Originally Posted by michaelwb
Interesting. I played with the trip computer today, resetting it several times on the highway to see what MPGs I got at constant speed.
I stayed in the far right lane and kept my speed between 52 and 57 mph, letting the car slow down as it went up nearly imperceptible inclines and gliding as much as possible. My MPGs stayed around 45 MPG.
Perhaps it's my 18" Titanium wheels and 5-speed transmission. An SFE might do better.
My steady state MPG at 55 mph is around 47 mpg and I have the DCT and stock 17" tires. So you're pretty much right on. ZX3's mid-40's claim seems a little far fetched but steady state MPG at 45 mph is almost 60 mpg so if he's spending a lot of time on country roads around 45 mph then I can see it being possible.