How narrow is too narrow? Thinking in plan view.

[Rokeby]

There is an all-electric car that may be even narrower than the VW L1.
And it's not a concept, it's being driven on the roads right now, by some
very high profile people:



Here it is at an autocross:

http://www.youtube.com/watch?v=r0biS...ayer_embedded#

Read more here:
Commuter Cars - The Tango, ultra-narrow electric car; 0-60 in 4 seconds

[NeilBlanchard]

The Tango is ~2X taller than the VW, as well.

[aerohead]

Originally Posted by aspera

The VW L1 Concept shows to be 1200mm wide, 1143mm tall, and 3813mm long, Cd0.195. (VW 1L Prototype; 1250mm wide, 1 meter tall, 3470mm long, Cd 0.159)

I found these numbers for the Geo Metro.

Wheelbase 2,265 mm (89.2 in) (3-door/Conv.)
2,365 mm (93.1 in) (5-door/Sedan)
Length 3,745 mm (147 in) (3-door/Conv.)
3,845 mm (151.4 in) (5-door)
4,095 mm (161.2 in) (Sedan)
Width 1,575 mm (62.0 in) (3/5-door)
1,590 mm (62.6 in) (Sedan/Conv.)
Height 1,350 mm (53.1 in) (3-Door)
1,380 mm (54 in) (5-door/Sedan)
1,340 mm (52.8 in) (Conv.)

So, it ends up being about the same length as a Metro. The width is 15 inches narrower. Height is 8 inches lower.

I guess the only thing that really matter is how low the Cg (center of gravity) is on the Volkswagen. If they can get it low enough, the car is wide enough.

Aerohead, what kind of handling effects do you get with a low Cg? The L1 has lithium batteries in the nose...so the Cg should already be ahead of the Cp. But I'm curious about the vertical height of the Cg in relation to Cp.

Dr.Alberto Morelli of the Polytechnic Institute in Turin,Italy,who did the CNR series concept cars with Sergio Pininfarina doesn't think handling is a big deal now for low drag forms.
The low rounded fenders up front,parallel roofline/floorline and reflex-camber tail,with under slung strakes/fairings behind the rear wheels ( all of which VW is using on this car ) can make for a very stable platform as long as the CG is ahead of the CP,something easy to ascertain with today's modern tunnels.
The Ford Probe-V with Cd 0.137 had only a tiny dorsal fin at it's rear and it was probably more a place to locate the third brake light than for stability,and maybe to help the driver gauge the car's tail during backing maneuvers.

[aspera]

Originally Posted by RobertSmalls

For vehicles that do not lean during cornering, resistance to rolling over depends only on track width and the height of the center of mass. While the need to seat two abreast limits the width of most compact cars, it's the ratio of track width to CG height that limits the VW 1L and other tandems.



^^ That car needs a boat tail. Also note how they reduced ground clearance to lower the CG.

There are some unconventional approaches that might make for a better tandem car. You could have a faired, outrigger suspension like the Aptera's front, but detaching the wheels from the body raises your CdA, especially in a crosswind. Alternately, you could lean into corners like a bicycle or that new Nissan concept car.

I agree. What's the magic ratio? I bet the VW is better than lots of other vehicles on the road.

Besides, even if VW 'ruins' the production version of the L1 and makes the lower body a foot wider...it will still be the most efficient car on the road by a wide margin. Maybe *only* 100MPG.

[Frank Lee]

... a wide margin lol

[RobertSmalls]

Originally Posted by aspera

I agree. What's the magic ratio? I bet the VW is better than lots of other vehicles on the road.

Besides, even if VW 'ruins' the production version of the L1 and makes the lower body a foot wider...it will still be the most efficient car on the road by a wide margin. Maybe *only* 100MPG.

There is no magic ratio of track width to CG height. The minimum ratio depends on how stable you need the vehicle to be. All I can tell you is the Ford Explorer and Geo Tracker are too high and/or narrow, and the Lotus Elise is not.

Does anybody know the CG heights for the Tracker, Explorer, or any other topheavy SUV? Or perhaps what the threshold is for the "This is a rollover-prone vehicle" warning on the sun visors?

[robchalmers]

The L1 is a flag ship for the VW Group, and as such the I don't think roll overs will be an issue. after the whole debacle we saw with Merc putting the original Smart through the legendary 'ELK test' I think group will be keen to steer clear of similar problems.... get it!