Is your cars maths correct? Mine never is!

[Paulie68]

So what's wrong with this picture?

Well, assuming a conservatively useable 41kWh from the battery, 4.5m/kWh should give me a total of 184.5 miles, but I'm on track for 175.1! I've noticed it's always short. This is in economy too, with no ventilation on so it is the maximum possible range.

So what's everyone else seeing?

 

[Cocijo]

That’s amazing range compared to me. I’ve never achieved more than 150miles. I can get 4.5mpk but as soon as the average speed creeps up it goes right down. Don’t forget you do have some range left when the predicted range says zero!

 

[Jomarkh]

So what's wrong with this picture?

View attachment 3401

Well, assuming a conservatively useable 41kWh from the battery, 4.5m/kWh should give me a total of 184.5 miles, but I'm on track for 175.1! I've noticed it's always short. This is in economy too, with no ventilation on so it is the maximum possible range.

So what's everyone else seeing?

0% on the right 0 on the left?

 

[Paulie68]

That’s amazing range compared to me. I’ve never achieved more than 150miles. I can get 4.5mpk but as soon as the average speed creeps up it goes right down. Don’t forget you do have some range left when the predicted range says zero!

At 10 miles left, the display goes to - - - , you then have 10 miles driving steady, it's not on top of the range left shown unfortunately.

 

[Paulie68]

0% on the right 0 on the left?

Car was stationary at the time

 

[Nibloprice]

The miles left is only guessing really. The first time I got the actual range that it stated at the start of the drive was this weekend in hot weather. Anything below 15degrees and it will start to lose more than a mile per mile of driving. It's very noticeable when driving from dusk into night when the temp drops rapidly.

There are too many things that affect range for the car to predict how many miles you have at the start of a journey. At least for the MG anyway. I imagine what other more expensive cars might do is have more 'spare' miles in the battery that arent shown initially, and make up the difference when the real miles drop too much.

 

[Chrispydoc]

Ive always found my GOM predictions to be very good.

 

[Kithmo]

I must have a 48.5kWh battery on mine, I just topped it up for it's monthly balance and the GOM says 160 miles (in Normal mode with no HVAC) and the m/kWh says 3.3 on both the lifetime average and on the last trip.

 

[Cocijo]

I don’t think that we’ve ever really got to fully understand the algorithms that sit behind the predicted range. I too occasionally have predicted range that appears to have little or no bearing on driving history.

 

[Evie]

In my experience driving/trip history has no impact on predicted range. On trips when I am driving at high speed and with roof box on I lose 1.5km of range for every 1km traveled. It's (mostly) accurate only under "normal" urban driving conditions. It appears they use a constant 'range-per-remaining-kwh' value and ignore driving/trip history.

This is pretty annoying... I'm no expert but it seems like a no brainer to just use the efficiency of the current trip to predict remaining range. Then use a default/constant value only when the trip is reset. That would be far more accurate and prevent the need for frequent mental arithmetic to manage range anxiety.

I read somewhere else on this Forum people saying that MG did factor in driving history. Seems not the case on my Australian purchased ZS.

Whats interesting is now the weather is getting colder as we head into winter here, the stated range at 100% charge is dropping (I assume this is weather and not battery degradation!!). I don't know what effect the cold actually has - is reduced range in cold because the battery capacity is reduced? Or because efficiency is reduced? The former would make more sense based on my theory of how the range algorithm works.

 

[Gomev]

In my experience driving/trip history has no impact on predicted range. On trips when I am driving at high speed and with roof box on I lose 1.5km of range for every 1km traveled. It's (mostly) accurate only under "normal" urban driving conditions. It appears they use a constant 'range-per-remaining-kwh' value and ignore driving/trip history.

This is pretty annoying... I'm no expert but it seems like a no brainer to just use the efficiency of the current trip to predict remaining range. Then use a default/constant value only when the trip is reset. That would be far more accurate and prevent the need for frequent mental arithmetic to manage range anxiety.

I read somewhere else on this Forum people saying that MG did factor in driving history. Seems not the case on my Australian purchased ZS.

Whats interesting is now the weather is getting colder as we head into winter here, the stated range at 100% charge is dropping (I assume this is weather and not battery degradation!!). I don't know what effect the cold actually has - is reduced range in cold because the battery capacity is reduced? Or because efficiency is reduced? The former would make more sense based on my theory of how the range algorithm works.

Others, me included, have noticed that the range seems to be based somewhat on the accumulated trip value. When this is reset predicted range when fully charged and balanced will be 163 miles or 263km regardless., i.e. WLTP figures.

This would suggest that it is basing GOM range on a longer term driving history, your normal average and therefore when driving 'normally' it will predict quite well. However should you load a top box and drive quicker then normal then it won't be so accurate.

Try resetting the accumulated before you start an abnormal trip and see if it gradually works out your new average.

 

[camith1701]

I think the GOM is considering some driving history. My wife drives the MG as if she stole it, while I tend to be more conservative. The predicted remaining range is always much lower after she has driven it for a few trips, certainly lower than the kilometres she actually travelled.

For example, she arrived home yesterday (Sunday) and put the car on charge because it only had 92km of range left. We like to start the week with a full charge. 92km remaining seemed unlikely, so I checked the battery percentage and it still had 50% remaining. Our normal range driving around town, with plenty of regen, is 270 to 280km. We've achieved 300km on a single charge in spring and summer here in Australia. A short predicted total range of 180km is not typical, except when my wife drives with the A/C blasting, apparently.