Don’t you just love the guessometer?

[bigalfromwigan]

I did an overnight balance charge, see picture with 100% charge, range 283. Drove around for a bit and when I got home it was at 96% with 285 range.
Typical! Love that guessometer.

 

[johnb80]

I did an overnight balance charge, see picture with 100% charge, range 283. Drove around for a bit and when I got home it was at 96% with 285 range.
Typical! Love that guessometer.

It depends on how the vehicle was last driven and the conditions, temperature etc. It has to base it's calculations on something so usually it was the previous 15 minutes of a journey. The next journey conditions may be different - higher speeds / temperature etc so it's calculation will change. In my experience (not with MG yet), they are pretty good once you understand what can change their predicted range.

 

[Jomarkh]

Hi, was the second picture taken in normal mode too and was the fan and heater off?

 

[bigalfromwigan]

Yes and yes, I always use normal mode and I had made no changes to any settings. So a level playing field.

 

[johnb80]

Yes and yes, I always use normal mode and I had made no changes to any settings. So a level playing field.

So the 'drive around for a bit' was the exact drive as the day before with the same temperatures and speeds?

 

[bigalfromwigan]

Yes, no difference really. I’m not trying to prove a point or anything, just saying… this is my fifth EV and I have to say the guessometer in essence is becoming more accurate with the newer vehicles/software.
Any newcomers might be informed by this and if somebody takes some knowledge away from this then that’s good isn’t it?

 

[johnb80]

Yes, no difference really. I’m not trying to prove a point or anything, just saying… this is my fifth EV and I have to say the guessometer in essence is becoming more accurate with the newer vehicles/software.
Any newcomers might be informed by this and if somebody takes some knowledge away from this then that’s good isn’t it?

Yes it is absolutely a good thing but the sarcasm kind of gives the game away 'Love that guessometer', followed by the examples of what it showed you. It's absolutely obvious that the vehicle experienced a difference in the energy use between the two journeys for one or more reasons - temperature, speed, location, wind, geography etc. It would have been better to describe to audience what you have experienced and why it happens rather than 'Love that guessometer' if you really as you claim want to help others.

 

[Gomev]

Yes I just love the oddities and quirks of the guess-o-meter algorithm. I believe @bigalfromwigan was being ironic with his comments and making a simple jovial post. Probably not worthy of receiving a lesson on literality or how to make a post, we are all friends here.
We have probably all experienced the 'oddities' after having charged (not to 100% to be clear) of driving a few miles and the range and even the SOC increasing. It always makes me smile.

 

[johnb80]

Yes I just love the oddities and quirks of the guess-o-meter algorithm. I believe @bigalfromwigan was being ironic with his comments and making a simple jovial post. Probably not worthy of receiving a lesson on literality or how to make a post, we are all friends here.

Indeed we are all friends here with a common passion. I often see the so called guess-o-meter criticised, in my view incorrectly as was the case here. Newcomers and other people who dont understand how it works would take it on face value that it's useless where in fact the exact opposite is true. It's a very accurate piece of software that makes it's predictions on historical data. It is in fact much better than the ones that are installed in ICE vehicles but seemingly people accept the range will reduce when they go rocketing the motorway.

We have probably all experienced the 'oddities' after having charged (not to 100% to be clear) of driving a few miles and the range and even the SOC increasing. It always makes me smile.

SOC is usually voltage derived, if temperature increase so can voltage and/of the electronics drift with temperature so not really a big deal.

Sorry if you feel I was being overly critical, I just prefer the bottles half full approach rather than half empty.

 

[Julian Edwards]

I did an overnight balance charge, see picture with 100% charge, range 283. Drove around for a bit and when I got home it was at 96% with 285 range.
Typical! Love that guessometer.

Yes, my MG5 varies by the same small amount. My Volvo V70 ICE car varies by a much greater percentage, as have all my previous combustion engine cars. Okay it would be great if my MG had the 400 mile range of my Volvo, but I find the range prediction on the EV quite reliable. When my MG lease expires in three years I fully expect the average EV will take me 400 miles on a charge.

 

[CuriousIslander]

An interesting discussion.... When I bought the car new 2 years ago I decided I would keep charging records as there was a lot of talk at the time about unreliable GOM readings, and I was interested to what the reality was. If the GOM "learns" from previous driving habits than my car must be a slow learner!

I have a standard range (WLTP 214) Excite original model. Since the beginning of April (when I reset the meters) I have charged 10 times. The GOM predicted range after each charge has always been substantially lower than the actual mileage achieved, due probably to the pretty good weather and favourable temperatures that we have experienced. For instance, after a 100% balance charge the GOM showed 218 miles, whereas on that charge I drove 177 miles and reduced the battery to 37% before the next charge. This gives an estimated total range for that charge of 177/63x100 miles, which works out at 281!! A non-balance charge to 85%, distance driven 102 miles using 40% of the battery gives a range of 255 miles, wheras the GOM showed a post-charge reading of 183 miles. In each case the mileage actually achieved has been substantially more than the GOM would suggest. So does the GOM actually learn by experience, or is this poor learning a "feature" of my particular model of MG5?? Over the 10 charges I have made since April 1st, the post-charge GOM estimate has ranged from 183 to 221, with an average of 202, whereas the actual mileages attained using the extrapolation method above have ranged from 243 to 281, average 259.

I am not surprised that I achieve more than the GOM indicates because I have driven exclusively locally, always, as far as one can tell, in the same (admittedly fairly leisurely) manner and, as suggested above, in favourable weather condtions. However this discussion is about the GOM learning by experience, and the one in my car seems to rather slow to pick up my driving habits!!

 

[johnb80]

I am not surprised that I achieve more than the GOM indicates because I have driven exclusively locally, always, as far as one can tell, in the same (admittedly fairly leisurely) manner and, as suggested above, in favourable weather condtions. However this discussion is about the GOM learning by experience, and the one in my car seems to rather slow to pick up my driving habits!!

It's usually only the previous 15 minutes or so that it uses, not your lifetime

 

[Gandalfharrow]

I guess others have said it, "no different to an ICE car predicting your range", it bases it on how you are driving and how you drove recently.

 

[Jomarkh]

I think the GOM on an EV is more accurate than on an ICE.
I have taken my MG5 to less estimated range than any ice I have owned.

 

[johnb80]

I think the GOM on an EV is more accurate than on an ICE.

I totally agree

I have taken my MG5 to less estimated range than any ice I have owned.

ICE vehicles have difficulty in measuring accurately the fuel in the tak, slight inclination etc it's a nightmare wheras the capacity remaining in the battery is relatively easy to measure and therefore calculate the range but it has to base it's calculations on historic data i.e. previous driving. It can measure and take into account environmental conditions, my i3 also takes into account the road types and terrain if you put a destination in the sat nav.

 

[1MGEVUSER]

I am getting used to the estimated mileage displayed on the center console of my new ZS SR. It's understandable that any variables will change the outcome, but it's the same for ICEs.

Just come back from a joy ride around small villages. A round-trip of 35 miles and I am amazed to see a 4.8 miles/kW. The best so far! This was on ECO, sunroof fully open including the front 2 window and 3 people onboard. Happy days!

 

[MG4ORR]

When quoting miles/kWh as 4.8 miles/kWh in the post above from 1MGEVUSER, is that actual from total miles divided by total charge or as per display? In my case, MG4 Trophy driven mostly in ECO mode, the on board reading is 4.2 miles/kWh whereas the actual spreadsheet performance is 3.4 miles/kWh Why? Irrespective I am loving the MG4 at 4.5p/mile for 3,000 miles - charging at home from mostly solar when the sun is out!

 

[1MGEVUSER]

When quoting miles/kWh as 4.8 miles/kWh in the post above from 1MGEVUSER, is that actual from total miles divided by total charge or as per display? In my case, MG4 Trophy driven mostly in ECO mode, the on board reading is 4.2 miles/kWh whereas the actual spreadsheet performance is 3.4 miles/kWh Why? Irrespective I am loving the MG4 at 4.5p/mile for 3,000 miles - charging at home from mostly solar when the sun is out!

Not the total average but just the last journey of 35miles at low speeds. I have just started to use the ECO mode and I like the results.

 

[rogerco]

I don't have any problem with the (implied) sarcasm in the OP title "don't you just love the guess-o-meter". I've had my SR for over 2 years now and very quickly learnt to ignore the GOM - the new information above is that it uses the previous 15 miles as a baseline - I've never seen that mentioned before and I wonder if you have a reference for it, or inside knowledge? (maybe it is mentioned in the handbook for the later versions - certainly nothing in my handbook).

Since I don't normally look at the GOM I can't be sure, but my impression is that its not as simple as that (although that would be pretty simple to implement in software). Certainly I've done trips early on where the GOM did not track the actual road conditions and mental arithmetic on the rate of change of the SOC over the last few miles.

My impression was that at the start of a trip it would report range as [notional range ie 216] times [SOC], and would very gradually once SOC got below about 50 catch up with real world conditions. But I could be wrong.

In practice simply looking at rate of drop of SOC and/or miles/km (which is obviously an average over some period of time or distance unknown) and dong an engineering estimate (ie ignore least significant digits and add a 10% margin of error in the unfavourable direction) of likely range is pretty reliable. And the mental arithmetic keeps you awake, which is good.

 

[Gomev]

When quoting miles/kWh as 4.8 miles/kWh in the post above from 1MGEVUSER, is that actual from total miles divided by total charge or as per display? In my case, MG4 Trophy driven mostly in ECO mode, the on board reading is 4.2 miles/kWh whereas the actual spreadsheet performance is 3.4 miles/kWh Why? Irrespective I am loving the MG4 at 4.5p/mile for 3,000 miles - charging at home from mostly solar when the sun is out!

Where are you getting your spreadsheet info for number of kWh used ?