One of the motors will also recoup energy while coasting, but there’s no regenerative effect triggered by pushing the brake pedal like on modern hybrids. It means that pedal works uncorrupted and actually feels fantastic: precise and performance-car firm. Surprising.
If that’s the only morsel of Prius that can be considered even vaguely sporting, the XL1 is quite different. In fact, it’s so inherently sports car ‘optimised’ that VW built a prototype with wider tracks, tyres that weren’t 115-section low-friction specials and the 187bhp V-Twin from a Ducati Panigale. That would have been good fun. As it is, the diesel-hybrid XL1, all 69bhp of it, is still in many ways deeply satisfying to drive.
The ride is robust but the damping fluent at speed, and the combination of double wishbones at the front and that natural steering makes the car an excellent communicator. It isn’t fast and, even with 25bhp of electric power to call on, throttle response is imprecise, but there’s something of the Lotus Elise about the way it moves. In contrast to the effortless way in which it goes down a road, the driver gets a bit of a workout.
The theoretical 313mpg economy potential comes at a price, though. The rigidity of the XL1’s monocoque and lack of soundproofing (the interior, with its wood-pulp dash, weighs just 80kg) means there’s copious road roar, even if the car slips through the air itself almost silently. The two-pot diesel – essentially an aluminium 1.6-litre TDI from the Polo halved – doesn’t transmit much vibration but has all the acoustic refinement of a marine two-stroker.
The wow factor of the rear-view cameras and their beer-mat displays also fades, leaving you with a car that has worse rearward visibility than the Lamborghini Aventador SVJ. The almost weightless gullwing doors are excellent theatre, but opening them up, vaulting the beautiful but broad carbonfibre sills and gently lowering yourself into the cramped cockpit becomes tiring. The need to carry around the suitcase-sized charger inverter robs the XL1 of what would otherwise be Porsche 911-beating boot space. Special? Hugely, but not exactly usable.
The Insight is more ordinary than the XL1. Perhaps unjustly, there’s just less pioneering spirit about the place, and this starts with the footprint. The Honda’s is neatly tapered to achieve an aerodynamic teardrop shape, but it’s subtle. On the XL1, the effect is so extreme that for a brief moment when Prior drives it over a crest behind me, I can see in the rearview mirror of the Insight clear daylight between the front and rear wheels on either side of the VW. It’s quite shocking.