When thermostat coolant performance matters, the HELLA 8MT 354 778-401 delivers — built to the same dimensional and material standards as the original part it replaces. The part is built to the following specification: Opening Temperature [°C]: 83 °C, Supplementary Article/Supplementary Info: 98. Each dimension is checked against the OEM reference to ensure the component seats and functions correctly first time. Compatible with MERCEDES-BENZ vehicles; use the vehicle selector above to confirm exact fitment for your make, model, and engine variant. Fitment data is sourced from TecDoc, the authoritative European parts catalogue. This part supersedes original equipment references: 003 203 31 75, 003 203 72 75, 003 203 78 75, 004 203 83 75 and 40 more. Matching these numbers confirms a like-for-like replacement with no loss of function. HELLA is a recognised supplier of automotive replacement components to independent workshops and dealer networks across Europe. All parts are sourced from authorised distribution channels and carry full manufacturer traceability — you receive exactly the same component supplied to professional garages and dealer workshops. If fitment or specifications do not match your vehicle, our technical team can help identify the correct alternative — use the vehicle selector or contact us with your VIN for a guaranteed-fit recommendation. Replacing worn components on schedule preserves your vehicle's safety, reliability, and resale value — and aftermarket parts from established brands deliver OEM-equivalent performance at a fraction of the dealer price. Every part is dispatched with tracked delivery and a 14-day money-back guarantee with hassle-free returns.

HELLA, founded in 1899 in Lippstadt, Germany, is a global automotive lighting and electronics specialist now operating as FORVIA HELLA. HELLA specialises in headlamps, rear lights, signal lighting, sensors, actuators, and electronic control units. As an OE supplier to virtually all major car manufacturers, HELLA products represent the cutting edge of automotive lighting and electronic technology. With 125+ years of innovation in vehicle illumination and electronics, HELLA is the definitive choice for high-quality lighting and electronic component replacements.