[monty]

So, I was wondering what brainiac or team wrote the GOM algorithm?

I guess we all know it is pretty inaccurate. 25-50% by my reckoning.

Today, I charged to 80% and it said 211 miles.
My average over the 1700 miles is 3 miles /KWh
So, do I have a magical 80 KW/hr battery?

Do we really think it is going to get any better??

 

[FelineFreddie]

There are just so many variables in play (driving style, road and weather conditions, just to name a couple) for it to be anything more than a guess. A much better indicator would be battery state-of-charge %, IMO.

 

[JayEM]

Was that projected 211 miles with the climate control (HVAC) off, in Eco mode, or Auto? Was your average 3.0 mi/kWh achieved using the same setting?
Just turning the HVAC from off to Eco will drop the projected range by around 25% (why THAT happens is somewhat of a mystery, but the projected "off" range appears to be the most unrealistic available).

After I last charged my car to 100% (end of February), the Eco (HVAC) projected range was in the 220-230 range. After driving 77 "suburban" miles (some highway, some traffic, mostly under 50 MPH) the SOC is down to 63% and the projected total range in Eco HVAC mode is still between 220 and 230 miles (temps mostly in the 30-50 F range). And the displayed efficiency for those 77 miles is also 3.0 mi/kWh (some trips higher, some lower). The projected range with HVAC off is much higher but since I don't drive it that way I ignore that number (unfortunately that's the number the app uses).

As @FelineFreddie has observed, "guesstimating" driving range is a challenge (since your future driving cannot be known). It's best not to count the available miles shown as "in the bank", but the current SOC % is a much more dependable figure. It will be nice WHEN that item is added to the instrument panel display (I'm going with WHEN not IF at this point).

 

[FelineFreddie]

I suspect the GOM is a holdover from the traditional “miles to empty” equivalent on ICE vehicles.

Can you imagine what folks would say if their ICE vehicle only displayed “XX%” of fuel remaining in the tank, and drivers actually had to calculate the estimated miles left before empty?

 

[R P]

I use the GOM as a very rough guide. And I take into account that it is always optimistic. I have been going to the same ski resorts over the past couple months and charged at the same locations (L3s) both up and down the mountains. And the consumption and real range have been fairly consistent with each trip. So at least I have real experience to better gauge and plan my trip times and charging enroute.

For my trips (about 400 km) return, the required charging times have been tolerable, esp given that the enroute chargers are all free. Unfortunately my fav hill does not have an L2 charger onsite. If it did I could make the trip with only one charge. As it is, a partial charge (L3) is needed before I get there and then on the way back. A couple of the other hills I go to have L2 chargers onsite, but you have to be early to get one, as I am certainly not the only EV driving there. But because I like to catch the early morning powder before it is skied out, I usually do get there before they are all taken.

 

[monty]

Was that projected 211 miles with the climate control (HVAC) off, in Eco mode, or Auto? Was your average 3.0 mi/kWh achieved using the same setting?
Just turning the HVAC from off to Eco will drop the projected range by around 25% (why THAT happens is somewhat of a mystery, but the projected "off" range appears to be the most unrealistic available).

As @FelineFreddie has observed, "guesstimating" driving range is a challenge (since your future driving cannot be known).

It's climate control off (which is what the app says). The range is what I get as soon as I power on after charging. I have been in eco mode for driving 99.9% of the time.
My point is, if my average is 3 mi/KWH and the battery is 80% of 70(65?)KW/hr why doesn't it show 168 miles? I think possibly one short trip I noticed the range around 4 mi/KWH

I believe the mi/KWh isn't the total power usage either. It doesn't seem to account for the climate control - I find that a bit misleading. I'm also thinking the heated seat and steering wheel come off the 12V battery? Which of course is supplied directly or indirectly from the traction battery but how much does that impact SOC?

I suspect the GOM is a holdover from the traditional “miles to empty” equivalent on ICE vehicles.

Can you imagine what folks would say if their ICE vehicle only displayed “XX%” of fuel remaining in the tank, and drivers actually had to calculate the estimated miles left before empty?

In the wife's audi and even in the legacy - I'm pretty sure the miles to empty was a lot more accurate. Admittedly, I didn't bother for the most part until somewhere between 50-100 miles left then I'd think about when I'd be in the vicinity of my favourite gas station.

 

[JayEM]

It's climate control off (which is what the app says). The range is what I get as soon as I power on after charging. I have been in eco mode for driving 99.9% of the time.
My point is, if my average is 3 mi/KWH and the battery is 80% of 70(65?)KW/hr why doesn't it show 168 miles? I think possibly one short trip I noticed the range around 4 mi/KWH

I believe the mi/KWh isn't the total power usage either. It doesn't seem to account for the climate control - I find that a bit misleading. I'm also thinking the heated seat and steering wheel come off the 12V battery? Which of course is supplied directly or indirectly from the traction battery but how much does that impact SOC?


In the wife's audi and even in the legacy - I'm pretty sure the miles to empty was a lot more accurate. Admittedly, I didn't bother for the most part until somewhere between 50-100 miles left then I'd think about when I'd be in the vicinity of my favourite gas station.

It's not showing 168 miles @ 80% because it's using "HVAC off" as its standard. Since that's now how you've been driving, it's not assuming 3.0 mi/kWh but rather something more like 3.8.

On a recent trip (mostly highway, 176 miles) the display said I had averaged 2.6 mi/kWh. The calculated rate of consumption (one L3 session at E-A (25.74 kWh) and one L2 session at home on my ChargePoint Home Flex (43.02 kWh)) worked out at 2.56 mi/kWh which rounds to 2.6 - so I think that's pretty close (I know, only one data point).

 

[monty]

It's not showing 168 miles @ 80% because it's using "HVAC off" as its standard. Since that's now how you've been driving, it's not assuming 3.0 mi/kWh but rather something more like 3.8.

On a recent trip (mostly highway, 176 miles) the display said I had averaged 2.6 mi/kWh. The calculated rate of consumption (one L3 session at E-A (25.74 kWh) and one L2 session at home on my ChargePoint Home Flex (43.02 kWh)) worked out at 2.56 mi/kWh which rounds to 2.6 - so I think that's pretty close (I know, only one data point).

I don't quite follow what you mean.

I don't why it would be using 3.8 for the GOM - that was an anomaly given the average is 3.0. My 27 mile trip to work this morning was 2.7. I guess I could reset the mi/KWh usage, but 3.0 is the highest I've seen that.

According to the app, I'm now at 56% with 145 miles. So, I used about 24% to do 27 mile - no climate control, some heated steering wheel.
No way that I'm getting 145 miles on the SOC. If it took usage for the last trip, it should be about 105, if it took the average of 3.0, it would be about 117. If it used the total amount of power used, it would show (27/24*56) 63 - which is a lot more realistic.

 

[JayEM]

3.8 is just the mi/kWh it would take to achieve 211 miles if 3.0 gets you 168. If driving with HVAC in Eco mode gets you 3.0 then conceivably driving with HVAC off would get you 3.8 - or at least conceivably that's what the car would expect.

I'm not defending the way the GOM was programmed, just attempting to explain why it gives one number under one scenario and a much lower number under a different one.

On my last EV, I did notice that the GOM changed when I used the nav. If it had a specific destination entered, it was able to give me a more reliable prediction of how many miles I'd be able to drive.

Having driven 2 prior EVs over the last 6 years, I've come to understand what the changing numbers mean and, more importantly, what they don't mean. Only on the first trip I ever took did I take the GOM literally (almost didn't make it home, driving into a strong headwind at highway speeds). Now I use the SOC as my guide - "how many % do I need to do this trip?", not "does it say I have enough miles to do this trip?".

 

[lenny]

I use the GOM as a very rough guide. And I take into account that it is always optimistic. I have been going to the same ski resorts over the past couple months and charged at the same locations (L3s) both up and down the mountains. And the consumption and real range have been fairly consistent with each trip. So at least I have real experience to better gauge and plan my trip times and charging enroute.

For my trips (about 400 km) return, the required charging times have been tolerable, esp given that the enroute chargers are all free. Unfortunately my fav hill does not have an L2 charger onsite. If it did I could make the trip with only one charge. As it is, a partial charge (L3) is needed before I get there and then on the way back. A couple of the other hills I go to have L2 chargers onsite, but you have to be early to get one, as I am certainly not the only EV driving there. But because I like to catch the early morning powder before it is skied out, I usually do get there before they are all taken.

Exactly the same scenario I'm rolling around. 200km to the ski hill one-way; my current ICE could do 400km on its own, have a deposit but no delivery on a Solterra yet. Is the extra time and uncertainty over charging, charger availability and charger state of repair worth it?

In a way, I hope this deposit lags until the 2024 model year when there might be some enroute preheating, for instance, as outlined here (list of proposed changes) and here (mention of possible preconditioning [with hardware changes needed] and Subaru battery testing). But I can't necessarily count on miracles in one model year. In this video of the frame and battery system, he comments how the on-board 6.x kW recharger seems to be borrowed from the Toyota hybrids, and that the battery cooling and preheating channels are unusually small vs. competitors. Looks like a major and expensive change, not a dealer fix.

So, really nice driving car (with some fun new toys vs my reliable dinosaur), except for the electric part, and might be a waste of money vs. holding off for a few more years. But that's a long ways away! Do you have regrets?

 

[BinPNW]

...Now I use the SOC as my guide - "how many % do I need to do this trip?", not "does it say I have enough miles to do this trip?".

JayEM, how much kW do you assign to a percentage point?

 

[JayEM]

JayEM, how much kW do you assign to a percentage point?

I don't really do that, I just figure my efficiency in "miles per percent". So 2 miles per percent = 200 miles on a full charge. But kinda hard to do in an EV without a % SOC display.

 

[ajpascucci]

It's not showing 168 miles @ 80% because it's using "HVAC off" as its standard. Since that's now how you've been driving, it's not assuming 3.0 mi/kWh but rather something more like 3.8.

On a recent trip (mostly highway, 176 miles) the display said I had averaged 2.6 mi/kWh. The calculated rate of consumption (one L3 session at E-A (25.74 kWh) and one L2 session at home on my ChargePoint Home Flex (43.02 kWh)) worked out at 2.56 mi/kWh which rounds to 2.6 - so I think that's pretty close (I know, only one data point).

At 80 % charge miles range 184. In warmer weather I get around 194 miles total.
At 100 percent its varies from 256 to 274 total.
I have need 303 total since delivery. Waiting to see numbers in Summer.

Religiously charging only to 80 percent. I typically take 184 miles down to 35 to 50 miles charger up at night. If drive alot which I do charger on free chargers walk home. Typical charge is 2 hours to 5 house of whats soc when arrive.

 

[R P]

Exactly the same scenario I'm rolling around. 200km to the ski hill one-way; my current ICE could do 400km on its own, have a deposit but no delivery on a Solterra yet. Is the extra time and uncertainty over charging, charger availability and charger state of repair worth it?

In a way, I hope this deposit lags until the 2024 model year when there might be some enroute preheating, for instance, as outlined here (list of proposed changes) and here (mention of possible preconditioning [with hardware changes needed] and Subaru battery testing). But I can't necessarily count on miracles in one model year. In this video of the frame and battery system, he comments how the on-board 6.x kW recharger seems to be borrowed from the Toyota hybrids, and that the battery cooling and preheating channels are unusually small vs. competitors. Looks like a major and expensive change, not a dealer fix.

So, really nice driving car (with some fun new toys vs my reliable dinosaur), except for the electric part, and might be a waste of money vs. holding off for a few more years. But that's a long ways away! Do you have regrets?

All depends on why you are looking to get the Solterra. It is NOT a good trip car with its lower range and slow charging. But if you want an off-road and snow capable EV, the Solterra is good for that. But then you should have another vehicle available for longer trips.

Currently, I have an ICE car for long trips, but have a long range fast charging EV on order (Ioniq 5) that will then also be capable for long trips. We need two cars anyway between us, so our complementary needs will then be met by just having two BEVs.

 

[monty]

3.8 is just the mi/kWh it would take to achieve 211 miles if 3.0 gets you 168. If driving with HVAC in Eco mode gets you 3.0 then conceivably driving with HVAC off would get you 3.8 - or at least conceivably that's what the car would expect.

The issue is that I'm driving in eco driving mode and for the 150 minutes of driving, I'm using HVAC for 30 minutes. If I was using it the whole time, I wouldn't make the trip without charging.
I have a longer trip I'm taking this week, and know that I will have to charge enroute. I'll charge to 100% and reset my.mi/kWh and I'll be curious to see how that changes anything.

 

[monty]

So, it's almost like magic. I noticed this week the GOM was showing a lot lower on an 80% charge.

I recently had a 220+ mile trip to do in 24 hours. I figured I'd need to charge enroute and was planning on a DC charger. In the end I charged to 100% overnight and remote started while still connected to the charger. I charged twice at free stops. One was on the way at a level 2 for 15 minutes or so, so pretty pointless. My plans changed and I ended up charging at a library on a free level 2 for 3 hours - did have to wait 90 minutes to get a spot.

Being bit of a nerd, I tried recording some numbers. I may have scribbled some down wrong. Topping out at 65mph, but often below that and at 35-50F I was pleasantly surprised. The GOM started at 266 - not the 300+ I'd previously seen and tracked much closer than what I'd been seeing before.
The orange below is what I drove, the blue is what I drove according to the GOM. The last section was this morning at about 30F - and I did relent and have the steering wheel heat on low.

Cumulative Distance	Since last charge	SOC	Range	Range used
0​	0​	100​	266​	0​
14​	14​		248​	18​
49​	49​		198​	68​
100​	100​	54​	142​	124​
103​	0​	55​	141​	0​
184​	81​	17​	39​	102​
185​	0​	45​	115​	0​
194​	9​		88​	27​
223​	27​	25​	52​	63​

​

​

​

​

​