One statistic sums up why driving the VW XL1 hyper-economy car feels so special. It takes just 8bhp to push it along at a steady 60mph.
I got way beyond 100mpg on 75mph motorway plus some suburban running. And that was before I shut down the engine permanently and started draining the battery instead by switching to pure-electric mode. The XL1's light weight, low drag and minimised rolling resistance combine to make life as easy as possible for the powertrain, so it ekes out every bit of energy.
It looks like, and is made like, a dinky supercar. From the front there's a low nose and a narrow cabin that you drop into via clamshell doors. The mid-mounted engine has an electric boost motor. It's made almost entirely of carbon fibre, and you can read more about its amazing technology here.
Snuggling down into the lightweight but comfy carbon fibre seat, you have to turn over your shoulder to talk to your passenger, because they are staggered behind you. It's a way to get two people to nestle widthways into a cabin that's hardly wider than a sidecar. That keeps the frontal area down - and combined with a Cd of 0.19, this gives extraordinarily low overall drag.
It's a lightweight and simple cabin, but it manages to feel pricey and classy, even though there's none of the usual fancy VW gadgetry. The dash display is a simple Garmin-type effort that bundles together the sat nav, entertainment and hybrid readouts. The real novelty is the mirrors - there aren't any. Instead you have lipstick cameras, for drag reduction. They feed colour screens in the doors. Their picture is clear but it's not binocular, so you have to remember your distance perception is hampered.
The XL1 moves away by electric power. And - briefly - it strikes you as cheap and unrefined. The electric motor whines, and percussive road noise resonates through the carbon tub. Sound insulation is heavy, so the XL1 mostly does without. But under way, you seem to leave the noise behind you and things settle into a gentle buzz.
Is it quick? No. In electric mode (selectable by a button unless the battery is flat) you've only got 27bhp. Even in combined diesel and electric mode, it's a not-especially-dizzy 68bhp total. But it weighs less than 800kg, so that power is good for 0-62 in 12.7 sec, about the same as a base-model supermini. Pity it'll probably cost five times more.
But the driving is better than the supermini. It's agile and doesn't roll. There's no power steering so you have a terrific feel of the road. The ride's pretty good too, relatively pliant over sudden shocks, and well damped.
The little engine doesn't make a lot of noise, but there's a distinctive two-pot vibration when it's running. Like a Harley cruising past a very long distance away. But the engine actually runs for surprisingly little of the time - whenever you're off the accelerator, it's declutched and goes silent, while either momentum or the electric motor carry you forward. It restarts with nothing in the way of hesitation or clunks. The integration is seamless. And if, when running, it can easily develop more power than you need to drive along, it sends some energy back to the battery.
Because you make good progress on such little throttle, the hyper-miling game starts to become a very diverting occupation. You try to keep the engine off for as long as possible, and make sure you brake using the minimum pedal travel. That way you don't actually use the discs at all, but return all your energy to the battery as regeneration.
Driving the XL1 is a bit like being astride a top-end pushbike. You're always aware of its amazing efficiency and the wonderful precision of its engineering. Most of all, they combine to give you a palpable and deeply satisfying sense of getting along at the very minimum of effort.