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Discussion Starter #1
Hi all,

Just had to fill the petrol tank up for the first time (travelled around 750 miles) and wondered if there were a screen or on the app to see how many miles were 'electric'?

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Kia Soul EV 2020
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Only for the current trip, but not possible for "since refuel" or any of the other.

There was a screen that gives you a per cent value on EV vs the whole trip.
 

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Not directly, but if you know your way around a spreadsheet it is easy.

Log into We Connect from a browser. Go to Driving Data, click the More button, then the download button. Select what date range you want and it will then create a spreadsheet with the required data.

Along with everything else you will get a column of electric fuel economy (mi/KWh) and a column of electricity used (KWh). Multiply these together and you will get number of electric miles for each journey. Sum these to get total electric miles 🙂.

There are a few rounding errors but otherwise seems pretty accurate.

The data may default to a text format and need to be converted to numeric format - how to do this will depend on the spreadsheet package you use.

Shout if you need any more info

136701
 

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2020 Passat Estate GTE Advance
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Along with everything else you will get a column of electric fuel economy (mi/KWh) and a column of electricity used (KWh). Multiply these together and you will get number of electric miles for each journey. Sum these to get total electric miles 🙂.
Multiplying these together gives the total distance driven, regardless of electric or petrol driven.

The way this spreadsheet has calculated the "overall consumption figures" columns G and J is to divide the distance covered by the average fuel economy - the distance it uses is the total trip distance which is not broken down into electric distance and petrol distance.

Also, the "overall consumption gal" is actually in litres not gallons (divide by 4.55 to get gallons).

However these overall figures are meaningless. In your 4th line, for example:
1.9 kWh is assuming 39 miles at 20 mm/kW​
3.0 litres is assuming 39 miles at 58.9 mpg​
 

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Yes, my bad, I misinterpreted the column headings and did not check the calculated data properly.🤦

I had not looked at the petrol engine data - the column headings are in the VW data so at least it was not me that got gallons and litres mixed up 🙂
 

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So another approach to provide an estimate of total electric miles.

Filter out all journeys except the ones that are 100% electric. Then calculate the mean of the electric consumption (AVG fuel consumption electric column) just for the 100% electric journeys. With a large enough data set this should give a reasonable estimate.

Then sum the overall consumption KWh column for all journeys and multiply this number by the mean of the electric fuel consumption calculated above.

It is not going to be super accurate but should give an estimate of electric miles.
 

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Discussion Starter #7
Thanks for the answers - I will have a play with exporting the data into Excel.

Seems a bit of an omission that the computer doesn't register this information.

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If I have got the calcs right this time - for me:
Electric only journeys = 87% of journeys
Average electric consumption = 2.9 mile / KWh
Electric miles = 59% of total miles
 

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Discussion Starter #9
If I have got the calcs right this time - for me:
Electric only journeys = 87% of journeys
Average electric consumption = 2.9 mile / KWh
Electric miles = 59% of total miles
What about part electric/part ICE journeys (which a lot of mine are)?

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What about part electric/part ICE journeys (which a lot of mine are)?

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Because of the strange way VW have chosen to calculate fuel consumption you have to make some assumptions.

My 2.9 mile/KWh is calculated from the journeys that I have done that are 100% electric. The assumption is that on a journey which is mixed electric and petrol the electric element of the journey will also be at 2.9 mile/kwh.

This is from a reasonable size dataset (2 years of data) where the speed profile is not massively different between electric only and electric/petrol journeys.

Where I have said that 59% of total miles are electric miles that includes all the journeys completed, electric only and electric/petrol.
 

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Not sure if this is totally correct but the figures sort of tally up.

This only applies for each journey, not per tank of fuel

I use the Zero emissions % figure so if I start off with 100% charge, at the end of the journey whilst driving in Hybrid mode I have for eg 80% zero emissions. Then I take 80% of the total journey miles as being my electric only miles.
 

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These methods are all quite plausible, but how can the distance using both electric and petrol, at the same time, be taken into account? I do not mean GTE mode.

When I am in hybrid, battery maintain, mode there are several instances where both engines are being used (I have the instantaneous consumptions figures displayed on screen). So I think three calculations are needed - ICE only, Electric only, ICE & Electric together.
 

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Do you count the electric motor being used as a generator, as 'electric miles'? In many cases, the GTE uses the electric motor when otherwise driving under engine power to power air conditioning, heating, lights, etc. It's essentially a beefy alternator. The car will charge the battery a little faster than it is normally being used (and regen braking adds to this) so that when you come to a stop, it can run off the battery alone for some time.
 

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I don't think there is enough information in the dataset to be able to calculate anything but a basic approximation of electric (or emission free) miles.

There will be times when both motor and engine are in use, and times when neither are in use (when regen). I think you have to assume that those two 'modes' cancel out and any offset one way or the other is a statistically small part of the total mileage.
 

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Given all the combinations and the complexity of trying to calculate electric miles I think we can see why the spread sheet, or any other method, will not do it. Yes, we can approximate, but a reliable figure is not possible.
 

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Why do you want to know the number of electric miles?
If you did get an answer, what would you do with it?
 

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Discussion Starter #17
Why do you want to know the number of electric miles?
If you did get an answer, what would you do with it?
I'm interested!
No different to knowing mpg. Doesn't change anything but good to know.
I also assumed all Phev vehicles would let you know this information.

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Why do you want to know the number of electric miles?
If you did get an answer, what would you do with it?
Just for interest really. One of the drivers for buying the GTE was to do as many electric miles as possible - interesting to see how that has panned out.
 

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Well, at my prior commute I was driving for 18 months, about 12 miles to work and 12 miles back. At one point I had gone over 3 months on pure EV with religious use of charging at home, work and at the shops.

Now my commute is 24 miles one way, about the same time but 60-70 mph roads and as a result I'm lucky to get into work with 0 miles range and the EV charger isn't yet installed.

Thankfully (given the circumstances) I'm WFH so this doesn't matter so much.

But if your journey to a given location is <20 miles and you have charging at both ends then you can reliably use the GTE as a pure EV, in most cases.
 
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