I've done over 700 in one tank in my Altima 3.5 (Oakville to Burlington, Vermont). And that wasn't hyper-miling - it was just steady-state cruising at just under 120 kph). And I know I can do a good deal better still in my Sonata - just haven't had the need to drive that far on a single highway trip yet. Considering the massive power advantage of those two cars, and considerable interior space advantage as well, I'm not doing cartwheels over 980 in one tank for the compact Mazda. It's good, sure, but not particularly noteworthy, IMO.
Jaeger