So is it possible my 28i in particular is not functioning properly? The weekend trip I took my average speed from the trip stat was just below 50mph. I used mostly Eco Pro, with accumulated mile bonus of +70 miles out of a total 670 miles travelled. Yet the gas mileage at the end barely reached 25mpg. On my way back from Maryland to New York, I drove 285 miles without any traffic on the interstate. Me and my wife was the only occupants and we were not carrying cargo. I used Shell 93 Oct fuel. I wanted to push for the best fuel economy ratings so I was very easy on the gas, other than maybe a dozen sprint to get around slow moving cars. My car is a 2014 with 21K miles and just services last month.
