Originally Posted by vasillalov
This is awesome indeed! Impressive review as usual! A few notes:
* I am surprised that STETT did a completely new bracket for the oil filter housing. They could have simply use the two bolts on top of the oil filter housing.
* Having a larger oil cooler also increases the total capacity of the oil system. More oil capacity means that it will take longer for the oil to get contaminated and beaten up from the normal driving.
* The larger oil cooler core is great for shedding temperatures quickly, but in my opinion, it is the thermostat that has the biggest effect on the oil temperature. I strongly believe that with a 180F degree thermostat, the stock oil cooler will perform close to what you are seeing. It won't be able to shed the temps as quickly as the STETT one, but the overall temps will be the same or close to it.
* I wonder how the lower oil temps will affect the engine efficiency. If I am not mistaken, our engines are designed to achieve maximum efficiency at over 200F.
Do you know if the stock thermostat can be replaced without having to purchase an aftermarket oil cooler?
Vasillov, I believe they thought about using the stock bracket location at first, but in the end found this to be the better design. Maybe STETT can chime in on that?
It is hard to say how the stock cooler would respond with a lower thermostat and I have thought about that too. The problem is that the stock oil cooler ducting is remarkably restrictive. I personally think that ducting should never have come with the car to begin with.
I think the 180F thermostat in non-winter conditions will allow you to operate near the 200F threshold you mention. I am honestly not sure what to believe from BMW now. I think their agenda is not always performance or we would have 260F oil temps so easily.