[redpoint5]

Originally Posted by Snax

While the differences should be less, driving style can make a significant impact.

If we disagree, it's probably about the definition of "significant".

I'll arbitrarily pick 3% as my threshold for what constitutes a significant difference with driving technique alone, and confine the dataset to the middle 80% of the normal bell-curve distribution, tossing out those who drive like the gas and brake are on/off switches, and likewise those who only drive steady speed on the freeway, and therefore technique doesn't play a factor.

Acceleration at a modest pace has an unavoidable minimum hit, but accelerating more briskly reduces efficiency, heating the controller, pack, and motor more. I can't really speculate exactly how much

If you're thinking about it, might as well speculate.

But what a lot of drivers in general fail at, EV or otherwise, is predicting traffic, and that can have a huge impact on regeneration potential as well.

Even full self-driving fails to do this, ignoring the red light ahead and accelerating towards it despite sensing the red light.

It matters much less when you can get 80% of that back, though.

bad drivers still get bad efficiency and drag the numbers down.

What percent difference do you speculate driving habits (same cruising speed and HVAC use) alone account for?

Originally Posted by Piotrsko

@redpoint5: you have done the testing to see if random driving a modern EV is only 1% different than max efficiency? Seems hard to believe that data would be so similar. I also find it hard to believe you are able to measure that 1% accurately.

I have not, which is why I suggest the test, especially with a forum member so relatively nearby (I'll say hi to freebeard while I'm there).

Having difficulty measuring to 1% would only matter if that's how insignificant the difference is, which would reinforce my point.

Originally Posted by aerohead

...once leaving Yellowstone... he had gained mileage the whole way.

I've only twice brought the Prius plug-in from zero EV range, back to full using regen (only ~3 kWh), and that was one of the instances. Ended up wasting a good deal of energy downshifting since once the battery was full, it was no longer slowing the vehicle.

The GM engineer who designed the Chevy BOLT reported that regen was responsible for 40-miles of it's EPA COMB MPG rating.

My spidey senses tell me it would be a very extreme scenario where 40 of the 250 mile range is provided by regen. Now that I've made that assertion, I'll see if math tends to support it...

According to Fueleconomy.gov, the Bolt uses 28 kWh per 100 miles.

40 regen miles / 100 miles = 0.4
0.4 * 28 kWh = 11.2 kWh gained from regen

The way to think about that is to imagine 11.2 kW (15 horsepower) being regenerated for 1 full hour. Of course, slowing isn't just a one time event, but spread out over the full trip length, and capable of up to 70 kW (94 horsepower).

In a hypothetical scenario where one could achieve full regen for 1 continuous regen event that supplied the full 11.2 kWh of charge back to the battery, it would take nearly 10 minutes.

It seems unreasonable to me that the Bolt could, on average, gain 40 miles of range by regen. My guess would be closer to 4 miles of range, on average. Some trips would be zero, like steady freeway cruising, and others would be more than 4, like stop and go traffic.