New Yaris MPGs

[Synyster]

Is it unusual for new cars to get lower than advertised mpg until the engine "breaks in"?

Few weeks ago I picked up a brand new 2015 Yaris 1.5 automatic. My job requires me to drive a lot so I had to have an economical car. After few tanks, I'm really disappointed with mileage. Usually 28-30 mpg with 70% city 30% highway with 90% in Eco mode. Sure, I live in Wisconsin and we have really cold winters, but still ... From what I'm seeing here on the forum, everybody get much better fuel economy.

Before Yaris I drove a 2009 Honda Fit/Jazz and I averaged 38 mpg combined in same conditions. Recently my rental was Nissan Versa Note; during few weeks of driving it, my average was 33 mpg. I bought Fit used with 45,000 miles and Versa already had 30,000 miles when I got it from Enterprise, so I'm not sure what mileage they were getting when new.