IMP, that is. The Queen's gallon.
The wife and I drove up to the family townhouse in Osoyoos this weekend. I intentionally gassed up in Hope to make the ~500 km round trip in one go. This trip is ridiculously mountainous - BC hwy #3 is a notorious road - so getting a round trip in one tank is essential for making the trip "elevation-neutral". This tank also included some short drives to the movies, local wineries, etc.
The highest I have ever recorded is 36.2 MPG (Imp) on this trip, although I have only ever gassed up along the way - never in Hope there and back (never elevation-neutral). I usually go 12 km/h over the speed limit and drive it HARD up hills. (Usually in a big hurry to get out there). At some points I am in 2nd gear (automatic) at 5000 rpm for 5 minutes at a time on the big uphills.
This time:
-Inflated tires up to 40 psi
-Stayed within 3 km/h of speed limit
-Backed out of it on big hills to keep the revs down
-Used neutral on slight down hills to maintain speed when DFCO was slowing me down
-Used A/C on the downhills only (when I could). It was 28C today and the wife is preggers...so I didn't feel like getting punched in the face because of lack of A/C.
The result? 41.0 mpg. 6.9L/100km.
I think I will do some duct tape aeromods when we do it again in May and repost here.
EDIT: Here's a map for a visual.
http://maps.google.ca/maps?saddr=Old...ra=mrv&t=p&z=9