Piston Ring Set 4.045 1.5 1.5 3.0mm

The MAHLE PISTONS Piston Ring Set 4.045 1.5 1.5 3.0mm (Part No. 4045MS-15) is a file-fit performance series piston ring kit engineered for eight-cylinder engines requiring precision ring clearance and consistent sealing. This ductile iron ring set features plasma moly coating on the compression rings and is designed to deliver reliable blow-by control and oil consumption management across demanding operating conditions.

The 4.045-inch bore diameter with 1.5mm top ring, 1.5mm second ring, and 3.0mm oil ring thickness represents a balanced specification for standard tension applications. The plasma moly treatment on the compression rings reduces friction and enhances ring-to-bore contact, critical factors in high-revving eight-cylinder engines where heat and load concentrate at the ring package. File fit designation means these rings require light honing or filing to achieve proper gap clearance—a procedure that ensures optimal sealing and prevents ring flutter or excessive blow-by.

This ring kit is suitable for engine rebuilds, top-end overhauls, and performance restorations where bore diameter matches 4.045 inches. MAHLE's piston ring sets are favored by engine builders and machine shops for their consistent metallurgy and dimensional accuracy. Installation requires proper ring groove inspection, hone preparation, and gap verification to ensure the rings seat correctly and deliver the compression and sealing performance the engine design demands.

Piston ring selection is a critical rebuild decision—improper ring fit or material choice directly impacts cylinder pressure, oil consumption, and engine longevity. The MAHLE 4.045MS-15 set combines proven ductile iron durability with plasma moly surface technology to support both street and performance eight-cylinder applications where bore size aligns with this specification.