In addition to Mr. Meehan’s valid comments, I want to add that–in the case of the actual OP, rather than octavio 09–it was stated that 26 mpg was achieved at 70 mph. If I am not mistaken, the “offical” gas mileage figures are calculated at a lower speed–perhaps 55 mph, perhaps 60mph–and while I definitely don’t think that 70 mph is an excessive speed on a good interstate highway, that is NOT the speed that someone should be driving at if they are interested in maximizing their gas mileage.
Additionally, I can verify that gas mileage does increase once the engine is “loosened up” a bit. Back around December, after my odometer passed the 90k mark, my gas mileage increased by about 1/2 mpg, and recently it increased by another 1/2 mpg. Since my daily drive does not vary at all, and since my driving style is also a constant, I believe that the engine has finally “loosened up” sufficiently to give me a small mileage boost. And, since it still burns no oil between changes and still retains excellent power, I think that I am in the “sweet spot” in terms of performance/gas mileage/engine wear.
Ergo–good maintenance really does pay off, and you will be rewarded with better gas mileage in a few months, or in a few years. I think that an overall figure of 26 mpg (with a highway figure of ~29mpg) is pretty good for a 212 hp six cylinder engine in an AWD vehicle like my '02 Outback.