I noticed that for 2006 Volvo reports 26 MPG hwy and 19 MPG city, while for 2005 they reported 24 and 18 respectively. I can't tell what they did to get those two extra MPGs. Mechanically everything is identical. Is this just how they measured it?

Just an update, I think the gas mileage has improved on my 2005 XC70. I've made trips up to MD from S.E. VA and usually only got around 24.5 MPG. This time I got 26.2 MPG up and 27.3 MPG on the way back. Very nice for a large wagon with a turbo charger. I set the cruise at about 72 MPH, because I notice that once you hit 75 mileage seems to taper off.