As an optional engine instead of the 3.7 V6. Expect a high horsepower GT350 or GT500 in 2016. The turbo 4 will be the base engine for Mustangs sold outside of north America. At north of 300 horsepower the little turbo 4 will be nothing to sneeze at. My money is on the 2.3 Mustang to kick the ever loving shit out of…