I'm getting what you are both in summer and winter. I notice about a 10% drop with all of our other cars in the winter, so makes sense I'm getting ~29 currently with the 10% ethanol. (70mph freeway). All stock, Subaru synthetic oil.It must be a hugh difference with 99% highway. 63 miles each way to work. My wife drives within 10 of the limit and always get 29-33 average. She has never gotten less than 29 on a tank doing it long hand. We went from Kent Island Md to Ocean City this summer running a straight run @ 55-60 mph non stop and got 34. Winter gas is still at 29.4-30.9.