I am a little curious though about these numbers... The 2004 V6 4Runner has 2 individual estimates for 23.0 MPG and 13.7 MPG giving the average if 17.4. The 2007 V6 4Runner has 3 estimates, 2 over 20 MPG and one at 17.5 MPG giving a higher average. I like the fact of using real world vehicles/drivers, but without a minimum collection of data points, these numbers are just as vague as the original EPA estimates.
I am also curious how the same engine/exhaust combination can be so poor in greenhouse gases and air-pollution score in 2004, but can be much better in 2007... If there is some re-programming to be done, I'd do it to make it more environmentally friendly.