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Discussion Starter · #1 · (Edited)
Been mucking about with a speadsheet to compare an i3-Rex figures to my current Honda Civic 2.2 i-dtec looking back over the last 12 months to gauge getting one for the future.

Averaging about 100 miles a day, some under 70 miles, some way over 70 miles. Will most liklely only charge at home, doubt will be allowed to charge at work and wont include possible rapid charges at service stations as they cant be gaurented.

Anyway, can some real world i3-Rex owners give me some real world (other than BMW marketing) figures!

Driving will either be heavy traffic 7am-9am and 4pm to 6pm, the rest will be 60mph A roads and 70 MPH Duel carraigeways / Motorways. on these roads I generally set cruise to 60 and 70 and let those in a hurry pass me by.

I have put in for these driving conditions;

70 mile range on a full overnight charge ?

40 MPG economy on the REX above 70 miles EV range ?

£2 overnight charge cost @ 11p a KWH.


Realistic figures or way out?

BTW these will be late summer / Early Autumn figures, as we wont have real world Winter / Early Spring and full Summer figures yet!


M
 

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I'd say that they are fairly sensible figures.

In normal driving situations I get around 65 miles in comfort and 70 in Eco Pro from a full charge.

REx was bang on 45mpg on a motorway sat at 62mph. So probably 40 or so if you cruise at 70mph...
 

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Discussion Starter · #3 ·
I'd say that they are fairly sensible figures.

In normal driving situations I get around 65 miles in comfort and 70 in Eco Pro from a full charge.

REx was bang on 45mpg on a motorway sat at 62mph. So probably 40 or so if you cruise at 70mph...
Plus I will be able to take some 1hr fast charge lunchbreaks at services if available and some 13amp plug EVSE charging at work in summer months when the dont mind cables trailing from location doors and windows.

Really need a big boss go EV so they fit outside plugs and dedicated EV charging or full 32amp tethered chargers. But as they drive Range Rovers and Sports ICE cars cant see that happening as they dont travel loads and dont give a stuff of their motoring costs as the company swallows it.

I asked in 2012 about an Ampera in 2013 and charging at locations and the companies pence / kwh etc to pay then back and they gave the figures but where really offish about buying "Electric Cars" for company use and charging at work / customers etc. So I shelved the idea and got the Civic until the right EV came along, 70+ EV miles range, with and Extrender REX and fast charge capable. And it arrived with the I3- REX.

M
 

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i3 with Range Extender (EREV) Sept 2014
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I will post stats on a monthly basis if that helps?

So far averaged 74 E miles without thinking too much about it, sticking to speed limits, plus when nearly home having fun in Comfort mode :eek:
 

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Discussion Starter · #5 ·
I will post stats on a monthly basis if that helps?

So far averaged 74 E miles without thinking too much about it, sticking to speed limits, plus when nearly home having fun in Comfort mode :eek:
Cool that would be great. Can you confirm the BMW data that it takes 18.8 kWh to fully charge from empty?

M
 

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i3 with Range Extender (EREV) Sept 2014
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Cool that would be great. Can you confirm the BMW data that it takes 18.8 kWh to fully charge from empty?

M
Not sure about from empty as far as REX starts at 6.5%, recently left with 7 E miles saying 13% SOC and the charger stat for that night was 18.23kWh so sounds about right.
 

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£2 overnight charge cost @ 11p a KWH.
I am not a real world i3 owner but I thought that you may be able to work on the 11p/KWh figure. We had a Leaf on a one week test drive which I reckon cost us about £1 to fully charge from empty on economy 7 overnight.
Also if you have the Rex you can't get the heat pump. This may have an effect on EV range if you need heat, demist or cooling.
I love these cars. I was also wondering whether LEDs would help range.
 

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I reckon you would get nearer 80-90 miles with those driving conditions e.g. heavy traffic and cruising at 60 mph. The normal heater does not take much off the range. This morning I had the heater set (eco pro mode) at warm 22C, it was 5C outside, and the predicted reduction on my total range was 2 miles.
 

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I've been surprised how little predicted range drops when using a/c or heater. It seems much less than the Leaf. Whether this is realised in practice remains to be seen.
 

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Discussion Starter · #12 ·
I reckon you would get nearer 80-90 miles with those driving conditions e.g. heavy traffic and cruising at 60 mph. The normal heater does not take much off the range. This morning I had the heater set (eco pro mode) at warm 22C, it was 5C outside, and the predicted reduction on my total range was 2 miles.
Would only be criusing @ 60 on single lane A roads. For sure where i can all duel carriageways and motorways will set the cruise to 70. Dropping to 60 on 70 limits just seems to slow for me, like im turning into my Dad who is managing to average over 70 mpg in his 2013 Honda Civic 1.6 i-dtec for thje 1500 miles he has put on it the last 2 months.

Not quite ready for that yet, maybe will turn into a true captian slow in another 5 years when i pass 50! One thing I do notice driving the wifes Volt locally on weekends when I have a whole 30 miles range to waste each day, I have regained the love of zooming everywhere around town, high acceleration and later braking, without thinking of the fuel cost, pretty much as I did when I had my A reg mk1 XR2 in my early 20's!!

M
 

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Discussion Starter · #14 ·
Cruising at 70, I would expect a 70 mile range, so REx will kick in at 65 miles.
Ah..... so the i3 system calculates range with REX differently to the Volt/Ampera ? With the Volt the "range" displayed when you first start up on a full charge is the pure EV range after which the Extender kicks in, so if it says 30 range and you don't hammer it you will go 30 miles and then the engine will take over once battery range is exhausted.

You are saying on the i3 the estimated EV range does not take account the small % of battery it has to hold back to run on the REX?

So another mod on the spreadsheet then, because I need the i3 REX Pure EV range @ 70 mph, before the rex cuts in. I will drop that figure from 70 to 65. Seems a strange way to estimate Pure EV range though, ignoring the REX buffer it needs to hold back.

M
 

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That's right, it uses the last 6.5% of charge as a buffer - so you may eat into that depending on power requirements.

You can use the full 100% if you want - just empty the fuel tank!
 

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i3 with Range Extender (EREV) Sept 2014
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Ah..... so the i3 system calculates range with REX differently to the Volt/Ampera ? With the Volt the "range" displayed when you first start up on a full charge is the pure EV range after which the Extender kicks in, so if it says 30 range and you don't hammer it you will go 30 miles and then the engine will take over once battery range is exhausted.

You are saying on the i3 the estimated EV range does not take account the small % of battery it has to hold back to run on the REX?

So another mod on the spreadsheet then, because I need the i3 REX Pure EV range @ 70 mph, before the rex cuts in. I will drop that figure from 70 to 65. Seems a strange way to estimate Pure EV range though, ignoring the REX buffer it needs to hold back.

M
I think 70 E miles should be more or less right, no way you can do constant 70 mph for 70 miles in UK.
 

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I’d just come through a heavy but localised rain storm on the M20 when the i3 started to slow. It was a gradual process, from motorway cruising speed all the way down to 44mph. By this time I was travelling up a slight incline and had effectively become a slow-moving obstacle. Lorries were catching me with quite frankly terrifying closing speeds. It was three or four minutes - which was long enough to make me consider pulling over - before the i3 recovered; just as slowly as it had lost speed, so it crept up.

“It’s not a limp-home mode as such,” a BMW spokesman later told me, “but once the charge runs down to five or six per cent and the range extender cuts in, if you keep driving at 75-80mph it can’t maintain the charge.” Rather than damage the battery by running it completely flat, the i3 had restricted our performance.

What I should have done, it transpired, was engange the range extender when there was still 30-40 per cent charge in the battery. Still, the car had covered my mistake, albeit in a slightly alarming fashion, and the remainder of our journey back into London went without a hitch (save needing to add another 7.5 litres of petrol).
i3 owners is that right or is that not true? I know 75mph or 80mph is above speed limit but is it the same at 70mph or no such problems?

Source from http://www.telegraph.co.uk/motoring/car-manufacturers/bmw/10440292/BMW-i3-Range-Extender-review.html
 

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I've been surprised how little predicted range drops when using a/c or heater. It seems much less than the Leaf. Whether this is realised in practice remains to be seen.
@Brian Stanier The Gen2 Sunderland built LEAF Acenta and Tekna models are also very efficient with their heat pump technology. The Gen1 Japanese model did not have a heat pump, only a PTC ceramic 'toaster' style heater, hence the huge range loss.
 

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i3 owners is that right or is that not true? I know 75mph or 80mph is above speed limit but is it the same at 70mph or no such problems?

Source from http://www.telegraph.co.uk/motoring/car-manufacturers/bmw/10440292/BMW-i3-Range-Extender-review.html
I understand this story to be embellished a little.
An I3 owner on here with some 'motoring skill' has tried a few times to replicate this, and despite working the car very hard, was unable to get anything like that level of performance drop.
His point was that he purposefully drove it way beyond the normal realms of driving speed and style to get 'any' level of performance hit.
:)
 

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I think that driving at 80mph, in heavy rain, and up a slight incline, could well result in significant loss of power.

But a little bit of forethought, with some adjustment of driving style depending on conditions, would avoid this scenario.
 
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