Electric cars have smaller engines than internal combustion engines so they could theoretically be more turnable, of course this would reduce their trunk/baggage capacity, but a smaller turning diameter would be a very good argument for an electric for the city. Only hyundai or more its "Mobis mobility-tech" division developed a car that could turn in place. I understand that the materials would be more prone to wear and tear as if the cars were to look like this prototype, but why couldn't a more twistable front axle and a twistable rear axle be made in such a small urban electric, for example? (Not counting the fact that the floor plate would have required changes).
marek.0987754321
LEVC have a patent on the steering geometry of the London taxis, which allow them to turn really sharp.
London licenced taxis have as part of their requirements, have a minimum turn radius requirement.
That's why almost all licenced taxis in London are from the same manufacturer, and those that aren't are costly retrofits of existing designs, with complicated rear-wheel steering arrangements.
Rear-wheel drive, and lack of engine between the front wheels, makes it easier for tighter front wheel steering geometry to be achieved without fancy tricks, so electric vehicles like the Renault Twizy can get a nice small turning radius.
London licenced taxis have as part of their requirements, have a minimum turn radius requirement.
That's why almost all licenced taxis in London are from the same manufacturer, and those that aren't are costly retrofits of existing designs, with complicated rear-wheel steering arrangements.
Rear-wheel drive, and lack of engine between the front wheels, makes it easier for tighter front wheel steering geometry to be achieved without fancy tricks, so electric vehicles like the Renault Twizy can get a nice small turning radius.
Ahh is this why you were asking in your other thread about whether EVs have driveshafts?
They can of course, but it adds cost, complexity and weight. None of these are desirable in a low cost, city car. Smaller cars generally have perfectly acceptable turning circles, irrespective of the drive method. 'Specialist' vehicles like the London taxis quoted above operate to a different set of requirements. Again this was done before BEV drive with the diesel cabs and Vito derivatives.
What has the turn radius to do with the size of the engine or motor? It has to do with the size of the car and the way it's wheels are designed to turn, not the engine or the motor. The smaller the car, the easier to park (normally) but if you are a half decent driver you should not have problems parking a car, and even less, turning with it. Huge lorries or buses are one thing, those can have problems in tight turns, but come on, a personal car, even if it's large, except maybe the long extended limousines, have no problems getting around corners or parking. ...and the smaller they are the less need is there for turnable front AND rear wheels. It would just make them more expensive and extremely more complicated to make, so I think this idea is a dead end. I would also NOT like the idea that it needs to offer boot space. OK, if all cars had the ability to turn all their wheels by 90° then we would need much less parking space for parallel to road parking, but no other benefits, and also as long as not all cars have that feature, the space must be as it is today.
Many years ago I had a series of Honda Prelude's the last one (last model produced) had 4 wheel steering. This had the best turning circle of the 3 previous models. I know that because the house I lived in at the time had a difficult narrow entry to the drive and garage, the 4WS model got round in one manoeuvre against two or three previous cars. I don't know why this feature was dropped (maybe cost) Also the roadholding was brilliant down country lanes and up and down hills and mountains.
So what?
They have MUCH larger batteries!
I don't follow.
The steering geometry of the car is independent of what powers it.
The one 'small' improvement in turning operations from being an EV is only, and only if, the vehicle has in hub motors. By that technology all 4 wheels could (if design allowed, and if powered) rotate to, and beyond, 90 degrees, and the car simply moves sideways.
'thus';-
Tiny Car Changes Shape, Drives Sideways (EO 2) | Mashable News - YouTube
Out of interest, are you hoping for a commercial venture to patent something already known?
Quite the best turning vehicle I have driven was the UK Army Eager Beaver. The wheels themselves were fixed for straight ahead and the vehicle itself bent in the centre to go around corners using twin hydraulic rams to force the chassis central hinge pin to move as required. Weird seeing one of these deep inside a German forest as it could twirl around trees where normal lorries could not go. This picture is not on full lock yet.
Hardly a practical solution for a car though.
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Hardly a practical solution for a car though.
The ID3 turning circle is 70cm better than the current golf, so not a massive jump in a like for like example.
The ID.4 turning circle is 1.4 metres better than an Audi A4 though, which is quite significant.
I guess the a4 has to be packaged for a wide range of engines and drive trains so I’d imagine there are constraints preventing a good turning circle caused by the engine bay needing to accept twin turbo v6 + awd even if the base model is a wee baby 1.4 fwd.
The i4 has a turn radius of 12.5m which is 1.1m more than my current 330e has, but I guess I'll manage somehow.
Not really. There is some interaction. Keep reading for details.
Not at all.
Yes, but only in part. Clearance for the front wheels to turn, wheelbase and steering geometry have a lot to do with it. Of course that is assuming two wheel steering. Some American pickup trucks have rear wheel steering. I think Honda flirted with the idea too, but not to decrease the turning circle.
Front wheel drive sets a limit on how far the wheels can turn. The outboard CV joint can only articulate so far. Varies by car but they are all limited.
A front mouned engine or electric machine stack can also set an absolute limit. There needs to be clearance between the wheel wells and the motor for service. A big wide American V8 can get in the way.
The London Taxi has always had a turning circle no larger then 8.535 m (28 ft). There isn't any magic, at least not on the old ones. The tyres for the diesel taxi are 175/80 R16. The narrow tyres can turn further before they hit the inside of the wheel well. Taxis are rear wheel drive so there isn't an issue with CV joint limits.
BMW i3 turning circle is 9.9m 32.5ft. Again it is mostly the narrow tires combined with rear wheel drive. Mostly. No reduction in interior room. If anything the i3 has far more room inside than other cars of a similar size.
For comparison a Ford Focus turning circle is 11m(36ft). The Focus ST needs almost 40 ft. mostly due to the wider tyres.
@andrew*debbie Mercedes EQS is 5.2m long but has a turning circle of just 10.9m, that's just 1m more than the i3!
When I test drove it, the 10 degrees of rear wheel steering really does make it feel like a much smaller car on roundabouts and in car parks.
The Bond Minicar had wheels that turned 90 degrees. It didn't have a reverse gear, but didn't really need one for that reason and as it was so light you could easily push it.
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