fuel economy of 7.8 seems a bit high, especially if most of it was on the highway, but i'm not sure of the mileage on the car (nor the nature of driving it)...if i take the highway run home (400 series), that route is generally high 5s at 115-120 km/hr...as well, 100 km/hr with the 6 speed auto has the engine turning just over 2000 rpm (i think about 2150 if memory serves me correct...2500 rpm is bang on 70 mph ( almost 113 km/hr)...the 17" tires on my car exhibit the same result over large bumps, but are quite good for handling on "decent roads"...older pavement is quite noisy, but fresh(er) asphalt is silent...that likely has a lot to do with the tires, as i recall replacing a set of Pirelli tires on one of our previous Focus' with a nice set of Michelins and the noise reduction was quite significant (without really much of a penalty on handling).