Volkswagen AG is planning to roll out a production car that will combine a plug-in hybrid powertrain with low weight and aerodynamic shape to reportedly achieve a startling fuel efficiency rating of 261 miles per gallon (mpg).
Although the mileage numbers will almost certainly drop when a US EPA rating is applied, the XL1, as it’s known, will likely be the most fuel efficient production car in the world. Today‘s best vehicles -- the Honda Fit EV, Scion IQ EV, Mitsubishi i-MiEV, and Ford Focus Electric, among others -- typically have mpg-equivalencies that are less than half that of the proposed VW.
”This vehicle combines every possible way of improving fuel efficiency,” Volkswagen spokesman Mark Gillies told Design News. “It uses aerodynamics, low-rolling resistance, low weight, and a plug-in hybrid powertrain.”
Click on the image below to get an up-close look at the XL1.
The XL1 follows sports car design principles -- low weight, low drag, and a low center of gravity. Its winged doors are made from carbon fiber-reinforced plastic. (Source: Volkswagen AG)
Indeed, in the years of development work that went into the new VW XL1, the company’s engineers incorporated virtually every available fuel efficiency feature. The new vehicle supplies just enough power to make itself road-worthy, while incorporating enough low-mass components to keep its energy needs low. A 47-HP turbo-diesel engine, for example, sips fuel, while a 27-HP electric motor gives it a enough pop to hit a top speed of 99 mph.
The key to its road-worthiness is its low weight. At 1,753 pounds, it’s less than half of the Chevy Volt’s 3,781 pounds, thanks to liberal use of lightweight materials. Approximately 20 percent of the vehicle employs carbon fiber-reinforced plastic, including the monocoque, body panels, anti-roll bars, and numerous other parts. The brakes also use carbon fiber ceramics, while the engine crankcase, steering gear housing, dampers, and other suspension components are made from aluminum. Even the XL1’s windows were designed with weight reduction in mind, all of them being made from polycarbonate.
VW’s new vehicle may also offer the lowest drag coefficient in production car history. At 0.189, it’s lower than the Toyota Prius (0.25), Tesla Model S (0.24), Mercedes-Benz CLA-Class (0.23), and General Motors’ EV1 (0.195). It accomplishes that with a tadpole-like shape that’s wider at the front than the rear.
Narrow tires also help, as do fairings and air vortex generators that prevent airstreams from getting caught around the wheel housings. Side mirrors are gone, as well -- the XL1 will use cameras instead. Finally, the vehicle is so thin (1,665 mm) that it calls for the seats to be offset. ”We couldn’t put the seats side by side,” Gillies told us, “so we did it by putting one of them slightly behind the other.”
The real test of the vehicle’s efficiency, however, may lie in its all-electric performance. Using a 5.5-kWh water-cooled, lithium-ion battery, the XL1 can travel 32 all-electric miles, meaning it gets close to six miles to the kilowatt-hour. That’s almost twice that of the Volt or Leaf.
All of the fuel efficiency ratings will be up for debate, of course, as the vehicle’s limited rollout nears. The XL1’s 261-mpg figures are based on European Commission methodology, which calls for the vehicle to travel 100 km, using its all-electric mode, followed by a diesel fuel mode.
US EPA test cycles, however, are notoriously tougher. General Motors notably proclaimed a 230-mpg efficiency for the Volt and Nissan said its Leaf would get 367 mpg in 2009, before EPA test cycles put both vehicles closer to 100 mpg-e when they were launched in 2010.
Volkswagen isn’t talking price yet, but is saying that production will be light and will start soon. The German automaker is already retooling a plant in Osnabruch, Germany, to build the XL1 in “a limited production run.” Unofficially, VW officials have talked about manufacturing only 250 vehicles, but the number could climb into the low thousands. ”What we can say is that it’s going to be in peoples’ hands fairly soon,” Gillies told us.
Thos gull wing doors are put there because a door has to hinge on something and if you can get rid of the bending moment delivered by a hard-top door a lot of things get much lighter. That is the reason, which is that there is no way to make a stiff enough "A-Post" to support the door. So gull wing doors are an easy out to handle the problem of how to support the doors. Yes, they do look cool but I find thm very inconvenient.
Gull wing doors are a cliche' that designers use to make an automobile look really mod and futuristic. I doubt they have any aerodynamic advantage, and the disadvantage is what happens if you open a forward facing one while rolling. The forward facing but normally hinged "suicide doors" used on some pre-WWII cars were banned for compelling safety reasons. Just don't open the doors a highway speed, you say? Ah, but people do for all sorts of reasons e.g. to free a seatbelt or reseat a partially latched door.
This sounds like a great car if you live where the land is flat and the climate is perfect. Using the tricks mentioned, you can go fast with a low power to weight ratio on a flat road, but I'd like to know what happens to speed going uphill. Sure, the peak capability of electric drive can zip you over a neighborhood hill on your way to the Piggly-Wiggly, but there are mountain passes in Colorado, Calikfornia, Utah, and elswehere that require pushing hard for miles at high alititude. The resulting load will exceed the thermal time constant of the electric drive. What then? There is also the effect on mileage when a heater or air conditioner is running. Those aren't optional in Michigan or Arizona.
And those tires... Early autos used narrow tires. They require high air pressure to be stiff enough to carry weight up on the smaller footprint. This makes for a bumpy ride and reduced ability to handle mud and snow. That's why they disappeared.
There aren't really any tricks - get the road weight, cross section, drag coeeficient and tire heating down, and Bob's your uncle. Simple things like the precision of fit-up of body panels and under-body skins make a difference. Electric motors have a high intermittent stall torque and horsepower relative to continous ratings which allows them to pack a lot of performance into a low continuous horsepower rating. Well deployed hybrid technology allows the combustion engine to work into sweet spots. As you point out, no magic is needed.
The 1,753 pound weight is 40 pounds more than the 1,713 pound weight of the '84 Honda CRX HF that I used to have. That car didn't have any carbon fiber or anything more exotic than aluminum for the engine bllock and transmission case. Of course, it didin't have any airbags either but we haven't heard whether the new VW meets those American requirements. Likely not. BTW, the Honda was rated at 50 mpg highway, a figure that was achieved by many owners. No tricks, just a well engineered light car that met American regulations of the era.
If you google freedomev and hit image the black vehicle that pops up is my all composite body/chassis stronger than steel but only 235lbs.
A very old wiki freedomev I think is somewhat good now. It had been hacked by chinese though have no idea why as rhey did it in chinese!!
Once my 2wh EV Streamiliner is presentable and a few products in the next 6 months, I'll come out with a serious website but not smart to do if no product yet now. I could do a website now but wouldn't have any time left because of all the questions and have too much work still to do.
So much hype. If it's so eff then why does it need more energy that a 3000lb EV-1 of which the lead version only used 175wthrs/mile or the GM Impact, it's prptotype they should have built at 100wthrs/mile?
It's grown from 1000lbs IIRC to now the 1700+lb unit yet their MPG claim doesn't change!!
As far as weight my all composite body/chassis weighs far less that the VW does and not an once of CF. There is no reason it should weigh over 1200lbs and should be under 1000lbs.
Anyone want to bet this never gets produced? So I'd certainly call it a paper car. Sad as we need this class but done right.
Tesla Motors plans to roll out a “compelling, affordable electric car” that will sell for about half the price of its high-profile Model S by the end of 2016, company chairman Elon Musk said last week.
From Dell / Intel® New Paradigms in Design Work Scott Hamilton, vertical market strategist for Dell Precision workstations, 5/2/2013 5
Early in my career, I worked as a draftsman and remember the days of drawing on vellum with numbered pencils and Mylar with plastic lead. This was a fun experience in the sense that I ...
I've been using workstations for more than 10 years and love finding ways to get more performance from my system. With demanding professional applications that require more power each ...
A lasting memory from my first job as an engineer in an auto assembly plant is standing on hard concrete at six in the morning, vending-machine coffee clutched in hand, listening to ...
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This radio show will show what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.
To save this item to your list of favorite Design News content so you can find it later in your Profile page, click the "Save It" button next to the item.
If you found this interesting or useful, please use the links to the services below to share it with other readers. You will need a free account with each service to share an item via that service.
Tweet This
40 
