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2017 Mountain Mode - Some Observations

1372 Views 12 Replies 11 Participants Last post by  zeldar
2018 Volt LT 97,000 miles.

Just FYI:

I am on a cross country trip through the rockies, much of it off interstates. This is my first time mountain driving in a Volt though I am an experienced mountain driver. I started in Wisconsin. Here are a few things I observed.

I drove up a 6% incline at 70mph for 2.5 miles in Normal Mode and the battery indicated miles dropped from 37 to 16 miles in that distance. Those indicated battery miles ticked down remarkably quickly. I was wondering how hot the electric motors must have gotten drawing all that power.

I drove up another 6% incline of 3 miles in Hold Mode (16 battery miles left). Nearing the top the engine seemed like it was screaming at a very high rpm. The coolant temp was 217 degrees at the top. The car made it with no apparent reduction in performance, but I think I was at the edge of what that car is capable of. I understand physics pretty well and that engine had to be working pretty hard to lift all that weight at that speed. The battery charges nicely downhill. During the subsequent descent the battery mileage increased to 29 miles, but I don't know how far it was.

Those were the only 2 notable up slopes on this trip so far (Santa Fe to Phoenix), but the next mountain driving leg will be up towards Flagstaff then Moab UT. I will use Mountain Mode for the remainder of the trip in mountainess areas. I am be curious to see how well it works. I am also curious to see what the battery charge level (miles left indicated) will be on the "other side" if I start mountain mode with a near full battery of about 40 miles indicated. Will it return to 40 after each descent?

Downhill driving is a breeze in Low. I'm don't think I engaged the physical brakes at all. I'm pretty sure all of the downhill speed control was done via regen. But I don't know for sure.

Interesting trip. 9 days left of 15. After Moab, it's Rock Springs WY then Denver. Another learning experience.
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I was wondering how hot the electric motors must have gotten drawing all that power.
The motors are designed with cooling and designed to go up mountains. I expect that they would get hotter driving on a flat road through the desert.


Nearing the top the engine seemed like it was screaming at a very high rpm. The coolant temp was 217 degrees at the top. The car made it with no apparent reduction in performance, but I think I was at the edge of what that car is capable of.
Remember that the Volt doesn't work like a normal car and the engine/generator is not attached to the wheels. The generator is optimized for running at a high RPM - much higher than a regular ICE car. The high RPM doesn't have a direct correlation to how hard a regular ICE car would work in the same situation. Its specific to the Volt and why you get much better mileage going up the mountain than an ICE car - even when you aren't using your battery.


Will it return to 40 after each descent?
The estimate should go closer to normal as you come back down, but you could see it spike really high as the computer "sees" efficient running. I expect the Guess-O-Meter (GOM) will not give you a good estimate until you hit a level stretch of road and you run for a while like that.
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