Guess-o-meter calculations. What is your true range and how much you should trust the car's Algo.

[Rolfe]

Come north!

I was driving up the M74 last month and looked down and saw 92 on the dashboard. I had had no idea I was going that fast. I wasn't the only one though, and we all got away with it.

 

[timeades]

Get a bike!

I have and have been relying on it for the last 5 years when I didn't bother with having a car, for trips where I needed one I used to use zipcar or enterprise car club but those have now been replaced by the MG. At the moment the car only gets used once during the week for the shop and weekends if we want to go further afield but we still do our 20-30 mile cycle on a Sunday, weather permitting.

 

[Rolfe]

Lovely!

 

[okohll]

A slight aside, the other day I tried to get the minimum m/kwh possible, on the motorway, all windows open, heating or sometimes cooling on full, hard acceleration where safe. It ended up as 2.8m/kwh. The most I've seen over a full journey is 4.1 I think, so that's about the range.

The reason was the car charged to 100% when I'd set it to stop at 80, so wanted to run it down a bit as it would be sitting for a few days. At least that process will be a reminder to me to control timing via the charger in case the car doesn't do it properly.

Will check the reported vs. real as above on the next long trip.

 

[RayReliable]

This is my since last chance. All on ECO due to not have charger access for couple of days.

Mixture of 20 - 50mph roads with some 60mph sections. Regen full and autohold on. TJA used at traffic lights.

GoM at start predicted me a 227mile range at 100%

 

[MG4ORR]

I'm driving a trophy since Jan. My GOM reading for over 2000 miles is 4.0 miles/kWh but my geeky spreadsheet computes to 3.4 miles/kWh. Slightly annoying but who cares.

 

[Rolfe]

I think "who cares" about sums it up. I occasionally glance at the miles/KWh but frequently forget. I'm driving the car. I like it. It's costing me in electricity half what it was costing me in petrol. What's not to like?

 

[siteguru]

I'm driving a trophy since Jan. My GOM reading for over 2000 miles is 4.0 miles/kWh but my geeky spreadsheet computes to 3.4 miles/kWh. Slightly annoying but who cares.

If you're like me then your spreadsheet will be calculating two figures ... one based on stored charge (in the car), and the other based on delivered charge (from the wallbox, so accounting for efficiency losses).

 

[MG4ORR]

If you're like me then your spreadsheet will be calculating two figures ... one based on stored charge (in the car), and the other based on delivered charge (from the wallbox, so accounting for efficiency losses).

I'm not quite as geekky as that!

 

[Kithmo]

I'm not so worried about m/kWh as I was with the old ZS now I've got 270 miles range instead of 160.

 

[Rolfe]

I'm not worried at all as I hardly ever drive more than the range of my SR in a day!

 

[RayReliable]

I think range is useful to know for people that do not have home chargers or access for a period of time. For me it’s great to know what I can do if we go away or if I’m not at work where I have chargers access etc.

Stretching range to reduce the cost and pressure of public charging for some might be useful or quite relevant.

 

[fshuk1]

This is my since last chance. All on ECO due to not have charger access for couple of days.

Mixture of 20 - 50mph roads with some 60mph sections. Regen full and autohold on. TJA used at traffic lights.

GoM at start predicted me a 227mile range at 100%

View attachment 18143

Your 4.5 m/kwh is bang on.
I am now getting worried about my car
227 miles on full charge means the car thinks you are doing on average 4.46 m/kwh...... which you are .... well done.

I'm driving a trophy since Jan. My GOM reading for over 2000 miles is 4.0 miles/kWh but my geeky spreadsheet computes to 3.4 miles/kWh. Slightly annoying but who cares.

I refer you to

I remember when I was in my 20s some tourist asked me what is the deepest part of the river Thames. I thought, who cares man. Now that I am, shall we say more mature, I sometimes find myself wondering, WHAT is the deepest part of the river Thames.

It is not about being worried or nervous or geeking on details. It's about understanding and WONDER.

The Moving Finger writes; and, having writ,
Moves on: nor all your Piety nor Wit
Shall lure it back to cancel half a Line,
Nor all your Tears wash out a Word of it.

 

[Tig170]

On the standard version, pretty much 2 x battery % = range left ( a little less in December / Jan )

 

[RayReliable]

Your 4.5 m/kwh is bang on.
I am now getting worried about my car
227 miles on full charge means the car thinks you are doing on average 4.46 m/kwh...... which you are .... well done.

It obviously calculates at the moment and as I was driving carefully I pretty much hit the targets. I added no surprises to the GoM such as aircon or flooring it unnecessarily.

I will conduct the exact same exercise next week but but stay at normal the whole time and see how accurate that is.

 

[MoDolph]

It is not about being worried or nervous or geeking on details. It's about understanding and WONDER.

This. Although, I do like geeking out too.

Everybody likes different things. I like learning as much technical stuff I can find. Some people just want to drive it. Others like to modify it, or perfect the cleaning process. All are fine by me. Life would be boring if we were all the same

 

[Richard P]

A cautionary tale: With under 12 miles to home and the sanctuary of my charger I had 28 miles range showing after a long trip. A bit of a climb over the moor in the dark and my MG5 went into some sort of low battery limp mode with zero range showing. Luckily we were able to crest the hill and regenerate enough on the long descent to get us safely home. Phew

 

[WilkoWanderer]

Ok people, get those calculators out.

We know the guess-o-meter calculates your range using some dark-art-algorithm from your previous-recent driving style. That is not what I would like us to calculate. I have an SR car and when full it shows a range from 236 to 254 which clearly is wrong ( but makes me feel good..... it is good to fool yourself sometime).

Anyway, your quest ( should you wish to accept it) is to use some calculations and compare with the results from FROM LAST CHARGE data. So lets say you charge to 100%. Then drive merrily till you get to 20% battery left. Please do the following calculation.

SR has 50.8 KWh usable battery , so
(50.8 * (1-(20/100)) = 40.64 KWh used
see how many miles you have gone on the From Last Charge screen. Let us assume X
then X/40.64 will be your miles/KWh

Compare this with what is shown in your From Last Charge screen. I bet they will not be the same. Mine had 11% difference.

Now, hopefully the actual miles you have driven From Last Charge is correct (or we are in big trouble) Also 50.8 usable should be quite accurate since our car are newish (note 1 or 2% degradation is nothing, so let's ignore that). So the only dodgy figure is the % of battery left.

So this is the calculation I hope you will do and post some results. This is for fun and don't get worked up about it. If you drive around 4.1 m/KWh on average you should do 210 miles easy (210/50.8=4.1 m/KWh). In town that is easy until we get to winter again. If you do motorway driving I would say account for (3.7*50.8=187 miles) and you cannot go wrong.

You don't have to charge to 100% of course. If you charge to 80% and drive to 20% then the equation becomes 50.8* (1-((80-20)/100))=30.48 kwh used
If you have a long range version use 61.7 instead of 50.8......Simples


I believe the reason for all discrepancies is that with LFP batteries because the voltage across the cells does not drop much from fully charged to discharged, cars are finding it difficult to guess how much battery you have left. This is why MG and TESLA et all say charge your car to 100% regularly, so the system can reset itself.

Of course the long range version uses NCM so the Cells's voltage drops as it discharges and hence the car knows more exactly how much battery you have left. So if you good sires do this example I think your discrepancies should be less than us with LFP batteries.

This is just for fun so whatever the answer, relax and enjoy this wonderful car. So far nothing can touch this car for fun and value.

Thing I have noticed is my range has gone up in the warm weather, however the stated miles per kWh hasn't really changed. Most of the time it is stating 3.6. But there is no way doing that, when check the graph in energy consumption states average 5 mi/kWh which makes more sense.


Anyone else finding this ?

 

[Rolfe]

A cautionary tale: With under 12 miles to home and the sanctuary of my charger I had 28 miles range showing after a long trip. A bit of a climb over the moor in the dark and my MG5 went into some sort of low battery limp mode with zero range showing. Luckily we were able to crest the hill and regenerate enough on the long descent to get us safely home. Phew

I read someone talking about a test (on YouTube I think but I haven't seen it) where they deliberately let some EVs go right down to nothing and they said there was about ten miles of crawling along in tortoise mode between showing zero range and actually coming to a standstill.

I'd be interested in watching that video if anyone knows where to find it.

 

[DrJohn20]

Ok people, get those calculators out.

We know the guess-o-meter calculates your range using some dark-art-algorithm from your previous-recent driving style. That is not what I would like us to calculate. I have an SR car and when full it shows a range from 236 to 254 which clearly is wrong ( but makes me feel good..... it is good to fool yourself sometime).

Anyway, your quest ( should you wish to accept it) is to use some calculations and compare with the results from FROM LAST CHARGE data. So lets say you charge to 100%. Then drive merrily till you get to 20% battery left. Please do the following calculation.

SR has 50.8 KWh usable battery , so
(50.8 * (1-(20/100)) = 40.64 KWh used
see how many miles you have gone on the From Last Charge screen. Let us assume X
then X/40.64 will be your miles/KWh

Compare this with what is shown in your From Last Charge screen. I bet they will not be the same. Mine had 11% difference.

Now, hopefully the actual miles you have driven From Last Charge is correct (or we are in big trouble) Also 50.8 usable should be quite accurate since our car are newish (note 1 or 2% degradation is nothing, so let's ignore that). So the only dodgy figure is the % of battery left.

So this is the calculation I hope you will do and post some results. This is for fun and don't get worked up about it. If you drive around 4.1 m/KWh on average you should do 210 miles easy (210/50.8=4.1 m/KWh). In town that is easy until we get to winter again. If you do motorway driving I would say account for (3.7*50.8=187 miles) and you cannot go wrong.

You don't have to charge to 100% of course. If you charge to 80% and drive to 20% then the equation becomes 50.8* (1-((80-20)/100))=30.48 kwh used
If you have a long range version use 61.7 instead of 50.8......Simples


I believe the reason for all discrepancies is that with LFP batteries because the voltage across the cells does not drop much from fully charged to discharged, cars are finding it difficult to guess how much battery you have left. This is why MG and TESLA et all say charge your car to 100% regularly, so the system can reset itself.

Of course the long range version uses NCM so the Cells's voltage drops as it discharges and hence the car knows more exactly how much battery you have left. So if you good sires do this example I think your discrepancies should be less than us with LFP batteries.

This is just for fun so whatever the answer, relax and enjoy this wonderful car. So far nothing can touch this car for fun and value.

I am in agreement here as I am seeing 270 miles of range after a full charge on my MG5 ev. I don’t want to rely on that but I have to admit it is a bit confusing, especial when I leave my house and have covered maybe 500 yards and I have used 4 miles of power. As I will be making my first long journey to Cornwall in mid July I would appreciate any comments from seasoned ev drivers with MG5 or similar