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Discussion Starter · #1 · (Edited)
I understand EV-specific platforms provide a boost to production for manufacturers, but what do they provide for the end-user beside "a larger cabin", or eventually, lowering the prices?

I have driven cars using the same platform for ICE and BEV, and exclusive BEV, and to be honest, haven't found a noticeable difference.
 

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2018 Nissan Leaf 40kWh Tekna - love it
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I did recall the transmission tunnel is very annoying in Jags, the XF, XE and F pace. The iPace doesn't have it, just a small ridge.
 

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I have driven cars using the same platform for ICE and BEV, and exclusive BEV, and to be honest, haven't found a noticeable difference.
Theoretically they can better optimise the suspension for the lower CoG of an EV, but unless you spend time throwing the car around that's not of much interest to most people. So, yeah, not much difference from the daily driver PoV.

'Transmission tunnels' are still common as they provide a channel for services to the other end of the car and help structural rigidity. A truly flat rear floor will have costs, and if it's only a few cms most people aren't that bothered by it. (There'll always be one, but that's life. 80:20 rules :) )
 

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Bigger batteries, as the battery can be one unit it can be cover a larger area of the floor pan. Designed from the floor up it's possible to get closer to a 50-50 weight distribution.

A dedicated EV platform also means the suspension is optimised for the weight of the EV. There's the potential for a front storage. With no need to leave space for a rear silencer that space can also be used for storage.

Don't forget the ICE versions of cars are also compromised, the design has to make space for batteries, wiring etc. The brakes on an EV probably need to be a bit bigger for the higher weight. Making more variants of a model pushes up costs, complicating production lines.
 

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KIA Soul EV 64kWh
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I understand EV-specific platforms provide a boost to production for manufacturers, but what do they provide for the end-user beside "a larger cabin", or eventually, lowering the prices?

I have driven cars using the same platform for ICE and BEV, and exclusive BEV, and to be honest, haven't found a noticeable difference.
A common platform optimises inventory, manufacturing, packing etc.
This reduces cost and could in theory translate to lower selling price.
The benefits are to the manufacturer but mean faster product development which means more cars to choose from.
It is the job of marketing to provide customer benefits!
 

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Making more variants of a model pushes up costs, complicating production lines.
Whilst true, it's also several orders of magnitude cheaper to run a single production line than 2. The Hyundai/Kia cars no doubt take great advantage of having BEV and ICE on the same production lines.
 

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The larger cabin element shouldn't be breezed past too quickly though, it makes a significant difference. You only need to look at an ID.3 to see how much more of the space they were able to give to the cabin, as the bonnet is tiny on it.

I have an ID.3, but am currently driving a Golf Mk 8 courtesy car due to my ID.3 being bricked by a software update (fingers crossed my dealer bring it back to life, but VW's software trials and tribulations is a matter for another thread). They are about the same dimensions externally, but the ID.3 feels significantly more spacious inside. When you sit in the two of them back to back, you really do realise how significant that space difference is.
 

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Although due to familiarity its not been done yet in the mainstream, the bespoke EV platform gives the option of drastically different car design from the traditional styles that are a legacy of ICE requirements.

Canoo have an interesting new design. Well I say new, but its actually very reminiscent of the 1950's to 1970's VW Bus.
 

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Bigger batteries, as the battery can be one unit it can be cover a larger area of the floor pan. Designed from the floor up it's possible to get closer to a 50-50 weight distribution.

A dedicated EV platform also means the suspension is optimised for the weight of the EV. There's the potential for a front storage. With no need to leave space for a rear silencer that space can also be used for storage.

Don't forget the ICE versions of cars are also compromised, the design has to make space for batteries, wiring etc. The brakes on an EV probably need to be a bit bigger for the higher weight. Making more variants of a model pushes up costs, complicating production lines.
A dedicated EV platform allows the OEM to take cost out of manufacturing which will benefit the consumer. Compare ID3 with Corsa for how this plays out.
 

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Looking at the design of dedicated EV platform cars versus converted ICE platform cars it does look as if the dedicated EV platform cars usually managed to have a longer wheelbase within the available length. That seems to make for more internal room and allows the driving position to be moved closer to the front of the car although there must be a limit as to how far this can go because of the need to provide adequate crashworthiness and long enough crumple zones.

I don't think that any manufacturer including Tesla has yet managed to break away from making electric cars look very much like ICE cars even though they could look very different with the freedom to reposition things that the much smaller drive train should give. I watched a video a week or so ago showing a chap making a kit car using a Tesla drive train and was surprised at just how small and modular it looked not much larger than the suspension and rear axle assembly for a conventional car and yet it was the whole drive system in one unit.

There must be loads of scope for making integrated electrical heating and cooling systems that are more compact than conventional car systems too as they still seem to look like the sort of multiple component systems that conventional cars have. My neighbour fitted a small heating and cooling airconditioner in her conservatory last year and that is an impressively well integrated bit of kit and it must be pretty efficient as she finds it cheap to run.

Perhaps car making is like the building industry and just very slow to pick up on new ideas and ways of thinking. All my career I came across building trades that refused to do things better because they were just stuck in the rut of having always done things one way and they were never going to change. The regulations here are now changing that as it is pretty difficult to build a house in the crappy way they were thrown up 20 years ago during the boom and so builders are being forced to use new methods but some of them don't much like it all the same.
 

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A few other things that haven't been mentioned so far in this thread, or expanding on them....

Weight

An EV dedicated platform is lighter as an EV than an ICE-compatible platform as an EV. For example, the Tesla model 3 LR is over 300kg lighter than the Polestar 2 (very similar size, performance, battery size, ie a fair comparison) largely because of the platform optimisation. The model 3 SR+ weighs in at 1611kg, which is over 100kg less than a Leaf 62 and 200kg less than an e-Niro.

Lower weight improves efficiency.

Aerodynamics

An EV platform will tend to have a flat under-body, whereas an ICE-based model will often have voids in the underside where various bits of exhaust or engine venting was required. Smoother underbody is more aerodyamic.

An EV-dedicated design can also have a much lower front end (eg Model 3) and again better aerodynamically. Even though an ICE-derived EV may have a blanked off grille, it is overall a less aerodynamically optimised shape than a dedicated EV model.

Better aerodynamics improves efficiency.

Suspension design

Designing around a big ICE engine brings compromises of where the front suspension is located, but more significantly how much space it may take up. Transverse engine installations take up a lot of room, which means that suspension may be designed for compactness (eg macpherson strut) rather than ride/handling performance.

It can also limit wheel articulation (as anyone that has ever driven a volvo with a transverse in-line 5 or in-line 6 can attest). Removing those limitations on the suspension can give space for higher-performing suspension designs or greater wheel articulation (and hence the excellent turning circles of models like the Honda e and the VW ID3).

Crash structures

The principle of designing a car for crash safety is how you deal with energy absorbtion and keep your passengers safe. Typically this is done by having a very strong structure (the passenger "cell") that absorbs no energy, remaining rigid and intact, and surrounding it with structures that can absorb some energy (crumple zones).

The problem with an ICE is that it's not really very crumply - the engine is a significant problem in crash design. Not having an engine makes it possible to design better front-end crash structures, as well as more pedestrian-friendly (no solid engine to smack your head on) without resorting to expensive measures like pyrotechnic pop-up bonnets (the cost of deployment of such a system can easily write-off a £50k+ car in a very low-speed incident).

Benefit to consumers

Safer, better handling, tighter turning, more efficient vehicles.
 

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A dedicated EV platform allows the OEM to take cost out of manufacturing which will benefit the consumer. Compare ID3 with Corsa for how this plays out.
Exactly. And to position the drivetrain where they wish - hence the ID3 is rear wheel drive with the benefits of a decent size frunk and considerably more internal space for its overall length. Anything sharing a platform with an ICE is limited to the positions of the ICE for the drivetrain and the larger space for the ICE restricts the internal room available. A good comparison here is the i3 and the Mini-e which are from the same stable (BMW) and have some components in common, yet the space in the i3 is considerably larger.
 

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Kia e-Niro 4 MY20
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It gets really interesting when you start questioning design even more, e.g. the corner concept from the Israeli firm I can’t remember the name of.... I’m not sure we’re all quite ready for steering by wire, but the point being a lot of car design is based around mechanical necessities, many of which go away.
 
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