I think the main reason race cars dont use them ate is because the engine gets rebuilt after every race, I know on the audi my oil return line had to be replaced and I was doing mobile one synthetic every 3k miles on the nose, I mean for $90 I thinks its good insurance after having to replace 2 turbos on my audi. Coking does happen even with the most advanced oils and and water cooled turbos, and when you think how hot the oil gets specifically from the turbo and how vital it is for the turbo to work why even risk it, especially on a modified car, if your going to spend money on it, why not have that inch of safety there. Its not like its going to hurt anything by having it.


oh and on the S4's and TT's they dont have a turbo timer as such, but they do have an aux oil pump that will continue to pump oil through the turbos after the car is shut off until the ecu is satisfied that it is cool enough.