I’ve driven my fair share of efficiency optimised vehicles and while some of them have certainly been impressive, it is a near-universal truth that they’ve not entirely lived up to the economy claims by their makers… when driven normally. Sure, the claimed economy figures are generally achievable, but only when driving with the hell-bent purpose to achieve them.
Volkswagen claims a combined cycle fuel consumption figure of 0,9 litres/100 km for its efficiency obsessed XL1, and I’m happy to admit that I didn’t believe it would be achievable on my 50 km test run in Wolfsburg, designed to give me a feel for the car’s various modes and features, and with both of the car’s seats occupied. And yet, I completed the run with a consumption figure of 0,7 litres/100 km!
Admittedly, it was cool enough outside for me to leave the air-conditioning deactivated, but except for that, I drove as I normally would, accelerating from stops with purpose, cruising on the highway at over 100 km/h and certainly not being content with being a mobile chicane. It is a mighty impressive achievement.
Why does it exist?
The XL1 may well be claimed to be the world’s most efficient production car, but the reality is that Volkswagen only plans to build 250 and sell them (in Europe) to extremely wealthy VIP customers. You may therefore understandably point out that the XL1 is a bit pointless to the man in the street. Well, not exactly. The XL1 previews a number of technologies that will become available in mass-produced Volkswagens (and VW group vehicles) sooner rather than later. For example, the company will introduce its first plug-in hybrid to the market next year (a petrol/electric Golf), and the group is currently working to homologate various of the XL1’s amazing features for world markets, including its groundbreaking rear-view camera “side mirrors” and polycarbonate windscreen. What will not become mainstream very soon is its use of a carbon-fibre reinforced polymer (CFRP) for its construction – it remains too expensive, and Volkswagen believes there are still many ways to achieve weight reduction using existing and cheaper materials. But for VW group brands such as Lamborghini, Bentley, Bugatti and Porsche, carbon fibre will certainly become more commonplace.
The XL1, then, is an amazing technology showcase. But it’s one that’s being produced and which is, to some, commercially available.
Obsessive efficiency
The XL1 was in effect born at the dawn of the new millennium when Dr Ferdinand Piech (chairman of the VW supervisory board) stated his desire for a car that would use less than 1,0 litre/100 km. And as if the goal of sub 1,0-litre/100 km consumption wasn’t difficult enough, Piech also wanted the car to be practical enough for daily use. No wonder it took the engineers so long… To fulfill Piech’s dream, the focus (in the extreme) was on weight saving, aerodynamics and a significant electric-mode range.
The XL1 weighs only 795 kg through its extensive use of carbon fibre (even the anti-roll bars are of CFRP). Only 184 kg of the total weight comes from steel or iron parts. Besides its lightweight and small size the XL1 complies with all safety requirements.
It really is very small. Unlike the earlier two concepts, the XL1 doesn’t feature tandem seating. It does, however, feature a staggered seating arrangement – the passenger sits slightly back from the driver. This allowed Volkswagen to design a significantly narrower car than would otherwise be the case. At 3 888 mm long, 1 665 mm wide and 1 153 mm tall, the XL1 is shorter and narrower than a Polo, but also lower than a Porsche Boxster! The two-seat cabin is, however, spacious, with good head- and legroom. There’s also a small luggage compartment behind the rear-mounted engine.
In terms of aerodynamics the XL1 sets a new benchmark with a Cd figure of 0,189. Besides its teardrop shape, you’ll also notice the covered rear wheels and the lack of side mirrors. Mounted in the doors are rear-facing cameras that send a feed to high-resolution screens mounted in the doors on the inside. Amazing stuff…
Powertrain
By comparison with its body construction and packaging, the drivetrain actually seems quite “normal”. The XL1 uses a plug-in hybrid system consisting of a two-cylinder turbodiesel engine that delivers 35 kW, a 20 kW electric motor, seven-speed dual-clutch transmission and a lithium-ion battery of 5,5 kWh. The diesel engine is essentially half of the 1,6-litre unit you find in a normal Polo TDI. Drive goes to the rear wheels.
Volkswagen claims a 0-100 km/h time of 12,7 seconds – though sub 11-second acceleration is possible according to the engineers. Top speed is limited to 160 km/h, but without the electronic restriction the XL1 would run to over 200 km/h. Far more important than the performance figures is the amazing claim of 0,9 litres/100 km and, consequently, 21 g/km CO2 emissions. For interest’s sake, the XL1’s fuel tank takes 10 litres.
On the road
In the metal… or rather, the fibre, the XL1 is a very small car that looks like it has arrived from the set of a sci-fi movie. The butterfly doors add to the visual impact of the vehicle, of course. Inside, once you’ve stopped marveling at the screens in the doors that double as rear-view mirrors, the rest of the controls are fairly familiar. There’s a normal gearshift lever, traditional analogue instrumentation and the Garmin infotainment system from the Up!
We started our drive in EV mode, with power only being drawn from the batteries. As is to be expected, it is eerily quiet in this mode, yet feels sprightly off the mark. It can be driven for up to 50 km in pure electric mode, enough for 80 per cent of daily trips in Europe. To recharge the battery from a normal household power outlet takes less than two hours.
The steering feels very direct and quite weighty, and the engineer in the passenger seat pointed out that it is purely mechanical and unassisted. Why not electrical assistance? Well, the mechanical system is lighter. For me, however, there’s an added benefit. I don’t like overly light and artificial steering. The meatiness and directness of the XL1’s steering make it feel very sporty on the road and well matched to the car’s similarly firm ride quality.
One quickly gets used to driving the XL1 – Piech’s desire for a usable car has certainly been fulfilled – and it has quite surprising sprinting capabilities when needed. But there is one problem… When the turbodiesel engine engages, the noise in the cabin is extremely intrusive and it sends vibrations through the car’s structure. Again, it is down to the focus on weight saving – there is precious little sound insulation in the car – but it is somewhat jarring in an otherwise superbly refined and high-tech car. Volkswagen is, apparently, looking at ways of limiting the sound intrusion without adding too much weight.
Besides the noisiness, the only other problem I have with the car is the fact that, due to its low roof, I couldn’t see traffic lights overhead! Oh, and the ceramic brakes are also quite noisy.
In summary
The XL1 is certainly a groundbreaking car. And it is the product of a very confident company that can afford to give its engineers free reign on projects that won’t necessarily add to its profitability. The engineers working on the various aspects of the XL1 (from new materials, to electronics and aerodynamics) have since been redeployed to more mainstream projects, and the lessons learned on this amazing car will undoubtedly be applied to future mass-produced machines. Success, as they say, breeds success.
Specifications:
Model: Volkswagen XL1
Engine: 0,8-litre two-cylinder turbodiesel, E-motor
Power: 35 kW (TDI) + 20 kW (electric)
Transmission: 7-speed DSG
0-100 km/h: 12,7 seconds
Fuel consumption: 0,9 l/100 km
CO2: 21 g/km
Top speed: 160 km/h
Price: unavailable in SA
All manufacturer-claimed figures
