|
I made the 165-mile trip to and from my parents' house almost every week this summer. The best mileage going was 28 MPG and the best returning was 40.4 in my Forester. According to usclimatedata.com, there is a 5,147-foot climb overall. A decade ago I used to coast down a canyon in my Prelude and coast back up the other side. With my Subaru I usually coast in gear. I am not taking those corners quickly. With perhaps a 5% grade I can maintain speed in neutral, while I would need to accelerate in gear. With perhaps a 6% grade I can maintain speed in gear, but I have accelerated 40 MPH in neutral time and time again.
I do not know how long these slopes are, but the difference of 0.3 GPH and 0 downhill is negligible compared to coasting up the other side and driving in gear. There are other hills that are relatively flat at the bottom. How far would an additional 40 MPH of momentum take me on level ground?
As I have mentioned in other posts, the highway patrol like to sit and wait for me on those hills, and once I hit a deer or an elk. Mythbusters drove cars into a rubber buffalo at different speeds. At high speeds the buffalo removed the top half of the car.
|