Hello - my understanding is that the thermostat on the N14 opens at 105C automatically. How are tunes able lower coolant temps? Is there a electronic control for the thermostat as well? I noticed there seems to be 2 connectors on the thermostat, one that goes to the temp sensor and another that seems to go somewhere else on the other side of the thermostat.

 

The temperature control is electronic and controlled by the ECU. When you get a tune, the temperature control target is changed, allowing for a lower operating temp.

 

Why lower coolant temps? It's designed that way for a reason (water and fuel diluted in oil).

 

The original Mini programming for the thermostat is 225°F. Later, Mini reduced the target temperature to 190°F when in "Sport" mode. Most tuners will adjust the thermostat target to 190°F at all times. Running more boost creates more temperatures, and a cooler thermostat target will keep engine temps in check.

 

I fully understand the aim behind that, but there's some downside. Since many if not very most tunes will give a richer mixture the issue of oil dilution (fuel) is even raised. Increased oil temps and extended daily distances will help, as well as shorter OCIs. It has its advantages to run a little hot.