Gas Mileage is what?

I was thrilled to own my first SUV, a 2006 Tucson. Loved the style, felt nice and tight, interior just the right size and, oh yes, the misses loved it. Can fold the back seats down, put a pad in the back with pillows and take the dogs out with us. At 4,000 miles called the dealer's service dept. and asked if they would look at the car; it really got poor gas mileage. I was told that will get better as the car is broken in (I've owned a dozen new cars in my life and yes, that's normally the case). At 10,000 miles it still couldn't get better then 19.8 MPG (calculated with gas receipts and mileage figures, not the on-board computer). Now I was told by the dealer (Atlantic Hyundai, West Islip, N.Y.) that's considered average. I asked, what happened to 22 MPG in-town and 26 MPG highway on the window sticker? Oh, they were just estimates I was told. Just as a comparison, 10% plus or minus, is used in the business world when making estimates and 19.8 is sure a far cry from 26 MPG. I drive 38 miles to work each way, all highway miles, with cruise on at between 55 and 60 MPH. I have 35,000 miles on the car, have it serviced on a regular basis, and still get 19.8 MPG. NO MORE HYUNDAIS, NOW JUST HONDAS OR TOYOTAS.