I bought an optima ex a few weeks ago and now have 1200 miles in it. Very disappointed in mpg so far. Best it will do is 32-33 mpg at 60-65mph on a flat open highway. Sticker says 37mpg. Has anyone else had this situation? The salesman I bought the car from tells me it just needs to break in, bit I don't see it improving. I traded a 2015 ex with the 2.4 L and it did 35+mpg on the same roads. Not impressed so far.