VW XL1 production version gallery

[NeilBlanchard]

Wyatt, you may be right; but the XL1 is at least 0.06 lower Cd than the Insight; which is almost 25% lower. They both have tapered sides and narrower rear wheel tracks, and covered rear wheels, and similar smooth front wheels. The side video mirrors and the underside of the XL1 are the obvious big differences. And they weigh close to the same - the VW is slightly lighter, including the 5.5kWh lithium battery.

So, VW's engineers have worked very hard to find the big penalties, I'm sure.

[wyatt]

Originally Posted by NeilBlanchard

Wyatt, you may be right; but the XL1 is at least 0.06 lower Cd than the Insight; which is almost 25% lower. They both have tapered sides and narrower rear wheel tracks, and covered rear wheels, and similar smooth front wheels. The side video mirrors and the underside of the XL1 are the obvious big differences. And they weigh close to the same - the VW is slightly lighter, including the 5.5kWh lithium battery.

So, VW's engineers have worked very hard to find the big penalties, I'm sure.

Absolutely.

[botsapper]

Originally Posted by Old Tele man

...aside from the useless door side-panel sculpting, I like it.

...the original concept vid shows that side panel sculpting as an actively controlled intake vent.

http://www.youtube.com/watch?v=nMg-CoA4gak

[wdb]

Originally Posted by Old Tele man

...aside from the useless door side-panel sculpting, I like it.

Originally Posted by wyatt

It would have been nice if they would have rounded the wheel wells like on the Gen1 Insight. According to this picture, it would have improved the Cd by about 0.007 (probably a little less), or take it from 0.189 to around 0.182. Not insignificant when there are so few improvements left to be had.
I agree with Old Tele Man, that sculpting should go. The hubcaps should have been made as smooth as possible also.
I guess these may have been things they traded, and the improvements were so small that they decided to keep the styling. I guess we may never know.

I'm always amused when people assume they know better than a phalanx of engineers with millions of euros, several years of research and development, and a windtunnel.

[Blue Angel]

Originally Posted by wyatt

It would have been nice if they would have rounded the wheel wells like on the Gen1 Insight. According to this picture, it would have improved the Cd by about 0.007 (probably a little less), or take it from 0.189 to around 0.182. Not insignificant when there are so few improvements left to be had.

The aerodynamic gains available by such a mod will vary vehicle to vehicle, and will also be totally dependant on the airflow leading into that area. It is quite possible that VW has set up the front end to direct airflow outward off the nose so that it doesn't contact the side of the car again until after the front wheel well opening.

I would imagine this is why GM added small deflectors (not sure what they're actually called) to the front of the front wheel well openings on the C6 Z06 (and later kept them on the ZR1)... even though the car already has generously sculpted edges on the rear of the front wheel wells. These would keep air from hitting the tires and getting forced into the wheel well, but may also keep air from hitting the wheel face and rear edge of the wheel well.

You can see the deflectors very clearly on both sides in this photo:

Chevrolet Corvette C6 Z06 Exotic Car Image #010 of 44 : Diesel Station

[wyatt]

Originally Posted by Blue Angel

I would imagine this is why GM added small deflectors (not sure what they're actually called) to the front of the front wheel well openings on the C6 Z06 (and later kept them on the ZR1)...

I have always heard them being called Fender Flares, or something very similar.

I am sure the real answer they didn't do as Old Tele Man and I suggested is for marketing/styling purposes. Super cars have air intakes running along their doors, either to cool their mid-mounted engine, or to cool rear brakes. I have seen no evidence of an active system on this car, but they did have it on the first two prototypes. I see Ford Mustangs every day with fake rear intakes, so to me it's not surprising that it was kept, seeing as how it adds dimension and a "supercar feel" to the vehicle.

[wyatt]

Originally Posted by wdb

I'm always amused when people assume they know better than a phalanx of engineers with millions of euros, several years of research and development, and a windtunnel.

It's not the first time someone has been amused with me in this thread.

Those millions of euros are evidence that Volkswagon understands what sells, and are not evidence that they max out their machines for aerodynamics. I am not saying, and do not mean to imply, that VW made the wrong decision.

[some_other_dave]

Originally Posted by wyatt

I have always heard them being called Fender Flares, or something very similar.

Fender flares would be extensions to widen the fender, not deflectors in front of the wheels. At least, that's the usage that I am familiar with for that term.

-soD

[gone-ot]

Originally Posted by botsapper

...the original concept vid shows that side panel sculpting as an actively controlled intake vent.

...unfortunately, it looks like that feature did not make it into the current model, ie: they're now just for looks and, well, "useless" vestiges.

Originally Posted by wdb

I'm always amused when people assume they know better than a phalanx of engineers with millions of euros, several years of research and development, and a windtunnel.

...nah, I'm just just observant. What they were for "originally" doesn't count now, since they're only for show and not for go now!

[NeilBlanchard]

Here's a very informative animated video of the VW XL1:

http://www.youtube.com/watch?v=YL8qD...ature=youtu.be

In particular, the frontal area is 1.50 sq m which is 16.146 sq ft. The Cd is 0.189, so the CdA is just 3.05 sq ft. The EV1 is 3.96 sq ft.

Notice the location of the battery pack - it is tucked into the space just ahead of the passenger, which is staggered back from the driver.