wear resistance.

Compatible with a wide range of GM truck, SUV, and performance applications, this set is specified for engines that require shallow-groove oil ring construction and standard oversize dimensions. Mahle 41858CP is a direct choice for rebuilds where ring sealing, oil control, and service life matter.

Key Features

• 4.000-inch bore diameter for standard bore engine applications
• Premium-grade piston ring set for rebuild work
• Plasma-moly face coating for reduced friction at the ring face
• Carbon steel top ring and second ring for strength and stability
• Stainless steel oil ring assembly with shallow groove design
• 1.50 mm top and second ring thickness with 3.00 mm oil ring thickness

Detailed Description

Mahle 41858CP is engineered around OE-driven piston ring requirements, with a focus on lowering friction, reducing ring mass, limiting engine oil consumption, and supporting longer service life. The ring package combines carbon steel compression rings with a stainless steel oil control assembly to provide the sealing and oil management needed in high-use gasoline engines. This makes it a practical option for Chevrolet Silverado 1500, GMC Sierra 2500, and Cadillac Escalade rebuilds, along with other listed GM applications.

This part cross-references Hastings Piston Rings (e.g., 2M4860) and Sealed Power (e.g., E921K) for the same application. The 41858CP part number is also useful when verifying the correct ring set against engine specifications before assembly.

What It Is Used For

• Restoring cylinder sealing after engine wear
• Reducing oil consumption caused by worn rings
• Improving compression retention during rebuilds
• Addressing blow-by from tired piston ring packs
• Replacing damaged or fatigued ring components in compatible engines

Installation Notes and Tips

Verify bore diameter, ring thickness, and groove style before installation. Confirm that the engine uses a standard 4.000-inch bore and shallow-groove oil ring configuration, and compare the ring dimensions to the original parts during teardown. Proper ring end-gap measurement and cylinder preparation are essential for correct sealing and long-term performance.

Quality Assurance

Mahle positions this piston ring set as an OE-driven, technically advanced replacement built to support friction control, oil management, and service life in rebuild applications. The 41858CP part number identifies the exact ring set specification for matching against the listed fitment.