I have a couple cases of the old Mobil 1 0w30 Racing oil and was wondering if it was ok to use in my 07 Mustang GT w/ 24 valve 4.6 V8? This car specs 5w20. Im currently running Mobil 1 Advanced Fuel Economy 0w20 for either 6 month/ 7500k interval. Could the Mobil 1 racing go even longer?