Precisely. I didn't say follow the manual I said call Ford Performance. If you do so I'm pretty sure they will recommend 5w50 for track use. This is nothing new, TMO members have been using 5w50 in their 5.0's dating back to 2010.The original poster has a 2011 GT NON Track Pack. He modified the car with added coolers but was asking about oil viscosity. Because the 2011 NON Track Pack GT's ONLY call for 5W-20, should he not consider higher viscosity?