Gas Mileage on Honda Element!!?

Question

So, I bought an '03 Honda Element recently, and all the online reviews I read said that it got really good gas mileage (for its size, that is.) But lately I've only been getting about 19 miles to the gallon.. Is this normal?

Also, when I go above 55/60 mph, my windows make a whistling noise, like they're down or something (even when they're rolled up all the way).

Does anybody else with an Element have these problems?

Answer 1

I calculated 15 around town and 19 on a 1000 mile road trip on cruise control @ 73 mph

 

What am I doing wrong here?