I suspect that since the automakers have knowledge of what the test routine is for EPA, that perhaps they "tune" the engine and transmission of the high FE models to produce the best EPA results, which helps to sell the high FE models.
sounds like a good theory to me. my last 3 tanks would have me at 29% above combined epa.
let's have a look at basjoos' numbers: he's about 20% above EPA @ lifetime mpg. if you just look at his 3 most recent tanks, roughly 62-ish, he's about 38% above.
and fredvx: 27% over EPA (2 tanks).
nothing outright conclusive, but it's good supporting evidence for your theory about epa & "efficient" cars.
Thanks for that chart metroMPG! Totally explains why my fuel average went UP after I STOPPED highway driving. With our 110 km/h speed limits in Alberta (and having to hit 115 to keep from getting run over) that totally explains why I could barely hit a 40 mpg average. I must have been get about 35 mpg on the highway during the winter! Yuck!
PS: I've heard that the Sprint/Firefly Turbos get WAY better highway mileage than the NA clones. Wouldn't mind testing a turbo setup with 1 or 2 pounds of boost for the city and then adjusting it to the stock 7 pounds for highway.
If I did a new one today with the new transmission, you couldn't compare it directly to the original, since it was made when the temps were 58 F.
In fact, I realized last night that my claim of 8.x% improvement with the taller transmission is faulty, because I based it on the colder ambient speed/mpg data. The actual transmission improvement is less.