BMW S85B50 MAHLE Motorsport Conrod Bearings | E60 M5 | E63 M6

These are the MAHLE Motorsport rod bearings for the S85 — made in the UK by the same people who make F1 bearings, and the same bearings used in Le Mans, NASCAR, MotoGP, WRC, and DTM. On an engine where rod-bearing wear is the known bottom-end weak point, that pedigree is the point.

Nominal optimal clearance of 54 micron (43–57 micron range), calculated with MAHLE Motorsport's proprietary software that predicts housing swell, bearing loads, oil-film thickness, and power loss — the same software MAHLE uses to design its Formula 1, Le Mans, NASCAR, MotoGP, WRC, and DTM bearings.

Bearing construction:

• High-strength steel back with a cast bronze substrate, finished with a lead-indium overlay (originally known as VP2). This structure gives higher fatigue strength and better conformability than other race bearings, and the same material still runs in race engines across every major series.
• Not to be confused with "tri-metal" bearings: those are typically sintered with a lead/tin overlay, which gives lower fatigue strength.

Laser marking:

• Every MAHLE Motorsport bearing is laser marked. Traditional stamping can distort the bearing and hurt heat transfer into the housing, which leads to failure.