it's still dissapointing to me. There are plenty of other small 4 cyl. turbos that get close to 30 mpg on the highway. Even huge 5-6 L V8's get 25 mpg (like the pontiac G8) on the highway! It's not like your turbo is spoolin away much when you're driving @ 2800 on the highway. just doesn't make sense to me. This has always been a sour spot for me with Mazda's- my 2.0 L Protege5 never even got 30 mpg on the highway.
The answer is gear ratios. Had this problem with my old '03 Protege, when it sat close to 4,000 RPM on the highway. I would prefer 6th in the MS3 to be taller since all it is to me is a cruising gear.
The reason 6th in a Corvette or G8 yields great gas mileage on the highway is tall gearing and an abundance of low-end torque. They can putz around below 2,000 RPM and not break a sweat.