261 mpg Volkswagen XL1

The Volkswagen XL1 Concept’s efficiency is already legendary: in windless conditions it needs just 8bhp to maintain a steady 62mph and it can return up to 313mpg. And yet if you were to deploy all available power it would hit 125mph, although for now it’s governed at 100mph.
 




We were in Qatar. This small emirate is reputed to have a per-capita GDP that ranks among the highest in the world. It has energy to spare, with plenty of oil and the world’s third-largest reserves of natural gas. The population produces three times as much carbon dioxide per person as does that of the United States. Premium gas costs the equivalent of just a dollar per gallon—and that’s after a recent 25-percent increase in the government-subsidized price, which caused serious consternation among the country’s V-8–packing drivers.
This VW is presumably the first European auto to have its Earth acquaintances preceded by much appreciation to Allah. Soon after its introduction at the first-ever Qatar automobile expo, the Xl1 was inspected by Sheikh Hamad Bin Jassim Bin Jabr Al-Thani, the nation's PM and minister of foreign affairs and a part of Qatar's ruling family. His wife enjoyed it and was accounted for as saying that she might want to have one. Most different guests were bemused by the work up about a bit two-seater with a small motor and turned their considerable consideration towards the Touareg Gold Edition stand, a practice in 24-karat overabundance exceptionally made for the wealthy audiences.

 
The XL1 is Volkswagen’s latest “1-liter” car. This term doesn’t refer to engine displacement but rather to the European method of expressing consumption, which is to say the amount of fuel needed to travel 100 kilometers. Traveling that distance on one liter of fuel translates to 235 mpg—or, put differently, New York to Boston on one measly gallon of diesel. A 1-liter car would simply be the world’s most efficient combustion-engined passenger vehicle, and VW says the XL1 actually needs just 0.9 liter to travel 100 kilometers, which means the claimed maximum efficiency is a heady 261 mpg. 

 

The 1-liter car was Ferdinand Piëch’s idea, and he drove the first concept, a cigar-shaped tandem two-seater, to the 2002 board meeting at which he retired as CEO. The intervening years produced a “2-liter” prototype that was only shown internally, as well as the L1 that appeared at the 2009 Frankfurt show. The XL1’s hybrid system consists of a 47-hp, 800-cc two-cylinder TDI turbo-diesel engine, a 27-hp (20-kW) electric motor, and VW’s seven-speed DSG dual-clutch gearbox. (The DSG is programmed to operate only in automatic mode.) The TDI and the electric motor combine to deliver maximum torque of 103 lb-ft. This amazingly compact powertrain is mounted transversely behind the passenger compartment and drives the rear wheels. A 5-kWh lithium-ion battery pack and a 2.6-gallon diesel fuel tank are nestled between the powertrain and passenger compartment.
The major factor in weight saving was the use of carbon fiber for the chassis and body panels. The center monocoque/safety cell is molded in one piece by a rapid resin-transfer process that’s quicker and cheaper than conventional hand-laid carbon. VW developed it with the Austrian company Carbo Tech, which also helped implement a similar system for the McLaren MP4-12C supercar. The XL1’s supersmooth, aerodynamically optimized shape should achieve an extremely low drag coefficient of 0.19. 

 

Program manager Steven Volckaert noted the project has been underway for more than a decade, with the original goal of squeezing out 100 kilometers from a single liter of fuel. For the metrically challenged, that works out to about 235 mpg.
VW revealed its first attempt in 2009, a tandem-seating concept dubbed the L1. With a somewhat more traditional interior layout-and even better mileage, the XL1 made its world debut at the Geneva Motor Show last February 2013. So the XL1 looks racy, but its ultimate performance is leisurely: 0 to 60 mph takes about 11.5 seconds, and top speed is limited to 99 mph. 


Considering the elaborate and expensive weight-saving measures, the XL1 is heavier than one might expect, at 1800 or so pounds. Its predecessor, the L1, came in at a claimed 840 pounds. Blame the twofold increase on the safety equipment and the comfort and convenience features required to turn a vehicle solely focused on efficiency into an acceptable everyday car. The VW XL1 is primarily made out of CFRP, or carbon fiber-reinforced plastic, the same exotic material used in Formula One race cars and the most extreme sports cars like the Volkswagen Group's Lamborghini Veneno. There are other light materials such as magnesium wheels and ceramic brakes, and clever engineering reduced the parts count so only half the normal front cross-member is needed.
A variety of wind-cheating tricks also play a role, including full underbody panels and instead of conventional side-view mirrors, the XL1 uses a pair of tiny cameras that display images on LCD screens built into each door. 

 
But the heart of this high-mileage beast is that minuscule 2-cylinder, 0.8-liter (that’s 800cc) 48-horsepower diesel engine paired with a 27-hp electric motor drawing power from a 5.5 kilowatt-hour lithium-ion battery.
Even though it ditches earlier versions’ tandem seating, the XL1 remains narrow and tapers at the rear, so the passenger seat isn’t aligned with the driver’s; it’s offset toward the stern by a few inches to preserve shoulder room. As with other vehicles that can operate purely on electricity, everything is remarkably quiet at step-off and at low speeds—all you hear is the thrum of tires on asphalt. Once you press harder on the accelerator to demand more power, the diesel engine starts, without any jolt but with a curious tinny rattle. Lift the pedal, and the gentle calm returns as the engine stops instantly; it restarts in milliseconds when you flex your right foot again.
You can, however, force the car to run only on electricity. Select that mode, and the TDI diesel is declutched from the drive wheels, at which point the XL1 can run for a claimed 22 miles and reach a top speed of 50 mph. Recharging the batteries via a plug takes an hour and a few cents. But the XL1 won’t leave you stranded. Like the Chevrolet Volt’s gasoline engine, the VW’s diesel powerplant takes over when the batteries reach a minimum charge level. 






 


 It requires a spot of exertion to slip in under the gullwing entryways and afterward wedge oneself into the low-threw seat of the Volkswagen (Xetra:vow3-DE) Xl1. Furthermore its significantly more challenging for a traveler, as the traveler seat is situated marginally rearward, very nearly pair style. The straightforward actuality is that the windswept two-seater isn't constructed for solace. The Volkswagen Xl1 was intended for greatest mileage. Digging in into the carbon-strand driver's seat feels uncommon, and you're faced by a little steering wheel squared off at the bottom and a decently provided and delightfully trimmed dashboard. The Xl1 has no back window or side mirrors; set up of the recent, movie Polaroids nourish two little screens in the inward entryway boards. Design-wise, the inner part is instantly unmistakable as a VW. Spectators, seeing the entryways pivot upward as we moved on board, inquired as to whether it were a baby Lamborghini.
Our drive suggested that the XL1 would be a rather lumpy ride. Blame the narrow Michelinlow-rolling-resistance tires, which run at a firm 45 psi. But the XL1 steers accurately and easily, without the need for power assistance. Given a relative lack of suspension travel because the car is so low, it absorbs road irregularities well, although you have to watch for ruts and speed bumps.
The brakes are fitted with lightweight carbon-ceramic discs and offer excellent stopping power, the pedal’s feel odd, as it’s as unassisted as the steering, a rarity in modern vehicles. 

 
You’d need many miles behind the wheel or finely calibrated equipment to verify the official fuel-economy figure, which was calculated by the European authorities using a new drive cycle for plug-in hybrids. The number reported was a bit better than VW expected, at the equivalent of 261 mpg. So here is a car, primarily driven by a diesel engine, with minimal emissions (24 g/km of CO2 versus, say, thePrius’s 89 g/km) that can claim to be more efficient than more highly vaunted pure-electric vehicles.
For now, the XL1 is still a prototype. But VW Group chairman Martin Winterkorn promised it will be available by 2013 “at an affordable price” guess that will be somewhere around the equivalent of $50,000, this is just the thing European eco-warriors have been waiting for. We can only hope that VW planners opt to sacrifice a few pounds and a couple mpg when the two-seater goes into production to make it more comfortable. Even if it "only" delivered 255 mpg in final trim would potential buyers be disappointed? Unlikely.