Originally Posted by Focus YBTC
Some low RPM torque is definitely lost in my car when running on regular gas and it just doesn't run as smooth or as powerfully overall.
This is where the MPG gains can be had. If you somewhat hypermile staying at the lower rpm's with premium the car will work well enough to see gains of 8-10%, at least that has been my experience. If you don't make attempts to short shift and stay in the lower rpm range, the gains from running premium will be negligible. I go back and forth with my driving style, but still run premium all the time.