Here in DC, you never know when you are going to run into a solid wall of traffic, so it seems most everyone just hits the gas on any open stretch of highway. Since I got the Civic, and keep it just under 70mph and am getting around 42mpg on average at that point. When I see the wall coming up, I start costing, and try to keep the speed between 20-30. This sends my mileage on the rebound. On big down-hills, I try to get the engine to cut out, and cost with the engine off. Currently getting 45mpg with a couple of 5000RPM runs merging into traffic, but quickly getting into "coast" mode. Gotta love the ASSIST. I'm really enjoying the car. I'm all smiles looking at my mileage meter. My co-worker with the HEMI powered RAM is asking more questions everyday, and his wifes Taurus might end up for sale soon.