Parts for your 2011 Mazda Premacy-Thermostat

2011 Mazda Premacy thermostat — what it does and when to service it

Per Mazda’s factory Workshop Manual for the CW-series Premacy/Mazda5 (Cooling System – Thermostat) and the Mazda Electronic Parts Catalogue for CW models, the 2011 Mazda Premacy is fitted with a wax‑pellet mechanical thermostat located in the thermostat housing at the engine’s coolant outlet. Genuine listings show market/engine‑dependent part numbers in the LF**‑15‑171 series for petrol variants and corresponding R2**‑15‑171 series for diesel, confirming this model absolutely uses a thermostat.

The thermostat in a 2011 Mazda Premacy is the quiet achiever of the cooling system. It helps the engine warm up quickly, then holds temperature steady by opening and closing to meter coolant flow through the radiator. That means better fuel economy, lower emissions, happier heater performance on a cold morning, and longer engine life. When it’s working properly, the gauge climbs smoothly to the middle and pretty much stays there—no dramas.

On this model, the thermostat sits in a compact housing on the engine, and it’s matched to a specific temperature rating. Sticking with the correct spec (as per the Mazda manual or EPC) matters