Miles/kWh

[rogerco]

Found this. For mpg read range.

In principle I think for an EV, since the motor is equally efficient throughout it's range, the dominant factors are rolling resistance (tyres on tarmac) which is proportional to speed and dominates at low speeds and wind resistance (drag) which is roughly proportional to square of speed so comes to dominate at higher speeds.

Plus, as I found out yesterday, things like having the heater on and other electrics (lights etc) have a larger effect than with an ICE which can heat the cabin with waste heat from the engine and is running the alternator all the time so the increasing load on that is merely an addition to the base load from simply turning it without any draw on the 12v system.

I guess there might be an after-market opportunity to fit a woodburning stove in the back for winter use

 

[Petriix]

Had a bad one yesterday:
View attachment 3129
This was on the way back from S.Glous to Cornwall via a stop in N.Bristol to recharge. Thought we'd have comfortably enough to get home, but what with rain, so wipers and lights on, cold so windows steaming up without the A/C so had to have that on most of the time at 17deg, and probably a headwind of 20-40mph we travelled a mere 6 miles for every 10 miles the GOM dropped. Had to stop for an emergency charge at Exeter as not enough range, even on the GOM, to get near home
Thank goodness the Exeter Services Ecotricity CCS was working yesterday (it often isn't apparently) as public CCS points are a bit few beyond Exeter.
Speed on m5/a30 was 60-70mph apart from a section at 50mph on cruise for 6 miles through the roadworks

The outward trip on Sunday was done at 3.9 miles/kWh.

Not looking forward to doing long trips in the winter - but at least we know now - or is something wrong?

The significant factors are the headwind and the rain. It takes a lot of energy just to displace the water on the road, and a 20mph headwind can use 15% more energy. Wipers and lights use such a tiny amount of energy in comparison as to be negligible.

 

[rogerco]

Ah yes, of course, the rain increases the rolling resistance, and probably quite significantly. Thanks for pointing that out. Its not the wipers that kill it!

I wonder if driving slowly in wind and rain would bring the range back up - I guess it would. Next time I'll try driving down the motorway at 40-50mph and arrive in the same time without having had to stop for a charge!

 

[Jocko]

Because of the "Square Law", a headwind makes much more of a difference to drag than the same wind from behind assists. Rain makes a huge difference, especially if the roads are awash. A tyre will displace 30 litres a second at 50 mph. It takes a lot of energy to shift 430,000 litres of water on an hours drive.

 

[Johnny 5 is alive]

Always nice to see the 100 miles come up with 60% remaining on a road trip
Loving the range on these cars!

 

[rogerco]

Following our difficult drive back from Bristol in the rain last Monday, on Friday we got this much better sight.

In fact a few miles later it was up to 5.2m/kWh for 30miles, then came the climb up to the top of Dartmoor which knocked it back to 4.4 for 35 miles.
(yes the photo was taken by the passenger whilst driving, hence the funny angle)

 

[GavinJ]

It's amazing how much difference ambient temp makes (and free-ish moving town traffic). No "special measures" econ mode and Kers3 (sorry for blurred photo - obviously too excited to break 5 kwh barrier )

 

[Petriix]

I never seem to break the 5 barrier, probably because most of my local journeys are under 10 miles and it seems to build up the longer you drive for. I did only use 4% to do my 10 miles of running around this afternoon but it only reported 4 miles per kWh, having started at 3.2 and slowly crept up as I drove.

 

[Kithmo]

I never seem to break the 5 barrier, probably because most of my local journeys are under 10 miles and it seems to build up the longer you drive for. I did only use 4% to do my 10 miles of running around this afternoon but it only reported 4 miles per kWh, having started at 3.2 and slowly crept up as I drove.

My ZS rarely gets more than 3.2-3.4 m/kWh because like you I only do short journeys, normally 3 miles each way with a break in between. Today I managed a whopping 4.6 m/kWh going to the dealers for some touch up paint, 9 miles each way. That equates to 195 miles range with the ZS having 42.5 kWh usable battery capacity.

 

[Mark Holmes]

My ZS rarely gets more than 3.2-3.4 m/kWh because like you I only do short journeys, normally 3 miles each way with a break in between. Today I managed a whopping 4.6 m/kWh going to the dealers for some touch up paint, 9 miles each way. That equates to 195 miles range with the ZS having 42.5 kWh usable battery capacity.

Good isn’t it....

 

[Valiant5]

I'm doing quite a few journeys across the Peak District at the moment, volunteering with the National Park and meeting up with family. A few weeks ago my 5 achieved 5.9 miles/kWh on a journey home from the Staffordshire Moorlands, admittedly with a 700ft descent over 25 miles. On Sunday the car best even that returning the 23 miles home from near Buxton... incredibly, 6.3! A similar rate of descent, and 7 per cent of the battery used.

 

[Mark Holmes]

I'm doing quite a few journeys across the Peak District at the moment, volunteering with the National Park and meeting up with family. A few weeks ago my 5 achieved 5.9 miles/kWh on a journey home from the Staffordshire Moorlands, admittedly with a 700ft descent over 25 miles. On Sunday the car best even that returning the 23 miles home from near Buxton... incredibly, 6.3!View attachment 3212

Wow stuff of dreams that’s massive.....

 

[Johnny 5 is alive]

Round trip to Newcastle and back gave me 120 miles on the first 50%, it would be nice to think this would equate to a 240-mile overall range but I'm not sure I'd want to run it that low again
However it bodes well for our holiday in Troon next week, checking out the charging points, it's a whole new way of life!

 

[Stuwit46]

I have the longest journey today since getting the 5 it’s exactly a 200 mile round trip, 200 was one of the main reasons I bought it. I fully intend to NOT use a charger, but will drive to the speed limit (in normal mode) where I can and use the air con on auto. One thing going for me is the temperature. The route is around 80% 70mph limit 20% other. Will it do it? What do you think?

 

[Cocijo]

It would be great if you can. Personally i doubt it. My own experience at higher speeds is it is exceptional if you get 200miles. My 75kwh tesla struggles to do it at 70mph. Good luck!

 

[jamesie]

Approx 4 miles/kWh @ mostly 70mph....hmmmm!

Good luck, hope you do it (but have a bail out plan!).

 

[Jake]

I have the longest journey today since getting the 5 it’s exactly a 200 mile round trip, 200 was one of the main reasons I bought it. I fully intend to NOT use a charger, but will drive to the speed limit (in normal mode) where I can and use the air con on auto. One thing going for me is the temperature. The route is around 80% 70mph limit 20% other. Will it do it? What do you think?

At least you are returning home to a 100% guaranteed charge point so that eliminates charger anxiety. By monitoring your m/kWh usage you could always adapt your driving later in the journey if necessary to squeeze the last drops but why? Is it a challenge? Will you be stopping for a break in 200 miles (I know I would have to my bladder would be shouting) and if so that's an ideal opportunity for a splash'n'dash.

As you say the weather is on your side so if you know your driving style will achieve ~ 4m/kWh then on paper you should manage it. I reckon you are in it for the thrill and excitement plus achievement factor rather than the relaxed trip it could be.

Good luck and we look forward to hearing all about the trip later.

PS my 4+ m/kWh T shirt has just been delivered by the postman so maybe that's a good omen.

 

[Les burrows]

I have the longest journey today since getting the 5 it’s exactly a 200 mile round trip, 200 was one of the main reasons I bought it. I fully intend to NOT use a charger, but will drive to the speed limit (in normal mode) where I can and use the air con on auto. One thing going for me is the temperature. The route is around 80% 70mph limit 20% other. Will it do it? What do you think?

Hi Stuart waiting for the update not sure looking at the 70mph for what about 160 miles in N mode maybe in E but good luck and safe journey
Les

 

[Mark Holmes]

I have the longest journey today since getting the 5 it’s exactly a 200 mile round trip, 200 was one of the main reasons I bought it. I fully intend to NOT use a charger, but will drive to the speed limit (in normal mode) where I can and use the air con on auto. One thing going for me is the temperature. The route is around 80% 70mph limit 20% other. Will it do it? What do you think?

Yes you will easily do it if the route is fairly flat…

 

[Kithmo]

Hi Stuart waiting for the update not sure looking at the 70mph for what about 160 miles in N mode maybe in E but good luck and safe journey
Les

The GOM may say yes in ECO but it's driving style that dictates whether it's possible or not, regardless of what mode it's in.
FWIW the WTLP figures are quoted in Normal mode.