I was thinking so, but my 3k-5k mile point came right as winter was rolling in so my mileage never really dropped. I guess that magic mileage point where break in is done and better mpg come happened at the same time as winter fuel so I never really saw a a change. That's good news for me, I've been happy with my mileage all along, so that should only mean better things to come as the weather warms up.