[HiFlow5 0]

Conventional oil is fine as long as you keep with with your 3k mile/ 3 month oil changes. I an running 10W40 right now, and during the hot summer months, and 10W30 goes in right before storage in the winter. 20/W50 might be a little much, unless your all out racing the motor when it sees excesive heat and constant use. 20W50 will also make the car run slightly rougher, and eat up a few HP due to the thickness of the oil in the crankcase.