I just picked up my 2500 gas. In the manual it states to use 93 octane (premium) for best engine performance and best MPG. Ive read this whole thread and I am confused on if majority are using reg unleaded (87 octane) or premium. Pricing here in Cincinnati is on avg 1.99/ gal vs 2.39/gal. Obviously if i am towing i would use 93, I am just wondering if reg is ok or comparable in performance.