Sourced from HEPU, this thermostat coolant (TM1138) combines precision engineering with durable materials to meet the demands of everyday driving and extended service intervals. Technical specifications — Opening Temperature [°C]: 87 °C, Supplementary Article/Supplementary Info: 35 — are verified against the OEM data sheet to guarantee fitment accuracy and performance parity with the original equipment. Verified to fit AUDI, SEAT models. All compatibility data is cross-checked against the TecDoc database — select your vehicle to confirm the part matches your specific engine and year. This part supersedes original equipment references: 03L 121 111 AD, 03L 121 111 N, 350529, 4006167 and 13 more. Matching these numbers confirms a like-for-like replacement with no loss of function. HEPU 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 from our UK warehouse with a 30-day money-back guarantee and free hassle-free returns.