Mosselman (MSL) F-Series BMW Oil Thermostat N54 / N55 / S55

MOSSELMAN OIL THERMOSTAT (MSL)
Includes gasket, O-rings, and titanium bolts. VIN required to confirm fitment.

The N54, N55, and S55 engines run hot from factory—often hitting ~120°C in normal driving. The MSL Oil Thermostat lowers the opening temperature to ~85°C, keeping oil temps stable in the 95–105°C range depending on model.

This means:

• Lower oil temps

• More consistent performance

• Better long-term engine reliability

Especially important for tuned or track-driven cars.

Why MSL vs. “always-open” solutions?
This thermostat is a real thermostat—not permanently open. Your engine still reaches proper operating temp in cold weather. CNC-machined from high-grade aluminum for durability.

Recommended Upgrade

• Plug-and-play install (≈30 minutes)

• Works in all climates

• Optional single or twin MSL Oil Cooler Kits available for heavy track use

Compatible Engines:
N54 • N55 • S55
(Fitment includes 1-Series, 2-Series M235i/M2, 3-Series, 4-Series, Z4, M3/M4, etc.)

If you’re running more power or pushing the car hard — this is the temperature control upgrade your engine needs.