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Range vs mi/kwh

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4.3K views 25 replies 7 participants last post by  Hermit Dave  
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#1 ·
Getting used to this new car and i'm struggling a bit to get my head round the range and consumption.

Previous car was a Mercedes B250e. 28kwh usable, but not the most efficient of shapes and an EPA range of 85 miles. My commute is about 38miles, of which about 3/4 of it is free flowing motorway and i'm usually found in the outside lane doing 70 (on the GPS) The merc would use "about half" the battery getting to work on a good day, and approaching 70% used on the coldest winters days. Charger at work so no issues there.

My best ever journey managed about 90miles which was a fairly steady jaunt on some A roads, keeping to a maximum of 60 and generally being pretty gentle with the throttle. Not my favoured style, but i tried it to see what it would do.

So enter the LEAF 30.

EPA range is 100miles, so compared with the Merc i expected it would go a bit further. Even with similar capacity this makes some sense as its a lower, lighter car with a much more aerodynamic shape. Its showing 12 bars and Leafspy said (from memory) 95% SOH.

I've reset the average consumption meter a few times, and my driving seems to hover around 3.2-3.3 mi/kwh. Based on the LEAF 30 having 28 useable when new and 5% degredation, one imagines about 26.5kwh available now, and thus a range of about 85miles. When fully charged the car seems to like to suggest 100+ miles of range on the GOM.

I've had a few journeys recently however, where the cars really fell short of that.

At the weekend for instance i did 89 miles round trip. Almost all of it on the motorway. First leg was 43miles, started at 100%, arrived in the mid 40's. Did maybe 5 or 6 miles of town driving here and there. Then set off home. Drove to a nearby rapid, and charged from 39% to 63%, which ABRP said would be enough. Drove the 43miles home, which involved a small detour and i stuck to indicated 70 rather than "GPS 70" instead, and rolled into the driveway with the battery guage on ---%. That means 89 miles used all of the battery, plus the extra 25% top up from the charger.

That suggests nearer 2.6-2.7 miles per KWH? Yet the dashboard is still happily displaying 3.3mi/kwh.

Similarly last night, i drove to my folks 35miles away, having left with about 90% and arriving in the low 40's. Plugged in and charged to 63% with the granny. Drove home later and got in with low battery warning and 6% on the gauge. But again, 90 to 40, then 63 to 6, means i've used 107% to drive 70 miles?! Again that seems like its down in the 2.5-2.6 mi/kwh range, yet, again, the dashboard is showing 3.2. I've setup the App as well, and for yesterday its showing 77mi (the other 7 miles were some town driving in the morning which is why i set off with 90 and not 100%) and 3.2mi/kwh, and a total consumption of 23.82kwh.

These numbers dont really seem to add up?

Thoughts?
 
#2 ·
Leaf30 struggles with efficiency when driving over 63mph.

Oh and it isn't as aerodynamic as you might think. It had a Cd of 0.32 if I'm not mistaken.

I don't know why you think Leaf would be more efficient than B250e (which is tesla tech underneath). We do sufficient miles in Leaf and average 4+ mile / KWh.

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 
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#5 ·
Hermit Dave said:
Leaf30 struggles with efficiency when driving over 63mph.

Oh and it isn't as aerodynamic as you might think. It had a Cd of 0.32 if I'm not mistaken.

I don't know why you think Leaf would be more efficient than B250e (which is tesla tech underneath). We do sufficient miles in Leaf and average 4+ mile / KWh.

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
Click to expand...
Well both NEDC and EPA say the LEAF is more efficient than the B250e. And just looking at the cars, the B250e is tall with huge frontal area, the front end of its almost van like. even with the same Cd, the B250e will have more drag due to its larger frontal area. Its also several hundred kilos heavier.

I get that driving quickly uses more energy, its simple physics. I'm happy with that. If it were actually doing the reported 3.2mi/kwh i wouldnt have a problem. I dont expect to get 4mi/kwh out of it.

the issue is the disconnect between what the car is reporting its consuming and real world. The app reports my average yesterday was 3.2mi/kwh and says i used 24kwh in total but yet i had to charge it adding 20% or i'd never have made it home. Had it actually only used 24kwh it should have made the trip without charging at all, with energy to spare?
 
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#6 ·
I've not checked tyre pressures, i assumed it has a TPMS and would be fine. But i will check them tonight.

Tracking i've been meaning to look into, the wheel is very slightly out of centre. Theres also a high speed vibration that feels like wheel balance or maybe a bent rim. A job for the weekend.

I will also get LeafSpy going while driving, maybe at the weekend when i can get the wife to drive.
 
#4 ·
Remember the battery size Nissan advertises is total capacity. Usable capacity will be closer may be even less than your B-class.

As said, driving Leaf at high speed will see its range disappear. Try staying below 65 indicated speed?

I've never took much notice of the car's reported consumption or GOM. I just get a feel of its range and go by the % reading.
 
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#7 ·
wyx087 said:
Remember the battery size Nissan advertises is total capacity. Usable capacity will be closer may be even less than your B-class.

As said, driving Leaf at high speed will see its range disappear. Try staying below 65 indicated speed?

I've never took much notice of the car's reported consumption or GOM. I just get a feel of its range and go by the % reading.
Click to expand...
Agreed, and as i said in the first post, theres potentially only 26-27kwh available, which is likely less than the Merc had. It just feels like its using waay more than its reporting that its using. If it is indeed very inefficient at that speed and is using 2.6mi/kwh, then so be it. But its reporting 3.2, which "feels" more right. Economical drivers seem to get up into the 4's, so low 3's doing 70 seems to be about where things should lie?
 
R
#18 ·
When I bought my used 30kWh Acenta in June, I was unhappy with wandery steering on the motorway, my local tyres place tracked it (twice, eventually), did tyre pressures check, is spot on now. Also got them to activate car, click to "N" while 2 of us tried pushing/ pulling the car on their dead-level concrete floor, to check for any brake bind or wheel-bearing drag. Was nice and free, and have been achieving some reported 5+ miles per kWh over summer. So those checks def worth doing (good investment of £30, they didn't charge me 2nd time, as no adjustments needed.) Must add, that's in B mode and harnessing c50yrs of hyper-miling knowhow!
At some point soon, BEVs will start to come equipped with a 2-speed transmission, which will auto-shift at about 45mph, to combine low-speed responsiveness with longer range at cruise speeds. Cool! Recall it's ZF/Borg Warner who've developed it.
 
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#19 ·
A short update on this. Still fairly disappointed with the range, though at least its predictably poor.

I ran leafspy this morning on my drive to work so captured some data.

At start the battery was showing 100% on the dash and i think 97 or 98% SOC on leafspy. It showed 27KWH available (343 GIDs from memory), and the cell variation was 14mv.

I drove 39miles to work, typical mix of motorway (driving at an indicated 77, or about 70 in the real world) and a fair amount of congestion and slow moving traffic in the last 10miles or so. Heating on at a comfortable 22c. Arrived with exactly 50% SOC remaining.

The nissan app reports 3.2mi/kwh for the journey.

Leafspy shows i consumed 12.5kwh which is around 3.1mi/kwh. Cell variation was 13mv, so nothing too funny going on there.

So most of that makes sense.

However when i arrived, leafspy was showing 13.7kwh remaining, and clearly 13.7 plus the 12.5 i've used doesnt add up to 27. It was also showing 177GIDs, which doesnt match the 13.7kwh remaining, and the 166gids consumed doesnt match the 12.5 its said i've used. Plus if its at 50% SOC, how can it only have used 12.5kwh?

i realise its all fairly close and theres bound to be errors, but theres nearly a kilowatt hour gone missing already if its showing 50% SOC having only used 12.5. If that continues, then clearly by the time i get to zero i'll only have used 25kwh, rather than the reported 27.


A longer drive at the weekend of 60miles, had the car showing only 15% remaining when i arrived. Again an average of 3.2mi/kwh on the app and showing i'd used 20kwh which doesnt really tie up with the 15% remaining or the supposed 27kwh that is available. I should have flashed up LEAFSpy on that journey too but we were running a bit late and i didnt have time to fetch the dongle.
 
#20 ·
For my 58 miles daily commute, I can usually stay at around 20% remaining when I get home. Admittedly I drive slower on the motorway at 55-60 mph in the real world.

So to me, your ineffiiency doesn't add up. I had the impression you can work on 1 mile = 1% in the 30kWh Leaf.

Could it be the heater usage were not counted by Leafspy and Nissan app?
 
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