@JJW
the Xa and Xb should have identical drive-train as our Yaris' but the Yaris has less drag and a higher final drive (should be better freeway MPG)
I have gotten almost the same mileage as you with my sedan. I think things have a allot to do with your specific commute and what part of the country you are in. I am in SoCal so 10% ethanol, hot climate(A/C on), lots of traffic and San Diego for me which has lots of hills.
signed quest for 50
