Steep climbs and gentle descents

Weekly, I make a 180 mi. (290km) round trip on back-roads to visit Mom. With my C and fair weather I can get 80+mpg (2.9 l/100km, indicated) for the trip. Though traffic is always better on the early leg, mileage is always better on the return. One possible reason is the shape of many hills topping out at 1200’ (360m) elevation gain. Others have reported a sweet spot of (max?) 6% ascents followed by gentle descents, so I used Google Maps (+ terrain) and Earth to find 4 interesting loops near my route. This was more Autumn Sunday drive than test so I’ll admit to a lack of scientific rigor. It was windy, but traffic was light and temp was ~48F (9C). Start/End state of charge was 6 of 8 bars except as noted, and I used 1/4 of my seasonal grill block. I hoped to learn two things:

(a) Was a 10%+ climb really the mpg-killer that others have reported?

(b) With a 6% climb + gentle descent could I finally break the 90 mpg barrier? (I know others can reach 90+ mpg on flats with P&G at low speeds, but in Massachusetts we don’t have roads and/or traffic conducive to that. At least, that’s been my excuse.)

Loop 1 is longer (17.8 mi.) and taller (1500’climb, with 1325’ over 2.5mi.) than the others. The descent was the eastern slope of MA Rt.2 – aka The Mohawk Trail. I used full grill blocking for this descent, but it was just too much of everything.

(1) 1 pass: Ouch. 71.8 mpg (SOC = 5 at start and finish, 64% EV, 27 mph)

Loop 2 = 5.8 mi. with 450’ climb over 2.2 mi. (but 250’ over 1/3 mi). I had high hopes for this, as the roads are smooth, just 2 stop signs, and no cars. But the steep part doesn’t allow a good run at the base.

(2) 2 passes: 81.6 mpg and 78.8 mpg (78% EV, yay! – but oh that climb, 23 mph)

Loop 3 = 9.0 mi. with 360’ climb over 2 miles (but 250’ over 1/2 mile). I could get a run at the steep part so this might be worth another go, but it has more traffic and stops, including one at the base of a small climb.

(3) 1 pass : 88.6 mpg (SOC = 5 at start, 4 at finish, 72% EV, 21 mph)

Loop 4 = 5.8 mi. with 330’ climb over 1.1 mile followed by a gentle descent and (mostly) flat return.

(4) 3 passes: 91.7 mpg , 95.3 mpg , 99.6 mpg (79% EV, 19 mph)

I suspected from Google maps that Loop 4 is a textbook example of geography-assisted Pulse and Glide. But it was also slower than I typically travel when doing P&G thanks to low limits and light traffic. Lessons learned, and a nice scenic drive to boot. 1 year, 15000 miles and still loving the C.