Mosselman MSL 85C Low-Temp Oil Cooler Thermostat Upgrade for BMW S55 - M2 Competition (M2C) F87, M3 F80, M4 F82/F83 (CS/GTS) | Drop-In Plug & Play Billet |

Mosselman 85°C Thermostat for BMW S55 - a proven way to keep your S55 twin-turbo straight-six running cooler and more consistent on fast road and track. If you are seeing rising lubricant temps, heat soak or fading performance, this drop-in thermostat is the smart reliability upgrade for M2 Competition, M3 and M4 owners.

Key highlights

• Early-opening 85°C stat that reins in oil temperatures and stabilises heat management
• Typical operating band around 95 to 105°C depending on vehicle setup and conditions
• Helps avoid the 120°C-plus spikes commonly seen on factory hardware
• Ideal for mapped Stage 1 and Stage 2 cars, spirited road driving and track days
• True thermostatic control for quick warm-up and controlled temps once hot
• Direct-fit replacement - no coding required, no permanent modifications
• CNC-machined billet aluminium body for strength, durability and leak resistance

Why it works

The factory S55 setup runs hot. By opening at 85°C, the Mosselman unit brings the cooling circuit into play sooner, keeping oil within a far healthier window. You retain proper warm-up times, then benefit from more consistent temperatures during hard use. The result is improved confidence, steadier performance and reduced thermal stress on the engine.

Built to perform

Each thermostat is precision machined from high-grade alloy for longevity and a reliable seal. It is engineered as a plug-in replacement for OEM equipment, making it a clean, reversible upgrade for both daily-driven cars and track-focused builds.

Recommended sealing kit

For a perfect, leak-free install, add the installation kit:

• 2 x O-rings for the oil lines
• 1 x rubber oil filter housing gasket

Real-world results

We run this thermostat on our own S55 projects and it is consistently praised by our customers for lowering and stabilising oil temps, improving consistency on spirited drives and during track sessions, and delivering extra peace of mind on tuned setups.

Vehicle compatibility

• BMW M2 Competition F87 - S55
• BMW M3 F80 - including Competition and CS - S55
• BMW M4 F82 F83 - including Competition, CS and GTS - S55

Fitting and support

Professional installation is recommended. MJ Modifications offers fitting at our Warwickshire workshop. Request a quote at info@mjmodifications.co.uk.

Who is it for

Owners chasing stronger heat control for BMW M2C, F80 M3 and F82 F83 M4; track day drivers; fast-road builds; remapped S55 cars looking for dependable oil temperature control without sacrificing warm-up.

Search-friendly terms

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