2004 Corolla vs. 2004 Matrix

[Erdrick]

I currently drive a 2004 Corolla (auto). I bought it for $5200 with 120k on the odometer. I average from 37-45 mpg. The more time I spend in the driver's seat, the high the number. The more my wife is strapped in, the lower the number falls. I currently put 12-14k on it per year. That will change to a more reasonable 3k or so per year (we are moving).

I have a coworker who is selling his 2004 Matrix (auto). He is selling it for $4000 with 90k on the odometer. I have noticed that the Matrix's numbers on fueleconomy.gov are fairly low compared to the Corolla -- for every model year.

As these are essentially the same car with different body styles, the different numbers confuse me. I would like to think that it is just driving styles between the two types of people who purchase each of the cars. Can anyone weigh in on why the numbers on the Matrix might be low? I am also thinking about selling my Corolla, and am confident that I could get more than what I paid for it. Getting the Matrix dirt cheap would just be icing on the cake... especially since I prefer it's superior usability with the lay flat seating.