[Ziv]

I have had my 2013 Volt for 5 years and have seen pretty steady range results with the usual seasonal oscillations. Generally my warm weather, real world AER is between 38 and 44 miles (GoM usually a mile or two more) depending on weather, amount of passengers, AC use and type of driving. But over 4 summers, it has been pretty steady. Up until April, everything looked the same, I started to get my warm weather increase on both the GoM and in real world range. Then in late April/early May I noticed that my range had dropped off and was 31-36 miles, not 38-44. My morning drive to work is short but it went from 0.7-0.8 to 0.8-0.9. Almost too short to be useful, but consistent with my other range loss numbers. The amount of gear I carry has stayed the same, my driving pattern is the same, my AC use is the same. I recently got the oil changed, which shouldn't matter but it didn't change anything with regards to range, so no surprise there. 2 of my tires are nearing end of life with 6/32 of tread left, but they were balanced and rotated just 8,000 miles ago when I got 2 new tires.
I have tried braking hard to re-set the brakes in case a caliper was dragging, but I don't have a lift to check and see if the tires are rotating without dragging.
Any suggestions on what I should check before I take it to the service department for my 5 year coolant replacement? I will probably replace the 2 older tires at that time, but new tires usually drop range, not increase it, at least for the first thousand miles or so.
I doubt that battery age would manifest itself over a time frame as short as 2 months, but I can't figure out what I am missing. Any suggestions would be greatly appreciated!

 

[Synovialbasher]

You probably already checked it, but tire pressure makes a difference! Whenever I take mine to discount tire to get balanced they lower them to 38 PSI. I like to keep mine at about 41-42, so I have to remember to add air afterwards. I notice a slight difference in range when I don't.

 

[Ziv]

Good point, synovialbasher. I used to do 41 but had 2 flats and reduced it to 39, no flats since I lowered the pressure. Post hoc ergo propter hoc, I know.
But you are right, there was a slight reduction in AER when I dropped the PSI. After dropping to 39 psi, I just haven't gotten the long range days where I get 48 or 50 miles as often, but this recent reduction in AER seems to be a bit more drastic than the small reduction in AER I saw when I went from 41 to 39.
Regardless, I think I will goose it back up to 41 for a week and see if it helps.

You probably already checked it, but tire pressure makes a difference! Whenever I take mine to discount tire to get balanced they lower them to 38 PSI. I like to keep mine at about 41-42, so I have to remember to add air afterwards. I notice a slight difference in range when I don't.

 

[fotomoto1]

For brake drag, you can check the wheel for heat and compare to the others; also if there's more brake dust but that usually takes much longer to observe unless the drag is REALLY bad.

Did you change to different tires; especially non-LRR types? If so, you should have seen a difference 8,000 miles ago.

 

[emartin00]

Hard braking isn't going to "reset the brakes" it's going to make them stick more.
If you think they might be dragging, see how warm they are after a drive. I had a rear brake that was dragging, and i burnt my finger touching the rotor after a 6 mile drive. (use an IR thermometer rather than your fingers...)

 

[Ziv]

I have been thinking that I need an IR thermometer for real estate/HVAC purposes for years. Now I have another reason. Time to get one. Holy c***! I thought they would cost $50 or so. $16 for a decent one on Amazon.

 

[JuneBug]

I have been thinking that I need an IR thermometer for real estate/HVAC purposes for years. Now I have another reason. Time to get one. Holy c***! I thought they would cost $50 or so. $16 for a decent one on Amazon.

I got one from Harbor Freight a couple of years ago for that price with a coupon. Works very well, the only bad thing is it defaults to C and you have to push the button for F every time you turn it on.

 

[2VoltFamily]

Was it an actual range loss or just a reduction on the guess-o-meter? With such short drives the computer for the GOM probably needs a few full discharges and recharges to get reset.

 

[2VoltFamily]

also, is your 2013 on the recall list?

 

[Ziv]

Was it an actual range loss or just a reduction on the guess-o-meter? With such short drives the computer for the GOM probably needs a few full discharges and recharges to get reset.

It is real range loss. My GoM has always been a bit optimistic, so I measure my real world AER fairly frequently. Early this spring I got all my usual spring "return of AER", but several weeks after the range came back, it suddenly went away again, despite the temps continuing to rise and despite me using less AC than usual and driving like even gentler than usual trying to get it back. I usually use Eco 2 or Eco 3 and lately I have been using fan when possible and Eco 2 is as high as I go most days. I don't think my 2013 has any recalls. I just had it serviced at a GM dealer and they didn't pick up on one. Doesn't mean there isn't one, but I haven't seen any.

 

[1branchonthevine]

I put 100% of blam on the tires. I changed tires on my hybrid years ago and lost 10mpg. I only use OEM factory tires anymore. If you want to keep the higher mileage, go to dealer, make sure they dont swap with less expensive brand. If you cant get the OEM tires anymore, I usually buy the tires online. Look for high PSI tires, sorry to counter your lower PSI intentions, but I always over-charge my tire pressure by at least 4psi intentionally to maintain high mileage. I haven't done the math, but I figure I save the difference in buying OEM over the life of the tire in gained efficiency. By the way, some forums mention spongier lower PSI will get you more nails stuck in the tire, so beware.

 

[Ziv]

I hear you, vine, and I think that my tires may have something to do with it, but the part that stumps me is why did I get my warm weather AER back, and then lose it in just a week or two? I was going to wait until just before it snows to replace my older pair of tires, but now I may replace them sooner to see if it makes a difference. I should be getting my IR thermometer this afternoon, so I will be able to check to see if one of the brakes are dragging, too. My pack still shows 10.3 kWh used when it shifts to the genset so it doesn't seem to be pack degradation, but you never know exactly how an aging pack will manifest range loss. But I think it will show in the amount of kWh used.

I put 100% of blam on the tires. I changed tires on my hybrid years ago and lost 10mpg. I only use OEM factory tires anymore. If you want to keep the higher mileage, go to dealer, make sure they dont swap with less expensive brand. If you cant get the OEM tires anymore, I usually buy the tires online. Look for high PSI tires, sorry to counter your lower PSI intentions, but I always over-charge my tire pressure by at least 4psi intentionally to maintain high mileage. I haven't done the math, but I figure I save the difference in buying OEM over the life of the tire in gained efficiency. By the way, some forums mention spongier lower PSI will get you more nails stuck in the tire, so beware.

 

[jbakerjonathan]

I put 100% of blam on the tires. I changed tires on my hybrid years ago and lost 10mpg. I only use OEM factory tires anymore. If you want to keep the higher mileage, go to dealer, make sure they dont swap with less expensive brand. If you cant get the OEM tires anymore, I usually buy the tires online. Look for high PSI tires, sorry to counter your lower PSI intentions, but I always over-charge my tire pressure by at least 4psi intentionally to maintain high mileage. I haven't done the math, but I figure I save the difference in buying OEM over the life of the tire in gained efficiency. By the way, some forums mention spongier lower PSI will get you more nails stuck in the tire, so beware.

It's too early in the morning for me to search for the citation, but, I read a government report done in the '60s or '70s on tire performance relating to tire pressure. An eye opener for me was that (among other, positive, effects) INCREASED tire pressure resulted in decreased resistance to punctures (higher pressure - more puncture probability) due to the decreased flexibility of the rubber tread to yield.

To the OP, a reading of A Tale Of Two Volts might shed some light on your problem:

https://gm-volt.com/2013/02/26/a-tale-of-two-volts-the-summary/

 

[Ziv]

Interesting, Jonathan! I do not use the genset very frequently so I seldom get below 1.0 kWh left in the pack. I think I will take the time to fully exhaust the pack a couple times this week and see if that helps get my AER back where it should be. I have only used 43 gallons of gasoline in 61 months of ownership, so my pack is fully exhausted fairly infrequently.

It's too early in the morning for me to search for the citation, but, I read a government report done in the '60s or '70s on tire performance relating to tire pressure. An eye opener for me was that (among other, positive, effects) INCREASED tire pressure resulted in decreased resistance to punctures (higher pressure - more puncture probability) due to the decreased flexibility of the rubber tread to yield.

To the OP, a reading of A Tale Of Two Volts might shed some light on your problem:

https://gm-volt.com/2013/02/26/a-tale-of-two-volts-the-summary/

 

[Loboc]

Looks like all the suggestions I was thinking are already here. Might check alignment when you get the other two new tires. In general, I replace tires as a full set so there aren't ghost variations like this.

And yes, I had a few recalls (not safety recalls) with my 2013 Volt. The newest one is some sort of battery management software update. This model year also had the steering rack recall for some VINs. This had to do with an on-center 'bump' on long stretches of straight road. May or may not have anything to do with range.

I'm leaning toward the battery never being fully discharged, so, it can't balance the cells as well. It also may need to zero out so that it 'knows' the starting point.

 

[Ziv]

I fully depleted the battery last night doing an efficiency check at 44 mph on level surface with the AC on Eco 1. I started the run with 3.2 m/kWh and got it up to almost 3.9, which means the check part of the days driving got me around 4.5 m/kWh, since more than half my total miles were regular driving. Though better than the past month of regular driving, it is still way worse than my usual 4.8 to 5.4 for an efficiency check. I have only had an efficiency check below 5 m/kWh once.
I have the IR thermometer arriving later today for a brake check, I am going to edge the PSI up to 41, and I will fully exhaust the pack again today.
Thanks for all the tips!

 

[Ziv]

All 4 discs were 88 degrees after a 15 minute drive so it doesn't look like a dragging caliper. I have nearly fully exhausted the pack 2 nights in a row and I may be seeing a bit of a return of my missing range. I will keep using it up every day for a couple more days. I am thinking it may in fact be "A Tale of Two Volts" situation, where the pack loses capacity after not being fully exhausted very often over an extended period of time.

 

[VoltenRock]

Make sure auto-defog is off also. With warm weather, also check for battery cooling as the culprit. Even if plugged in, it's not always guaranteed to be running frequently especially when done charging. You can check in fan-only mode to see. Sometimes I feel like I catch my Volt just as the battery temp is heating up and it insists on running a battery cooling cycle just as i get underway.

Oh, and with hot temps the A/C can absolutely start to impact range if working hard.

 

[emg77]

I'd put my money on those 2 new tires. I replaced all 4 of mine recently and my range went from 43-44 to 33-34. I gave it a little while and it started getting better after a couple hundred miles. I'm at about 1000 miles on the new tires and I'm back up to 41-42 on the GOM. Still not where I was, but I expected some loss since I went with a better performing tire that isn't LRR. I was a bit worried for a while though.

 

[Ziv]

I got 31 miles of AER a couple days ago with 1 or 2 miles of range left on the GoM. Then I got 36 miles with less than a mile left day before yesterday. Yesterday I got 43 miles before the genset kicked in. I think this may be another version of Tale of Two Volts, in that if you don't use all of your pack capacity often enough, you lose a portion of your pack capacity, but you can get it back by emptying the pack a couple three times.
And my GoM numbers are coming back up again, too. But more importantly, my real world miles are coming back fairly well. I used to get between 40 and 50 miles most days I used my pack entirely, with 43 (maybe 44) being the median. I had a GoM of 42 this morning. Curious to see how many real world miles I get today and what my GoM miles will be tomorrow morning. Thanks for all the ideas! I am not looking forward to seeing what happens to my AER and my GoM in a couple months when I replace the two tires with little tread left.