Race Coolant Thermostat for Mercedes-AMG M157 / M278 (BiTurbo V8)

Keep your cool — even when the boost is up.
The Race Coolant Thermostat is an essential upgrade for AMG and performance Mercedes-Benz models equipped with the M157 (5.5L BiTurbo) and M278 (4.7L BiTurbo) engines. Designed to open at a lower temperature than the factory unit, this thermostat improves thermal management, helping reduce engine temps under load, prevent heat soak, and enhance reliability for tuned or aggressively driven vehicles.

Whether you’re pushing higher boost or just want peace of mind on hot days, this is the cooling upgrade your AMG deserves.

✅ Features & Benefits:

• Lower Activation Temp
  Opens earlier than stock (typically 8–12°C / 15–20°F lower), helping coolant circulate sooner and reducing peak engine temps.

• Optimized for Performance
  Perfect for vehicles running ECU tunes, upgraded turbos, or operating in hot climates where cooling efficiency is crucial.

• Direct OEM Replacement
  Installs just like your factory thermostat — no modifications or special tools required.

• Improves Engine Longevity
  Reducing operating temps helps protect internal components from thermal stress, especially during high-load conditions.

• Durable, Motorsport-Grade Construction
  Built with high-temp resistant materials for consistent performance and long service life.

📈 Performance Advantages:

• Reduces engine temps by 8–12°C (15–20°F)

• Minimizes heat soak and timing pull in high-performance applications

• Supports more consistent power delivery in tuned or modified setups

• Enhances overall engine reliability and cooling system efficiency

💬 Why Upgrade?

The M157 and M278 BiTurbo engines are built for performance — but when pushed harder with tuning, higher boost, or hot ambient temps, they generate a lot more heat than the factory cooling system was designed for. This Race Coolant Thermostat ensures your engine stays cooler, more consistent, and better protected, especially during aggressive driving or long pulls.

⚙️ Vehicle Compatibility:

M157 (5.5L BiTurbo AMG Models):

• E63 / E63S AMG (W212)

• CLS63 AMG (W218)

• S63 AMG (W221)

• ML63 / GL63 AMG (W166 / X166)

M278 (4.7L BiTurbo Models):

• S550, CLS550, E550, GLE550, GL550, and more

• Any model equipped with the M278 V8 BiTurbo engine

🔧 Installation:

• Direct-fit OEM replacement

• Works with factory and aftermarket coolant systems

• Professional installation recommended for best results

🏁 Cooler Running. Smarter Performance.

Give your AMG or BiTurbo Benz the cooling confidence it needs. Upgrade to our Race Coolant Thermostat today — and keep temps in check, power consistent, and reliability rock-solid.