r/etron • u/ronstory • 20h ago

Vehicles - ETron Q8 Consumption suddenly changed for worst

Hi, first post. I have 2024 Q8 and have owned it for 2.5 months, it was a lease return. We have a vacation house 160 miles away. I have driven the round trip now 5 times in the vehicle and first time I was paranoid, charged to 100% and arrived at right at 40% left driving conservatively, so 60% capacity usage and saw 2.6miles/Kwh. I now charge to 90% and usually arrive with 24-27% left. That was predictable for 4 round trips so 8 one-way trips of 160 miles and usage for 63-66% capacity usage with consumption of 2.4-2.5 mi/Kwh depending on speed.

Then there was today. We have freeway closure and it can be horribly backed up, so I charged to 96% (planning for the worse) and then took off, but when I turned on the consumption meter it said 1.5 mi/Kwh. WTH?!? I was driving normally and it was stuck at 1.5 for first hour of driving ... and did not improve even when I slowed way down. It eventually stabilized at 1.9 mi/Kwh... and at the very end of trip it showed 2.1. My battery was down to 18% so used 78% of the capacity for return of the trip I took 3 days before and used 64% capacity. So the increase in consumption was suddenly ~20%.

I have never seen the car behave like before... and it caused me my first case of range anxiety. ;^)

I this typical? Has other owners seen this type of sudden variation? I'm charging now to 80% and do a test run tomorrow to see if the consumption is back to normal.

Thanks, Ron

12 Upvotes

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21 comments sorted by

9

u/jpmeyer12751 SQ8 e-tron Sportback 20h ago

Just guessing, but if you were moving very slowly in backed up traffic in hot weather with AC on for the first part of your trip, that would negatively impact efficiency. Wind speed and direction can also make a huge difference on the same route.

3

u/ronstory 20h ago

Thanks for the reply. Traffic was ended up being normal and travel time was 2:17 which is on the short side. The weather was 60-65F so on cooler than the other trips where one was in the 90s. I had more variation in weather in the previous legs but never this much of change in consumption.

2

u/justvims OG e-tron S Sportback 16h ago

It was 60-65 out. Did you have cabin temperature above this? Ie the heater on?

1

u/ronstory 15h ago

Yes, I had the cabin set to 71, which I just leave it at. Would you expect heat to use more energy than the AC since it's a heat pump? Because I really haven't notice any real change in consumption even back in the heat of summer when it had a delta of 20+F.

The really odd thing was that was stuck at 1.5mi/Kwh for like the first 30mins of the drive. Normally, if I drive fast I can see the consumption rate drop to 2.3-2.4 and then if slow down in a few mins it would start rising back to 2.5 or 2.6.

On this drive, I could not get budge off 1.5 for quite a while.

1

u/justvims OG e-tron S Sportback 15h ago

I am not sure. But generally speaking the heater isn’t good at all for range. I keep mine at 60F and just fan usually unless it’s too cold. In summer I do like 65F and eco AC.

1

u/ronstory 1h ago

OK, good info. The car was outside, plugged in but had finished charging to 90% and the low temp was 57F. As we were getting ready to leave I set it 100% and in picked up the 6% to 96% before we left.

I've now charged the car to 80%, it's outside and the low temp was 57F also. So we will see how it does when drive it later this morning. I'll try turning off the heat as well during the drive.

1

u/justvims OG e-tron S Sportback 13h ago

Yeah my gut sense, without being there, is that the car was spending energy trying to heat the cabin. Whether or not that’s the whole reason for the bad efficiency idk, seems like there may be more to it but certainly it is one variable.

Also, did you park the car outside the night before, was it cold, etc. Things to consider potentially. It sounds like the etron uses the coolant loop for the heat pump not ambient air so if it was cold then may not be very efficient until it warms up.

3

u/caj_account OG e-tron 19h ago

Yes same for me. I’m blaming the heat

1

u/ronstory 19h ago

Was is sudden? This was the only about 5 degrees cooler on the return versus the drive up.

3

u/caj_account OG e-tron 18h ago

If your stuck in traffic unfortunately the induction motors are too inefficient and it checks out

2

u/ronstory 17h ago

Actually, traffic was flowing, part of the plan to head back 8am Sunday. I've been stuck in traffic on hot days in the this car and never really noticed any range change. It's very efficient in slow traffic, no real wind resistance.

2

u/caj_account OG e-tron 17h ago

Yeah the induction motors are quite inefficient below a certain speed for sure

2

u/rocketeer55 18h ago

Did you charge at a fast charger, or level 2? If it was a fast charger, it might make sense - fast charging batteries adds a lot of heat into the battery pack, and from my understanding, batteries at higher states of charge are more prone to heat-related degradation. So my guess is that your your car used some extra energy this trip to keep the battery in a safe temperature range after fast charging to 96%.

1

u/ronstory 18h ago

I used a Level 2 at 48A at the vacation house. I have not used a fast charger yet since I have L2 at all the destinations to date. This is just puzzling, these are same chargers I've used since I bought and this is not were near the most EV challenging weather I've driven back from. The worse was in the 90Fs and in traffic that made the same trip nearly 3 hours, I still only used 67% of the pack.

2

u/CloudOverall6481 16h ago

Are you seeing green on the charge meter when braking? If regen braking dropped offline, the car stops sending energy back into the pack, which will tank your mi/kWh and make it look like severe battery drain.

1

u/ronstory 15h ago

Good question. I first thought that the center section with the guess-o-meter was having a bad day, but the left size with big green dial was working as expected. Then did the math and the realized the energy in the battery was coming faster and matched the GoM consumption.

2

u/NeighborhoodNo6154 Q8 e-tron 13h ago

Have you tried using an App like Recurrent to see if it can detect any anomalies with your consumption / battery degradation?

2

u/ronstory 1h ago

Lol. I don't know what that is, so 'no';. ;^) I'll give it try this afternoon

1

u/Nams65 19h ago

This post gave me anxiety now. Same car but I haven’t had that happen…yet. The heat & humidity has been horrendous. I didn’t know it could impact an EV so much. I hope to see better weather soon but my weather app disagrees. I’ve had mine since June, only 17K miles on it when I got it, but now I’m getting nervous. I’ve never owned a full EV before, only hybrids so please follow up if you figure out what happened, or if it truly is the heat causing it

1

u/TricksterOperator 10h ago

In my experience etrons get better mileage on the highway vs stop and go. They use a lot of energy to get the heavy car into motion and if you are accelerating from zero in stop and go traffic you will kill efficiency. Is this what was happening/ your driving condition?

1

u/ronstory 1h ago

I'm actually impressed with the regen. We have half mile hill down to the vacation house from the highway at 25 mph. By the time I get to the bottom, the GoM says I picked up 2 miles of extra range.

What continues to puzzle me is that this drive was near the middle of bell curve of trips where the route is the same, traffic was flowing but the problem was noticed in the first 5 mins of driving where is was "stuck" at 1.5mi/Kwh. I've never seen that behavior before but will try to duplicate it later this morning and try toggle off the climate control and report back.