This is a MAHLE piston ring set sized for an 89.00mm cylinder bore, supplied as a three-ring-per-cylinder set (1.2mm compression ring, 1.5mm napier ring, 2.0mm oil control ring) built to MAHLE OE production tolerances for correct seal, oil control and compression when rebuilding the engine.
Fitment: BMW 5, 6 and 7 Series, X5 and X6, chassis F10, F11, F12, F13, F01, F02, F15 and F16 (also shared with Alpina B5/B6/B7 models on the same platforms), fitted with the twin-turbo N63B44 V8 engine, cross-referencing OE numbers 11257647123, 11257647125 and 11257649927.