I pulled the intake pipe off of the throttlebody for the first time ever today at 75,000 miles. I've heard reports of TLs with half my mileage with a dirty oily intake tract. Mine is spotless. No dirt whatsoever, and no oil. I was wondering if the lack of oil in the intake tract could be from using the Amsoil ACD SAE30 for most of the car's life?? I've never seen something this clean after this many miles. Any thoughs on the oil being a factor?