[WopOnTour]

I've had my Volt since April. I am in San Francisco, so the temperature variance is not great. Prior to the software update, I had been getting a consistent 37-42 miles per charge mostly with typical rush hour freeway driving. Since the update, my estimated range went dramatically down (32). I read the forums and the comments about the reset and running it through a few charges and all would be good. Unfortunately, my actual range is way down - to around 30 miles. The last 5 times I ran from full charge to gas, the miles were: 30.8, 31.2, 21.8 (that is not a typo, 21.8), 30.2 and 30.5. Nov-Dec temperatures here are still in the 50's. Is actual (not estimated) range likely to change by running through another 5-10 charge cycles? I have used more gas in the last month than in the previous 6!

Again, NORMAL!
Merely an issue of bad timing.
The cooler weather in CA (and elsewhere) is masking the benefits of the software upgrade.
Just keep driving it (as efficiently as you can) and as conditions improve so will your EV range.
WOT

 

[Chevrolet Customer Svc]

@ nblumenfield,

WopOnTour is correct. When you got your Volt in April the temperatures were starting to warm up. Now that the temperatures are dropping a little, your range will as well. As mentioned, just keep driving it as efficiently as you can and once things start warming up in the spring, you're range will be back to where it was.

 

[fishhawk]

Like others here, I have experienced a reduction in range since I got the update AND the weather got colder. However, today it was 70 degrees here, and I drove 35 miles EV, and when I got home, I still had 9 miles estimated renaming. In other words since the weather is much warmer today, the range has returned to normal.

It's like WOT says, it's the drop in temperature that as reduced the range. I fully expect to be back in the low 40's next summer, just like this past summer.

 

[spreston]

What's really happening when someone's mileage drops really low such as 21.8 versus a normal 30 miles? It doesn't seem like it's the normal temperature, terrain, technique. It seems like the computer just decides it's only going to go that far on a charge even though it doesn't sound right that the battery would all of a sudden have 30% less charge.

Does the Volt's software really go off the measured amount of juice in the battery, or does it make a calculation on when it thinks the battery is low enough and switch to gasoline?

 

[Steverino]

It seems like the computer just decides it's only going to go that far on a charge even though it doesn't sound right that the battery would all of a sudden have 30% less charge.

Does the Volt's software really go off the measured amount of juice in the battery, or does it make a calculation on when it thinks the battery is low enough and switch to gasoline?

How does your car decide when the gas tank is empty? Same thing. It's based on how much is remaining. But the Volt can determine "empty" for a battery with much more precision than gas remaining in a gas tank. It is not guessing or doing tricks.

 

[tboult]

What's really happening when someone's mileage drops really low such as 21.8 versus a normal 30 miles? It doesn't seem like it's the normal temperature, terrain, technique. It seems like the computer just decides it's only going to go that far on a charge even though it doesn't sound right that the battery would all of a sudden have 30% less charge.

Does the Volt's software really go off the measured amount of juice in the battery, or does it make a calculation on when it thinks the battery is low enough and switch to gasoline?

The switch is based on actual battery state. The predictions are, well, predictions. They are based on recent driving. If I do a much of driving around my local town, then charge up it may say I can do 42 miles tomarrow. If I drive to work then back home, the 800' of elevation makes it say 38 the next morning. What I did monday has a smaller impact but still some. And if its 28 today it might be 36 miles, if its 40 it might be 40. For many people the EER drops quickly when they start driving as it goes from the 40degrees of the garage to the actual temp outside, say 28, so I can go from 40mile EER to 36 in a under a mile. (And have the "engine running due to Temp if its cold enough).

I have had a day where I saw much much lower actual range, when my wife had borrow the car for errands, turned the heater to comfort/75, and not returned it to my setting. The next day my battery range drop much much faster. On the way in I was in a hurry, so not paying attention, driving 85 and being agressive at lights/stops. When i was driving home I realized I was hot, and return the climate to my setting (none). But that day my actual ranged dropped do 30miles, or about 8-9 miles below my usual daily drive. Next day my estimate was 34.


Also if you leave the car "on", (done that too while running late), it will really eat up some battery sitting there.

 

[Positron]

Does the colder weather have an effect on regen?
I too have noticed a (seemingly) reduction in regen potential. Coincidentally after a trip to the dealer and some cooler nights. Was 47 this morning. Before the car was very aggressive in L, which I like. The last two trips I've found myself approaching the car ahead much more quickly, applying more brake pedal and the green ball going down much further than normal. Before seems like you could just barely apply the brake into the regen and the car would really slow down.

I hope it's just the cold as I really like this decel. I've run the same route every day for the last 49 weeks and it had to be this cool last Jan and I don't remember it doing this last year (or the lower mileage, but that's been beat to death.) I even adjusted the seat thinking the lot guy moved the seat back or something.

 

[Chevrolet Customer Svc]

@ Positron,

I went ahead and checked and it looks like colder weather has no effect on regenerative braking.

 

[Positron]

Trevor, thanks for researching and getting back.

My tin foil hat guess is that they turned it down to get you more into the brakes to appease the whiners that complained about the lights not coming on under hefty regen.
I'd like to whine and get it back.
//foil hat off
Otherwise I'd take it in to have it looked at but having another person drive this car without history would not be able to duplicate customer concern and I'd be dismissed.

It doesn't stop as aggressively as before, but all I have is the seat of my pants to articulate with.

 

[socaldriver]

Do not get the software update it ruined my EV mileage and The Volt advisory team is not willing to take any responsibility in solving the problem. I live in Southern California the weather is never that cold. Prior to the update I was consistantly charging my car to 40miles and getting 38-42 EV miles every day. Since taking the update the best my car has charged to is 32 mile which is also the best EV miles I have recieved. When I talk to the Advisory team they blame my use of the radio, the heat the air the way I charge the car, anything but the update itself. The only thing that has changed in the way I drive this car from before the update to after the update is my greater consumption of gas! For the record the weather was already cold prior to my getting the update so the whether is not the problem. This is the first American car I have owned as an adult and I am greatly disappointed with the response I have reieved from Chevy so it will probably be my last American car as well. I am really saddend by the entire situation because I loved the car right up until the day I had the update done

 

[ChasSidwa]

Do not get the software update it ruined my EV mileage and The Volt advisory team is not willing to take any responsibility in solving the problem. I live in Southern California the weather is never that cold. Prior to the update I was consistantly charging my car to 40miles and getting 38-42 EV miles every day. Since taking the update the best my car has charged to is 32 mile which is also the best EV miles I have recieved. When I talk to the Advisory team they blame my use of the radio, the heat the air the way I charge the car, anything but the update itself. The only thing that has changed in the way I drive this car from before the update to after the update is my greater consumption of gas! For the record the weather was already cold prior to my getting the update so the whether is not the problem. This is the first American car I have owned as an adult and I am greatly disappointed with the response I have reieved from Chevy so it will probably be my last American car as well. I am really saddend by the entire situation because I loved the car right up until the day I had the update done

So how long ago did you get the update? I had mine about 10 days ago and am back to all my pre EV range. It does seem to have to relearn.

 

[socaldriver]

Update was done about a month ago. My car did not seem to relearn and is not even getting the 34 miles it was supposed to reset to.

 

[kmg]

My car went from an average range of 43 miles per charge down to 37 miles immediately after the upgrade, but the temps did drop the week I did it. I am averaging 39 to 40 now, in fairly cold temps for SoCal, after 10 or more charge cycles. The true test will be what I get next summer. Will it return to the consistent 43s I got last summer with the original software, or not? Only time will tell.

By the way, I suspect the NIGHT TIME temperatures factor heavily into the mileage prediction, since that is normally the temperature the battery system is at during recharging, and is close to the temp the car is at in the morning. In SoCal, even though it has been in the mid 60s during the day, the temps have been around 39-40 almost every night for the last month.

 

[socaldriver]

That is the argument I get from the Volt advisory team and while that might be true, in my case we were already into the cold temps when I took the upgrade and in the cold temps I was getting my 40 miles. My disappointment is not only with the car but the total lack of any kind of customer care on the part of the Volt team. They were happy to speak with me when my answer was I love this car but as soon as the answer was I am unhappy I got one ridiculous answer after another always blaming the weather or how I was driving the car, it would be nice if perhaps the answer would be "maybe there is a problem with your car and we will have a tech come look at it. That possibility is not within the sphere of the volt team logic.

 

[WopOnTour]

Do not get the software update it ruined my EV mileage and The Volt advisory team is not willing to take any responsibility in solving the problem. I live in Southern California the weather is never that cold. Prior to the update I was consistantly charging my car to 40miles and getting 38-42 EV miles every day. Since taking the update the best my car has charged to is 32 mile which is also the best EV miles I have recieved. When I talk to the Advisory team they blame my use of the radio, the heat the air the way I charge the car, anything but the update itself. The only thing that has changed in the way I drive this car from before the update to after the update is my greater consumption of gas! For the record the weather was already cold prior to my getting the update so the whether is not the problem. This is the first American car I have owned as an adult and I am greatly disappointed with the response I have reieved from Chevy so it will probably be my last American car as well. I am really saddend by the entire situation because I loved the car right up until the day I had the update done

Everybody in California is experiencing the same thing.
It is related ONLY to the cooler weather in the past few weeks.
It really has NOTHING to do with the "update" itself more to the after effect of resetting of various statistical base-lines.
Eventually it will learn it's way back.
WopOnTour

 

[socaldriver]

I am sorry but that just is not true. I have two friends who have the 2011 Volt, they are the people who convinced me to get the car. Neither one of them took the upgrade and neither one of them have suffered any mileage Deterioration. It is predicted to be in the 70's next week we will see if the warmer weather really does fix my problem. If so I owe everyone an apology but I am not holding my breath.

 

[WopOnTour]

I am sorry but that just is not true. I have two friends who have the 2011 Volt, they are the people who convinced me to get the car. Neither one of them took the upgrade and neither one of them have suffered any mileage Deterioration. It is predicted to be in the 70's next week we will see if the warmer weather really does fix my problem. If so I owe everyone an apology but I am not holding my breath.

But it is true. So sorry if you dont believe it.
The primary difference being your friends cars have yet to have their statistical base-lines "reset" by the update process. (something established over the course a number of days and weeks) Right now YOUR statistics are exclusively based on nothing but cooler ambients being present, that is the difference. In the long run it is you that will be getting more efficient EV performace and better CS mpg than they (should they not receive the update) So this is merely just a matter of bad timing.

The anticipated improvement in ambient temperature in California will need to be present for ~8-10 drive-charge cycles in order for it to be statistically valid for the range estimation algorithms to self-adust. But if it's 70F for say 7-10 days or so and you drive it daily as efficiently as possible, your previously observed range (or better) WILL return once again.

Welcome to gm-volt.com
WopOnTour

 

[kmg]

Yes, it is supposed to get a little warmer (70s) next week in SoCal, in the daytime. What about at night? By the way, last night at midnight it was 34 degrees in my SoCal garage, while the car was merrily getting it's recharge. The cold air almost took my breath away when I checked on the car as I was locking up.

My car is usually parked in the sun at times during the day, and it can get quite warm inside from that, which I think helps a little with the range estimates and performance.

Only other suggestion I can make is to be sure your car isn't showing any error codes following the upgrade. I had OnStar do a diagnostics run by my request, and that, plus the regular report I get monthly, show my car is error free.

 

[socaldriver]

But it is true. So sorry if you dont believe it.
The primary difference being your friends cars have yet to have their statistical base-lines "reset" by the update process. (something established over the course a number of days and weeks) Right now YOUR statistics are exclusively based on nothing but cooler ambients being present, that is the difference. In the long run it is you that will be getting more efficient EV performace and better CS mpg than they (should they not receive the update) So this is merely just a matter of bad timing.

The anticipated improvement in ambient temperature in California will need to be present for ~8-10 drive-charge cycles in order for it to be statistically valid for the range estimation algorithms to self-adust. But if it's 70F for say 7-10 days or so and you drive it daily as efficiently as possible, your previously observed range (or better) WILL return once again.

Welcome to gm-volt.com
WopOnTour

There are so many problems with your response I wouldn't even know where to begin. Let me leave it at this, if for the sake of argument I agree with what you say that the cold weather is the cause of the problem, then it causes me even more concern with logic skills of the Volt technology team. Why would they release a software upgrade for the car that is supposed to improve mileage but only after consecutive charges in warm weather and choose to realease such an update in the winter? It is either really poor planning or not understanding the impact of the update until after the fact. Either way it was a bad decision on the part of the Volt Team.

 

[Al Micucci]

I'm with you as far as the lousy numbers for charging the vehicle and the lack of response by Chevrolet. Since the "upgrade" I can only get about 29-30 miles on a charge. At approximately 12kwh to charge, it's hardly worth it. I was also extremely please with the car until i had the upgrade done. Too bad they won't take responsibility. It almost makes me want to use the fire excuse to get a different car.