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Discussion Starter #1
Hi,

I purchased a Bolt several weeks ago and absolutely love the car. It is amazing. For the most part, I've gotten the 238+-/charge range expected. I have always (until yesterday) charged from my Level 2 charger at home. Yesterday however, I took a trip to Philadelpha, a one way trip of 126 miles. I arrived with a medium expected range of 130 left on the car. That should have gotten me back if I had tried to make the trip on that single full charge. I added 60 miles however by charging at the local Chevy dealer's L2 charger. With the 60 mile cushion, I would have expected there to be no range anxiety on the return trip but that was not the case. By the time we were halfway home, we were looking at a margin of error of only 4 miles. This was unnerving to say the least. By the time we got home, we were up to a 28 mile cushion of charge. Since the trip was the exact same trip and we actually drove a little slower on the way back, I cannot understand the difference in milage.

For all of you Sherlocks out there, here are the clues to consider:

We drove at 68 mph on the way down (cruise control).
We drove for the first half of the way back at 71 mph (cruise control). For the second half of the trip, we drove at 45-55 mph (not using cruise control).

Traffic flowed equally on both legs of the journey. No stoppages.

Is this important?: At one point, during the first half of our trip back, the car shifted (of its own accord) to the L mode. I did not hit the gear shift to my knowledge but had just braked slightly with the steering wheel paddle. I think that this might have been consistent with the loss of range but am not sure. I thought that L mode was used to add regenerative power but it feels like I'm driving in low gear in an ICE when I use it. Could this have been the cause of the range loss?

We had air conditioning on (71 degrees in the car, 80 degrees outside) and were using the radio.

Any ideas as to why we'd have that range degradation? This makes me a bit nervous to take long trips until I understand the factors in range variation in the car.

That said, the Bolt is an amazing car. I've bonded with it.

Thanks for your thoughts in this.
 

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Well first, the speed difference from 68 to 71 is a decent power increase. The amount of power required the faster you go is exponential. This is an example based on a few other cars, not sure what the power curve would be for the Bolt. power curve

Once you go past 55 mph the power required to maintain velocity increases significantly per mile.

Second thought. What are the elevation profiles of the trip? Is it more uphill going back home compared to going to Philly? Going uphill of course is another big power drain, especially if you are going faster uphill than you were coming down.
 

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Discussion Starter #3
I wondered about the elevation change. There is a 460 foot difference. We were going downhill on the way to Philly and gently uphill on the way back.
 

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I wondered about the elevation change. There is a 460 foot difference. We were going downhill on the way to Philly and gently uphill on the way back.
Yeah, going uphill makes a big difference. I make a trip to Shenandoah National Park often. On the way there (uphill) I even driving conservatively can only get in the 3.5 kWh range, a lot lower if I drive fast. If I do 60-65 there the whole way with AC it is normally around 3.1 kWh. On the way back though since it is more down than up, I can easily get 4.4kWh - 4.8kWh pretty easily.
 

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Wind can also make a big difference. Even a 5 mph wind could make the 68 mph portion an effective 63, and the 71 mph return an effective 76 mph.
Never realized how important that was and how much it impacts how we drive but one thing I learned because of this is that you should keep your car very clean at all times. Any way to cut down on wind resistance will be a gain.
 

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I was returning from Lexington, VA (1000' MSL) over a 2500' range to my 500' MSL destination 226 miles away. Fortunately, I had made the "climb" direction trip (@ 60 mph CC) one week prior and had arrived with 20+ miles range "in the tank". At the peak elevation, I had 110 miles to go with a 90 mile expected range showing. Over the last 100 miles I observed the expected range rise to a 40 mile reserve. Elevation really does count! I wish PlugShare posted elevations for planning purposes. GoogleEarth can give useful qualitative data, but quantitative elevation/range data is not really possible and one must always a "plan B".
 

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Before Brammo closed down their motorcycle business, I know they were thinking about releasing a trip-planning app that would take into account not only speed, but elevation changes for their GOM readouts. Seems like a good opportunity for some coders.
 
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