You don't necessarily have to use premium. The engine computer will adjust timing to eliminate pre-ignition/piinging. You'll lose a little bit of power but nothing very noticeable. Your call: lose some power or money. Try a tank of 87 grade and see if the difference is worth the cost.I think it's listed at 20 mpg hwy?!?! I don't expect too much in the form of MPG. I do wish it didn't recommend premium, as if it didn't, I wouldn't put any in, but since it does, I will, begrudgingly.