Long highway hill tactics

[Uriel]

I have a hill on my homeward commute that requires some care to avoid IMA regen yoyo effect. It's rises 123m over 5.3km (according to Google Earth) on a 70mph (excuse the mixed units, I'm British ) limit dual carriageway, with the steepest part about 10%. That's part of a 13.7km trip. At the bottom of the hill there's a roundabout - so you're accelerating from a dead stop.

General observations so far:

• Driving the speed limit (70mph):
  I get best results from either driving in S at high rpm all the way up using 5th and 6th gears at 70 on the hill. Similar results can be had by using low rpm and maximising assist by holding 7th as long as possible then 6th to maintain speed when assist runs out. Either approach prevents uphill regen and results in around 43-45 mpg (UK) for the trip. Holding 70mph in D (normal or econ) results in heavy assist, followed by regen and usually less than 40mpg.
• Driving with Load
  I don't have a scangauge or anything but I gradually speed up to around 65 to 70mph before hitting the steepest part of the hill. I then allow speed to drop until the speedometer goes turquoise and hold the foot steady, allowing speed to bleed down to about 45-50mph over the 2.5km steepest part of the hill then hold speed steady for another 1km to the top. The best I've seen for the home trip using this approach is about 51-52mpg.

Personal best going in the opposite direction is 60mpg. There is no way to avoid the hill, although it can be tackled on slower roads (with similar elevation changes).

Any thoughts on the above approaches or think there may be a way to do it better?

[Moviemike]

Originally Posted by Uriel

......Similar results can be had by using low rpm and maximising assist by holding 7th as long as possible then 6th to maintain speed when assist runs out. .....I gradually speed up to around 65 to 70mph before hitting the steepest part of the hill. I then allow speed to drop until the speedometer goes turquoise and hold the foot steady, allowing speed to bleed down to about 45-50mph....

......Any thoughts on the above approaches or think there may be a way to do it better?

After much experimentation I've come to pretty much the same technique as you've described above. Only thing I may do differently is shift into S, 52 mph seems like a good shift point, while holding the throttle steady.

To do better may be a challenge!
If possible increase the effeciency of your acceleration process. From a standing start, I accelerate at the "slow normal" rate of surrounding traffic. As I pass through 30 mph I ease up on the throttle, and seek to maintain a slower rate of acceleration equal to about 50 mpg on the MID"s instant mpg slider gauge.

Lower speeds, especially during the final up grade. Maximum use of flat or flat-er portions of the climb to increase vehicle speed.

Higher tire pressures to reduce roll resistence.

Maximum battery charge at bottom of hill. ....a photo voltaic collector in the roof and a sunny day to keep the battery charged as you climb...