Electric Cars:what's available?

This is the place for posts that don't fit into any other category.

Moderator: RichardW

Wookey
Donor 2019
Posts: 238
Joined: 28 Dec 2004, 09:43
x 6

Re: Electric Cars:what's available?

Post by Wookey »

Mandrake wrote:
03 Dec 2020, 11:48
Hyundai group are definitely one to watch over the next few years. They've already proved they can beat practically everyone else on efficiency using a shared ICE platform, (about 25% more efficient than nearly every other EV brand)
Has anyone worked out exactly what it is they did right to achieve this? It's not clear to me why everyone else is so much worse than Tesla and Hyundai. I'm not sure if it's actually just a little bit of everything: drag, heater, parasitic loads, cooling design, inverter design, tyres etc. (i.e. lots of `1%s' add up to 20% or so), or if there are a couple of components that are noticeably different.

User avatar
Mandrake
Posts: 8397
Joined: 10 Apr 2005, 17:23
x 401

Re: Electric Cars:what's available?

Post by Mandrake »

More on the Kona battery fire issue:

https://www.koreatimes.co.kr/www/tech/2 ... 04802.html
On the same day, the transport ministry said it had confirmed the risk of fire was due to an issue related to the way anode taps were used in the battery cells, which appears to have drawn out lithium residue from the cells. The ministry added, however, it has yet to replicate any of the reported fires.

The ministry said some battery cells manufactured at LGES' factory in Nanjing, China, between September 2017 and July 2019 were found to have defects and added this defect could lead to fires.

As the cause of the fires is not clearly identified, LGES has claimed that a structurally compromised anode tap in the battery cells could not be a direct cause for the fires, since the transport ministry couldn't replicate the case.
Still a bit of finger pointing going on... perhaps there is more than one contributing factor - cells with manufacturing defects being pushed a little too hard when charging for instance.

User avatar
NewcastleFalcon
Posts: 16160
Joined: 25 Feb 2009, 11:40
x 1640

Re: Electric Cars:what's available?

Post by NewcastleFalcon »

^^^ Bit of back story to the Hyundai/LG Chem (now LG Energy Solutions) intrigue.
viewtopic.php?p=677346#p677346


Over in China, NIO got a positive review from fully charged for their ES8 and their "white glove" customer service ethos. Definitely not producing a car for the masses, but the 4th biggest automaker in the world by Capital value, and currently investors backing the company and their vision.



Regards Neil

User avatar
Mandrake
Posts: 8397
Joined: 10 Apr 2005, 17:23
x 401

Re: Electric Cars:what's available?

Post by Mandrake »

Wookey wrote:
01 Mar 2021, 21:21
Mandrake wrote:
03 Dec 2020, 11:48
Hyundai group are definitely one to watch over the next few years. They've already proved they can beat practically everyone else on efficiency using a shared ICE platform, (about 25% more efficient than nearly every other EV brand)
Has anyone worked out exactly what it is they did right to achieve this? It's not clear to me why everyone else is so much worse than Tesla and Hyundai. I'm not sure if it's actually just a little bit of everything: drag, heater, parasitic loads, cooling design, inverter design, tyres etc. (i.e. lots of `1%s' add up to 20% or so), or if there are a couple of components that are noticeably different.
That's a great question, and without any direct experience with the (old) Ioniq/Kona/e-Niro I can't be sure, but I think it's a case of "all of the above".

Interestingly, Hyundai was ahead of Tesla for a while on efficiency - the original Model S with induction motors is actually not particularly efficient - it's better than average for a car that weighs 2200 - 2400Kg, and still a lot more efficient than the Audi e-Tron and Jaguar iPace for example, which came out years later and have really terrible efficiency. But the Ioniq beats the original Model S hands down for efficiency. But you kind of expect that when the Ioniq is a much smaller lighter (1420Kg vs 2300 Kg) car with far less performance. (0-60 something like 11 seconds)

It's not until the Model 3 came out that Tesla actually caught up to the efficiency of the Hyundai Ioniq in summer weather, and not until the 2021 model year of the Model 3 which added a heat pump that the Model 3 caught up to the Ioniq in winter efficiency. The Model 3 primarily made gains over the Model S by switching to a hybrid PMSR motor (permanent magnet switched reluctance) vs induction motors, using silicone carbide devices in the inverter, and also presumably reduced weight as it's around 400-500Kg lighter than the larger Model S. Both Ioniq and Model 3 have very good aerodynamics and this contributes to high speed efficiency which is an area where most EV's fall down.

Model 3 and original Ioniq are neck and neck for efficiency now - I think the model 3 has a slight edge >70mph but the Ioniq has an edge at slower speeds (city driving etc) and very cold conditions, especially vs the original no heat pump Model 3 which is still the majority of Model 3's on the road at the moment. But they're very comparable and streets ahead of all the other competition outside of Tesla and Hyundai/Kia group.

A fairer comparison that is a bit closer to home would be between the Ioniq, Leaf 30, and my Ion.

Driving to work in the summer (50/50 30mph residential and 50-60mph rush hour motorway) I used to get around 5 - 5.5 miles/kWh on my Ion without really trying - in the Leaf I only get 4.2 at most, with the heater off in the same conditions. Sure, the Leaf is a much bigger car and weighs 1535Kg vs 1140Kg for the Ion, but the Ioniq will do the same commute (based on extrapolating other people's results) and achieve around 5.5 miles/kWh - about the same as the much smaller Ion.

In winter I'm averaging around 3.2 miles/kWh (albeit with having the heater set to a comfy 22C) while an Ioniq will do 4 miles/kWh in winter with the heater on - about the same as what the Leaf does in summer with the heater off!

Where the Ion really fell apart was >60mph where its poor aerodynamics killed efficiency, (40% fall off in range between 50mph and 70mph) and in winter where draughts, poor insulation and lack of a heat pump murdered the efficiency - I was lucky to get 3.3 miles/kWh in winter with the heater set to the minimum to prevent me freezing and heated seats as well. So while the Ion could match the Ioniq at slow speeds in summer it was not even close in winter or at higher speeds.

So what contributing factors are there in the Ioniq to outperforming the Leaf so soundly ? Here's a few I can think of that probably contribute:

Better aerodynamics - the original style Leaf has a CD of 0.29 (0.28 for the facelift) while the Ioniq is 0.24 which is quite remarkable. The Tesla Model 3 is 0.23 so just a hair better than the Ioniq. This has a big effect on high speed efficiency and aerodynamics is the holy grail for achieving good high speed efficiency in an EV. The Peugeot Ion has a drag coefficient of 0.33... :lol:

Higher gearing - while I don't have the figures or know for sure I believe the Ioniq is significantly higher geared than the Leaf. The Leaf is 107hp, weights 1535Kg and yet the 120hp 1420Kg Ioniq is slower off the line. Why ? Probably due to being higher geared.

Why would you want to do this? High speed efficiency. With a standard permanent magnet AC motor the efficiency starts to fall off at high RPM due to effects that I won't try to explain here, this means if you gear the car too low this high RPM region where efficiency starts to fall will be within the cruise speed range (or at least the overtaking speed range) of the car. For example the Leaf's top speed of 92mph isn't that far away from the 70mph speed limit, and most people these days drive at 80mph certainly while passing and jockeying for position - this is close to the top speed of the car the motor efficiency will drop significantly, and that is on top of increased aerodynamic losses. The Ion was even more impacted by this as it is lower geared than the Leaf and tops out at 82mph so motorway cruise is only just below its maximum motor RPM where the motor really isn't working at its most efficient.

If you gear the car higher you drop the motor RPM and raise the top speed of the car - in fact the Ioniq's top speed is 102mph vs 92mph for the Leaf - another strong hint that it is higher geared. This pushes motorway cruise speeds to a lower motor RPM away from the region where the motor starts to lose efficiency so helps with motorway cruising efficiency. The trade off is it won't jump off the line quite as quickly unless the motor power was increased by a proportionate amount, so that initial surge isn't as strong but it holds it to a higher road speed before torque starts to taper off.

The Tesla Model 3 rear motor uses a fairly novel design called a Hybrid permanent magnet switched reluctance motor - this is a motor that can operate in two different modes. At slower speeds it can operate as a regular permanent magnet motor like the one in the Leaf which means high torque off the line, smooth lump free torque etc, but at higher speeds it can transition into switched reluctance mode which doesn't suffer from the efficiency loss and maximum RPM limit of a permanent magnet motor. This is explained quite well in the following video:



This allows the rear Model 3 motor to be both powerful, smooth and efficient at low rpm, and also be very efficient at high RPM, and dramatically raises the maximum RPM possible. (I think it operates up to around 18,000 rpm - most permanent magnet motor EV's only go up to about 8,000 to 10,000 rpm) This combined with Tesla's being higher geared than most "regular" EV's (to reach top speeds of around 130-155mph) means that the motor is operating very efficiently in that 70-100mph range where many EV's are not. The reduction in off the line torque due to higher gearing is simply made up for by increasing motor power - there is enough motor power that even with higher gearing it could spin the wheels from a standstill so you don't need any more torque than that!

The front motor on the Model 3 AWD is actually an induction motor but it is only really used for regen and foot to the floor acceleration - in cruise the front motor is put to sleep and just freewheels - which an induction motor is uniquely able to do even at very high speeds because without excitation it can't generate any voltage. (Whereas an unpowered permanent magnet motor freewheeling at high speed would be acting as a generator whether you want it to or not and generating high voltages at high speeds that the electronics need to deal with by applying field weakening)

It's possible the Ioniq uses some type of PMSR motor as well - I can't find any information to confirm the type of motor used, but it would certainly explain something if it did. Tesla are not the first to use it - I believe the BMW i3 uses a variant of the PMSR motor approach, although the physical design and layout is quite different to the Model 3 motor, so they are both different riffs on the same general principle.

Ok what else could help an Ioniq to be more efficient than a Leaf at lower speeds - one thing for sure is regen. The Leaf has relatively weak accelerator lift off regen. It has two drive modes - D and B. D has hardly any regen on lift off and B has what I'd call moderate regen. In fact the lift off regen on the Leaf is quite a bit weaker than my Ion was - and I already thought the regen on that was weak! As the regen is so weak I drive in B mode nearly all the time.

On the Ion the first inch or more of brake pedal travel increased regen smoothly but didn't apply any friction braking until most of the regen was used up then it would blend friction brakes in quite nicely as you pressed further. That meant that even if you did use the brake pedal if you slowed gently it was all regen and no friction brake until you pushed further.

You do get more regen on the Leaf when you start to press the brake pedal - up to about 30kW, but it seems to bring the friction brake in at the same time instead of progressing from one to the other. This causes both a somewhat abrupt braking action (which takes a bit of getting used to) and means that you can't really tap into the maximum regen without simultaneously applying friction brakes. A combination of weak maximum regen and inability to access all of what you do have without also using the friction brakes will really hurt overall efficiency as regen can increase range by as much as 25% in slow speed driving.

The Ioniq has three levels of lift off regen controlled by flappy paddles - if you want to you can set it to be very strong so you can get strong regen without touching the brake pedal and therefore be sure friction braking isn't involved. This is especially useful if you were trying to go slowly down a steep hill for example as regen is effectively your engine braking equivalent. The Leaf's regen isn't strong enough to hold it back to 30mph down a steep hill so you end up wasting some energy in the friction brakes.

Conversely in smoothly flowing motorway driving there can be some efficiency gains in reducing lift off regen so you don't accidentally decelerate when lifting your foot a bit - the Ioniq's flappy paddles let you customise the level of regen to the driving conditions so you can have it strong when you want it or weak (or off!) when you don't.

Another issue the Leaf has with regen is you get zero regen between about 95-100% charge and don't really get full regen until you're down to 90%. So the first 10 miles of driving or so from a full charge you're relying mostly on friction brakes so that can cause up to a 25% loss in driving efficiency for those first 10 miles if you charge to 100% - and the Leaf doesn't give you a way to charge to less than 100% unless you monitor the charging and manually unplug it.

While the Ion gave reduced regen at 100% charge it did still have a buffer that allowed a significant amount of regen even then. While I haven't driven an Ioniq I believe that it also allows a significant amount of regen at 100% charge, and furthermore has a charge limit option where you could just tell it to charge to less than 100%. You might want to do this if you lived at the top of a hill for example so you have full regen available right out of the gate. So I definitely think the Leaf doesn't take full advantage of regen and the Ioniq almost certainly does.

How about cold weather performance? Cold weather is of course where EV's struggle the most with range loss. There are two main culprits here - energy expenditure to heat the cabin and reduced efficiency and usable capacity of a cold battery.

The Ion was badly insulated, had draughts, (especially around the feet) had no heat pump, and the PTC heater it did have heated a water loop to heat a traditional heater matrix - which is both very slow to warm up and very inefficient, gobbling up about 5kW to get the car adequately warm below freezing and still averaging around 3kW once warm. In short the Ion was atrocious in winter with a barely adequate heater that reduced range 40% or more. Heated seat covers and warm clothes were a must. It felt a bit like a conservatory on wheels in winter - heater blasting hot air but still cold. :lol:

The Leaf is a big step up in the heating and winter driving department. There are zero draughts and the car is unusually well insulated - all the doors have a full layer of thick carpet underfelt behind the door cards for example which are absent on my Xantia. Carpets are much thicker than the Ion as are the doors. It also has heated seats and steering wheel.

It has both a PTC heater (a direct air heating element, not a water loop heater) and a heat pump - a seemingly little known fact among EV drivers is that all EV's with heat pumps still have PTC heaters as well - because there are certain conditions where heat pumps aren't very efficient or can't operate at all, for example if the evaporator freezes up - which has actually happened to me twice this winter in -8C thick fog weather where I presume the fog condensed on the evaporator and eventually blocked the fins... in that case you need a PTC heater to take over, albeit less efficiently. I was still nice and warm when this happened - the only real clue something was up was that the heat pump was noisier than normal, (eg audible instead of inaudible) the radiator fan was going at high speed, and then they both suddenly stopped and stayed off for the rest of the journey, with heater power consumption going up as the PTC took over.

In typical conditions between around -5C and 15C a heat pump can use up to 3x less power than a PTC heater, however they can't produce very high temperature air for defrosting and also are a bit slow to warm up. So in the Leaf at least when you first turn the heater on it runs the heat pump and PTC heater together - in mild weather about 500 watts for the heat pump and maybe 2kW for the PTC heater during the initial first few minutes warm up. Then as the demand for heat drops it dials the PTC heater back until it eventually (usually) goes off completely leaving only the heat pump to maintain the cabin temperature.

It was 2C this morning and the average heater power consumption settled down to around 500 watts - in the Ion in the same conditions it would have been around 2.5kW...

So it works pretty well but in my observations the PTC heater runs a lot more than it probably should, and I get the impression that the heat pump is a bit small and underspec'ed on the Leaf - physically it's actually quite a bit smaller than the A/C compressor on the Ion was and runs at a significantly higher RPM. I think the Leaf really could have done with a bigger heat pump and that it uses the PTC heater as a crutch more than it should. Again, I have no direct experience of the Ioniq but from what I've read I think the heat pump is a bit more capable in the Ioniq so it relies less on the PTC heater.

The other winter factor is battery temperature. Lithium Ion batteries don't like being below freezing. Not only can you only charge them very slowly when they're that cold (much slower rapid charging speeds) it also increases their internal resistance causing increased I^2R losses under high acceleration/regen scenarios (although the heat generated does actually help warm the battery, which is a positive side effect) eating into your efficiency.

Not technically an efficiency reduction, but the useable capacity of a Lithium Ion battery also reduces significantly in the cold - basically you can't discharge them as low when they're cold as when they're warm, so some capacity at the bottom effectively becomes unavailable until it warms up again. This is because the voltage will sag lower under load when the battery is cold than warm, so to avoid subjecting the cells to excessively low voltage either the load has to be reduced or a higher ceiling on minimum SoC has to be enforced.

The Leaf as is well known does not have any battery thermal management - at least in the UK market. It has no active heating and no active cooling. The Ioniq has both a forced air cooling system and a battery heater. In very cold weather it can precondition the battery while plugged in - essentially warming up the battery before departure (as well as the cabin) so that it's at a more efficient temperature. The Leaf doesn't have this in the UK market so if you have a very cold battery after the car has sat all weekend in -8C tough luck - the efficiency will be lower and usable capacity will be reduced so you'll see a very significant range hit due to the cold battery.

In Canada and Scandinavia the Leaf does actually come with a battery heater - if it didn't the battery would get so cold in -20C and lower that it would become impossible to charge it and efficiency would fall through the floor. However in the UK market Nissan don't deem the battery heater as worthwhile so it doesn't get one here.

The Ioniq having a battery heater as standard potentially makes quite a big difference to sub zero performance even in the UK. Likewise all Tesla's have active battery thermal management that can both cool and heat the battery as needed. In extremely cold conditions where the battery is too cold to charge it will actually warm the battery first and then begin charging automatically.

Anyway that's a few thoughts on efficiency of Tesla vs Hyundai vs Leaf! I'm sure there are other tricks the Ioniq uses, presumably parasitic loads are also kept low, efficient inverters etc... but whatever their secret sauce is, more of that please! :)

User avatar
NewcastleFalcon
Posts: 16160
Joined: 25 Feb 2009, 11:40
x 1640

Re: Electric Cars:what's available?

Post by NewcastleFalcon »

Lets look at the end of the market that will bring about the biggest change. We have had a little delve, but this little product is the biggest selling ev in China.

It busts the myth that a city ev has to start at £20,000 and they are churning them out in the biggest ev market by far in the world for well under £5,000. Joint venture with that old dinosaur GM. GM may have a winner on their hands but will they do anything with it :?:

So in the vid they mention...no airbags. Its spec would need raising for the European Market, but not raising to justify a doubling in price. Rumours that a partnership with a Latvia Auto Company is set to bring it to Europe are mentioned in the video.



Regards Neil

Gibbo2286
Donor 2020
Posts: 5188
Joined: 08 Jun 2011, 18:04
x 1105

Re: Electric Cars:what's available?

Post by Gibbo2286 »

A nice looking lady but a bit more of the car and a bit, a lot, less of her face and chatter would make the video much more watchable. :roll:

User avatar
Mandrake
Posts: 8397
Joined: 10 Apr 2005, 17:23
x 401

Re: Electric Cars:what's available?

Post by Mandrake »

The problem with some of these little EV's in China Neil is that they're basically just tiny egg boxes on wheels designed for slow driving in crowded cities only. Aside from a lack of air bags I highly doubt a car of this size and price would get an adequate ncap rating in the European market or would be safe to drive at 70mph on the motorway in the event of an accident. If you have a head on collision with a range rover in one of these you are not going to survive. :shock:

I often complain about how heavy and bloated modern cars are compared to those in the 90's and earlier, but there is one thing that is undeniable - modern "bloated" cars are by and large incredibly safer in the event of a crash and not just due to air bags.

Just compare my Xantia with my Leaf when it comes to crash worthiness. The Xantia is 1496Kg, the Leaf is 1535Kg. They're both the same length and width down to a couple of cm, similar interior space, but my god is there a difference in the ncap performance.

1.5 stars for the Xantia vs 5 stars for the Leaf. If I have a major accident in the Xantia at speed I've got a good chance of serious injury despite two air bags. The A pillars and roof in a Xantia just crumple up like a tin can, and the pedals and steering wheel intrude significantly. The ncap video is pretty terrifying to be honest. Contrast that to the Leaf which not only has side and curtain airbags, but has a HSS (high strength steel) passenger compartment, reinforced doors and A-pillars and a better designed crumple zone at the front. The passenger cell in the Leaf is completely intact in the ncap frontal impact test.

The Ion/i-Miev actually does get a 4 star rating, so is theoretically safer than the Xantia in a crash, but that's a bigger car than the Mini EV in this video and also makes extensive use of HSS in the passenger cell and has full side and curtain airbags as well. In its day it was an expensive car for the size.

At the price they're selling these Mini EV's at there's no way I can see them using more expensive HSS, we already know they don't have airbags, and there's only so much you can do to reinforce and make a tiny car safe as a tiny car by definition doesn't have much crumple zone to work with.

Imagine trying to take a car the exact same size and shape as the classic mini from the 60's and redesign it to have a 5 star safety rating without making it any bigger - it just can't be done in a car that small, and the same applies here.

I think it's cool that China are going so gung ho with EV's, and I can see a use for small, cheap city cars in massive overcrowded cities they have in places in China, but I just can't see a car this small as being viable in the European market where it will also have to deal with motorways, fast A roads etc... I wouldn't feel safe driving one even if they added basic airbags. We've come so far with safety in the last 20 years, lets not go backwards.

For reference, Xantia and Leaf ncap tests:




Gibbo2286
Donor 2020
Posts: 5188
Joined: 08 Jun 2011, 18:04
x 1105

Re: Electric Cars:what's available?

Post by Gibbo2286 »

How does the Mercedes small car (Smart) do in the ncap tests Simon?

User avatar
Mandrake
Posts: 8397
Joined: 10 Apr 2005, 17:23
x 401

Re: Electric Cars:what's available?

Post by Mandrake »

Gibbo2286 wrote:
03 Mar 2021, 11:02
How does the Mercedes small car (Smart) do in the ncap tests Simon?
Pretty well actually:



I highly doubt the Mini EV will be built to the same standards though...

Something to keep in mind is these tests are into a solid barrier. In the case of a head on collision with another car or collision with a parked car (which will move when you hit it, reducing the impact force) the smaller you are relative to the car you hit the more rapid the deceleration you will experience.

If I drove my Ion into an oncoming range rover vs driving my heavier/larger Leaf into one I'd be a lot worse off even if they did equally well on a fixed barrier crash test like ncap due to conservation of momentum.

No matter how safe the car is made for its size and how good the ncap rating is, being small puts you at a disadvantage when you crash into larger heavier cars.

Hell Razor5543
Donor 2021
Posts: 11664
Joined: 01 Apr 2012, 09:47
x 1394

Re: Electric Cars:what's available?

Post by Hell Razor5543 »

Fifth Gear crashed a Smart Car at 70MPH into a twenty tonne concrete barrier (set at an angle). The results will surprise you, as there was minimal intrusion into the safety cell. However, the G forces involved would almost certainly have killed the occupants.


User avatar
NewcastleFalcon
Posts: 16160
Joined: 25 Feb 2009, 11:40
x 1640

Re: Electric Cars:what's available?

Post by NewcastleFalcon »

I had a look around for any bang up to date information on the Dacia Spring. Not much, back to October 2020 for this from the Dacia horses mouth.

Wonder if Renault are choking back its wider launch.....I sort of think so with their targeting of the Dacia Spring for car sharing for shared urban mobility, and a cargo utility vehicle. They do of course need to shift Twingos and Zoes.

This is the latest press release from Dacia on the Spring I can find.
https://press.dacia.co.uk/en-gb/releases/280
Dacia is now writing a new chapter in its history with the unveiling of its first all-electric model. The Dacia Spring Electric concept car was first shown in March 2020, marking Dacia’s arrival on the electric city car market.

Now, Dacia has revealed the full production version of the Spring Electric, however it will not be available in the UK. Two new options will be available in continental Europe for use across different mobility reasons: a version for car-sharing for shared electric urban mobility, and a cargo utility vehicle, for last-mile deliveries with no tailpipe emissions.

The Spring is a revolution: as the lowest-priced electric city car on the European market, it makes electric mobility even more accessible. With its disruptive SUV design, it boasts a spacious cabin, a simple and reliable electric engine and a reassuring driving range. It is a versatile and practical city car.
In moving pictures


Regards Neil

Gibbo2286
Donor 2020
Posts: 5188
Joined: 08 Jun 2011, 18:04
x 1105

Re: Electric Cars:what's available?

Post by Gibbo2286 »

So it's not a question of size, size doesn't mean it can't be done, the Chinese EV car built by Mercedes standards might be a winner for a lot less money than the Smart.

User avatar
mickthemaverick
Donor 2019
Posts: 6653
Joined: 11 May 2019, 17:56
x 1867

Re: Electric Cars:what's available?

Post by mickthemaverick »

Mandrake wrote:
03 Mar 2021, 10:51
The problem with some of these little EV's in China Neil is that they're basically just tiny egg boxes on wheels designed for slow driving in crowded cities only. Aside from a lack of air bags I highly doubt a car of this size and price would get an adequate ncap rating in the European market or would be safe to drive at 70mph on the motorway in the event of an accident. If you have a head on collision with a range rover in one of these you are not going to survive. :shock:
[Edited]
I think it's cool that China are going so gung ho with EV's, and I can see a use for small, cheap city cars in massive overcrowded cities they have in places in China, but I just can't see a car this small as being viable in the European market where it will also have to deal with motorways, fast A roads etc... I wouldn't feel safe driving one even if they added basic airbags. We've come so far with safety in the last 20 years, lets not go backwards.
Whilst I fully agree with your final sentence here Simon I do believe the foregoing sentences suggest you may be missing the point of this car. While you suggest that a 70mph crash with a Range Rover is going to be dangerous, the fact is it is not going to happen. Stated quite clearly in the video the car has a top speed of 62mph!! :-D

However, more seriously I think your summation that there is no place for such a car in Europe is wildly off the mark. Given that you are fortunate to live in the UK's prettiest country I think you may be unaware of how problematic traffic issues have become in our large cities. I have a mate who lives in Islington North London and works in Hammersmith. Given that he does not like the issues you face with public transport in London late at night, he commutes by road. Without doubt the fastest way of doing that in London is on his push bike as he does not trust motorcycles. However that is only really doable during fair weather as not only the cold but the slippery roads make it hazardous in the wet. The simple cost of using his car, a Volvo 440, to travel within the ULEZ and even the old congestion zone, which he lives just outside of, make a small electric enclosed vehicle a very viable proposition for him.
After all we had hundreds of small electric vehicles on our roads in the 50's, 60's and 70's built to do a job. They were called milk floats!! So this car will definitely appeal to a large number of city workers who will appreciate the opportunity to travel around their city in comfort and privacy without polluting the environment and very seldom exceeding 25mph let alone 62!! :)

Hell Razor5543
Donor 2021
Posts: 11664
Joined: 01 Apr 2012, 09:47
x 1394

Re: Electric Cars:what's available?

Post by Hell Razor5543 »

If the EV is travelling at 30MPH, and the Range Rover hits it head on at 40MPH you then have a combined speed of 70MPH.

User avatar
Mandrake
Posts: 8397
Joined: 10 Apr 2005, 17:23
x 401

Re: Electric Cars:what's available?

Post by Mandrake »

Hell Razor5543 wrote:
03 Mar 2021, 13:22
If the EV is travelling at 30MPH, and the Range Rover hits it head on at 40MPH you then have a combined speed of 70MPH.
Makes intuitive sense but it doesn't work like that. :)

Lets use a simpler example. Say you have two equally sized cars of the same model that weigh the same and are both travelling 30mph who collide head on, so they are closing towards each other at 60mph.

Is that the same as one car crashing into a solid wall at 30mph or at 60mph? It's actually the same as crashing into a solid wall at 30mph, not 60mph, even though the combined speed is 60mph...

You have to think about the deceleration of the individual vehicles and the centre of mass of the two vehicles once they come into contact.

In the two equal cars at equal speeds case as soon as the cars make contact their combined centre of mass remains stationary at the impact point and the deceleration of each car (and resulting crumpling/damage) is equivalent to the two cars individually hitting a solid wall - in other words if you put a solid wall between them and they both hit it together from opposite sides the result would be the same in terms of g-force and damage because they are still slowing with the same g-force.

If one car is lighter than the other then it will experience more g-force and more damage because it will actually end up going backwards instead of the two coming to rest at the impact spot. Meanwhile the heavier car will experience less g-force hitting a smaller car than hitting an equal size car.

Unfortunately physics dictates if a heavy car hits a light car it's the lighter one that will suffer more! (All else being equal)