Dawn

We bought a Ford Edge in April and are getting gas mileage as expected. I drive about 50% highway and 50% town and get 26 or 27 mpg. We recently took a trip were we were on windy hilly roads, so we only drove about 58 mph. We got 32.8 mpg on that trip. I have noticed that my edge gets the best mileage at around that speed. We also have the black soot in the exhaust pipes and our Ford dealer said it was nothing. Anyone not having this issue so that I would know this is not normal?