EV Range limit is only 86 miles?

The start of day, full charge ev range estimate is created by multiplying a computer calculated estimate of the vehicle’s average ev mileage (based on historical driving data collected by the computer, weighted for more recent data) by the amount of usable available power.

Keep in mind that no matter how far your drove the previous day, the full charge ev range estimate for the Gen 2 will be determined by multiplying a usable power amount of ~14.1 kWh by an ev mileage number. The question is, how does the computer algorithm calculate that mileage number? Is there a fixed limit to the displayed range estimate (as 50 miles was for the 2011/2012 Volts and 60 miles for the 2013/2015 Volts), or is your displayed 86 mile estimated range accurately reflecting recent achieved "ev mileage?"

The kWh Used number shown on the energy usage display screen is a net calculation (grid power used less regen put back into the battery). Nissan Leaf owners once had a "Carwings" app (perhaps they still do), detailing the power consumed for each trip as a sum of the battery kWh Used (positive) and the regeneration obtained during the trip (negative). It could be the Volt computer maintains the same grid power/regen power consumption data, and uses total trip power consumption data, not just grid power data, when creating the "average ev mileage" number used to calculate the full charge range estimate. How much regen power was included in the total power you used to drive those 90+ ev mile trips?

Your route apparently included a lot of downhill driving. Driving a route that allows you to add a significant amount of downhill regen to your "Electric Mode" fuel supply might allow you to drive more Electric Miles, but if the "level terrain ev mileage" you get from use of grid power is about the same as the "level terrain ev mileage" you get from use of regen created power, the start of day, full charge 86 mile ev range estimate might well be a calculated number, not a maximum number. The full charge range estimate isn't going to estimate how much regen and regen miles you might get that day.

Your ~500 ev miles in a day post mentioned that you added some Electric Miles at the end of the drive by using Mountain Mode to recharge. It could also be that any "Electric" miles driven on MM recharged battery power are excluded from the start of day algorithm’s average ev mileage calculations. My 2012 Volt has the quirk that allows MM power to be counted as Electric Miles, but the kWh Used number on the display does not change as the power is used. This quirk once produced a display screen showing I had driven 89 Electric Miles on 9.8 kWh Used. The following day’s full charge ev range estimate did not receive a "bump" from this "I averaged 9+ miles/kWh over ~90 miles" achievement. By not increasing the kWh Used number when MM-recharged power is used, the computer is identifying it as "not grid power," so perhaps the computer also does not include any "Electric" miles driven using the MM-recharged power when calculating the average ev mileage to apply to the full charge ev range estimate calculation.

Perhaps these observations will add to the discussion of how the ev range might be calculated.

I note that neither of the two charts you posted indicate a full charge electric range for a 2017 Volt of more than 70+ miles, suggesting the 90+ mile numbers you are getting are much rarer. Our friend Ari C drove 114.0 electric miles on 14.4 kWh of power using his wife’s Gen 2 Volt (no gas used, no gas miles), so it is indeed possible to reach those distances on a full battery charge. If I recall correctly, his next day full charge estimate was 84 miles.

Your description of the route you used for your ~500 mile in a day drive seemed limited to level terrain, downhill, level terrain, downhill, ending with a little Mountain Mode recharging. The finer details of the achievement, such as average speed and how the other drivers on those roads were reacting to such slow driving (and where those roads are, for others who might like to attempt to reproduce your results), were not given. The implication is also that your long electric drives are achieved because they include several downhill sections (for regen), and are not round trip events. Ari’s 114.0 mile drive was mostly driving in a big oval on relatively level terrain. It doesn’t seem unreasonable to expect someone who posts pictures of a usage screen showing 186.8 and 199.7 electric miles driven using only 14.2 and 14.1 kWh with no gas used to elaborate on how this was achieved.

les.miller said:

I do not understand. Even your graphs show that it is impossible. I’m thoroughly confused unless you were driving 20 mph downhill for 25-30 miles.

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If you have followed my other posts about these graphs it was explained in their proper context. My point was I've been collecting data, very observant with my Volt and I am insulted if someone calls out my observations as BS when I provided proof against their disbelief.

These graphs were for normal driving, such as level roads, more or less maintain constant speed, and then analyzed statistically for the patterns when using your Volt normally.

I was pushing limits of the Volt, beyond the confines of these graphs. In fact Ari Collins was able to do 122 miles on a charge driving less than 25 mph along an elliptical stadium for hours. I pushed it further on my first try by finding elevated charging stations and slide down from there and I have achieved 186 miles to a charge.

I then took up the challenge of beating the record in VoltStats for number of electrical miles driven in a day, and I have studied those graphs to aid me in the optimal speeds to use. I then have a fully charged Volt starting out at the highest elevation that I can find, and then driving level road at optimal speed to deplete the battery then slide downhill until battery is near fully charged and then drive level road again to deplete it and continue the process. I achieved nearly 200 miles to a charge. This is a record achievement run, not your normal use of the Volt, the same reason why Tesla drivers would crawl drive to establish the longest distance records with Tesla, or why would someone climb the peaks of the mountains...

So I used various hypermiling techniques. I've even calculated the expected recharge rates for regen from downhill elevation changes. Did some tricks with mountain mode and normal mode... In many of these instances between recharges, I achieved at least 90 miles to a full charge, going as high as 199 miles. That's when I noticed why the GOM for the EV Range seemed to max out at 86 miles. Normally, the EV Range in the GOM reflects your performance the previous charging cycles, and all my previous charging cycles were over 90 miles to a charge and yet, the display for the start of the next run never exceeded 86 miles for me, and that is why this post. So I'd be the first one to actually confirm this limit on the display if no one else can show me.

JoeReal said:

My record of 199 miles for a single charge has no external charging, as I have used 14.1 kWH shown in the DIC. But it was from the highest elevation that I can find, drove like a grandma in the windflow level road, then when battery was depleted, drove downhill at optimal speed for regen, and when the battery nears full from the regen drive level road again and repeat the process. The overall conversion efficiency of potential energy from elevation change to regen is approximately 75% and by driving carefully I didn't lose anything to friction braking. My record can be beaten if a higher elevation can be found to start driving.

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The 75% recapture from regen seems to agree with GM statements in the past.

Going 199 miles on a single charge can be misleading without knowing it's really 199 miles with lots of coasting/regen down a mountain road. A bit like loading the fully charged car into a rocket, shooting it around the moon, bringing it back to earth, and claiming the car traveled thousands of miles on a single battery charge. It did technically, and it didn't in the way most people would travel on a charge.

In both cases, the energy it took to get to those heights and make the claims is not accounted for. The regen/recapture traveling downhill is recovering what? The energy it took to go UP the mountain. No free lunch.

Same with orbiting the moon. It took a lot of energy to boost the car into orbit. So both claims, to be accurate, should account for the energy used to go uphill in order to go downhill. I suspect a net energy loss in both scenarios. The 75% regen recapture suggests that at least 25% of the energy it took to go up the hill was lost going down.

If gas was used to go up the hill, it's even worse. Gas engines are only 25% efficient at best, wasting 75% as heat and noise. But maybe I am all wrong. How did you get up the hill to do your downhill, record setting "199 miles on a single charge"?

Markjn said:

I have only had my 2012 Volt since November and have only ever seen 33 miles estimated range and only 40 degrees F except for today which was 60F but my charger (outlet apparently) failed last night and I only had 9 miles EV range this morning.

My commute has required the gas engine to kick in every single day since the day I got it.

I had my charge cable fail 1 week after getting my car and I spent a week on engine only until I got a new cable.

I spent over two weeks at frigid temperatures that required ERDTT most of my drive every day. And one day it gave me dismal 19.1 mpg.

But my lifetime mileage is still better than the OP. Lots of (inefficient) effort going into getting some big numbers on the display.

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The OP prefers to configure his display screen for "MPGe" numbers, which aren’t available on the 2012 Volt’s display screens (I’ve been driving my 2012 Volt for 5.5+ years now). His MPG and MPGcs lifetime numbers are much higher (1000+ for MPG, ~47 MPGcs).

One "gallon," in miles-per-gallon-equivalent terms, is equivalent to the energy available in 33.7 kWh of electricity taken from the wall. The battery of the Gen 2 Volt holds about a "half-gallon" of MPGe fuel per full charge. Averaging 114 MPGe in a car rated at 106 MPGe is somewhat like averaging 26.8 MPG in a car rated at 25 MPG.

For some reason, much of the discussion of an electric car’s performance is carried out using language associated with gas propelled vehicles (i.e., MPG, MPGcs, MPGe). Seems to me the small distance once can drive on the electric car’s "unit of fuel," the kWh, muddies the discussion. The Electric Mode range difference between the Gen 1 and the Gen 2 Volt, or the Volt and the Bolt, is credited to a difference in fuel tank capacity (i.e., the usable battery size), with little recognition of differences in ev fuel efficiency or other engineering.