Regeneration milage on hilly vs flat roads?

[Delusional]

A somewhat specific question, but has anybody ever looked at this? City regen milage in hilly vs flat terrain?

Always been fascinated that, because of regeneration, electric vehicles get better "fuel" economy in city driving than highway cruising, which is the opposite of an ICE vehicle. As I rarely hit the highway in my work truck, i was glad that someday I would reap this harvest.
Lately I've been thinking that where I live is also quite hilly. I'm not climbing mountains, but I am rarely on a flat, level, stretch of road. Always going up or down hills.
Will the Wh/mile penalty for climbing the hills far exceed the regen on the way down, meaning I get less milage than a driver who lives in a flat area? Or I get better milage than in Kansas because they get less regen?

I suppose this relates to the efficiency of regen. Does downhill regeneration recover 80% of the uphill watts, or 50% or what? I know it cannot be 100%, which to me means the Kansas driver has an advantage.

 

[SSonnentag]

My initial guess would be 40%.

We frequent an 8-mile long steep hill. It takes 5% to ascend and we regen 2% on the way down.

 

[Delusional]

What grade does the hill have to be before regeneration reaches it's maximum? I'd bet that on a 1% downhill slope you are still using some accelerator pedal just to keep up with rolling and wind resistance. Does it have to be 2% downhill before regeneration kicks in at all? 4%?
I'd imagine at least half of my daily drive is an up or down grade of around 3% with some sections near 10%. Hmm, my F150 has the off-road slope indicator on the dash. Now I have a mission to check that data.

 

[Woodrick]

A somewhat specific question, but has anybody ever looked at this? City regen milage in hilly vs flat terrain?

Always been fascinated that, because of regeneration, electric vehicles get better "fuel" economy in city driving than highway cruising, which is the opposite of an ICE vehicle. As I rarely hit the highway in my work truck, i was glad that someday I would reap this harvest.
Lately I've been thinking that where I live is also quite hilly. I'm not climbing mountains, but I am rarely on a flat, level, stretch of road. Always going up or down hills.
Will the Wh/mile penalty for climbing the hills far exceed the regen on the way down, meaning I get less milage than a driver who lives in a flat area? Or I get better milage than in Kansas because they get less regen?

I suppose this relates to the efficiency of regen. Does downhill regeneration recover 80% of the uphill watts, or 50% or what? I know it cannot be 100%, which to me means the Kansas driver has an advantage.

Regen, on average is about 30%. The vast majority of that doesn't come from inclines, it comes from slowing down for traffic lights.

While regen may be a good part of city driving, it's not the real reason why ICE loses. ICE loses because they keep running at traffic lights. That's why so many are implementing start/stop.

Going over hills you can basically assume that regen will wash out the losses by going uphill. Sure, it's not 100%, but close enough. The average power utilization of a hilly section of road is pretty the same as if it were flat.

I've got a little hill that I go over down here called the Smoky Mountains. On the way up, I have a 15+ minute period where I am using over 999 wh/mi (that's as high as the meter goes). I can see my range drop quickly.

But om the way down, for 15+ minutes, the meter changes to -999. Which means that I'm putting over 999 wh/mi back into the battery and range starts climbing.

After it's over, the range is basically what it would have been if it was a flat road.