...understand that your motor is still pumping hot exhaust into the turbo...the only way that turbo is going to cool down is with the car off...if your running stock boost and such...then you dont need one (not like you need one at all). if you change your oil on a regular basis (2months/2500miles for me) then you will be fine...a TT is a waste of money. invest in an aftermarket oil cooler or something if your wanting to preserve your oil life.