This is the 900bhp Jaguar C-X75 supercar, an £800k rival for the McLaren P1, Porsche 918 Spyder and LaFerrari – and we’ve driven it.
That’s the good news. The bad news is Jaguar actually cancelled the C-X75 project in December 2012, so the prototype we’ve driven doesn’t preview the production supercar, but instead tease us with what might have been…
How does the Jaguar C-X75 produce 900bhp?
The original C-X75 concept car (unveiled at the 2010 Paris motor show) used two diesel-driven micro-turbines to charge its batteries, which in turn powered four electric motors, one nestled in each wheel hub. Alas this potential powertrain proved a little too space-age, but Jaguar’s alternative solution isn’t exactly low-tech: there’s a supercharged /and/ turbocharged 1.6-litre engine using direct /and/ port-fed fuel injection, combined with two electric motors and a lithium-ion battery pack to create a four-wheel drive hybrid supercar with around 900bhp.
Should Jaguar have just slotted the 542bhp supercharged 5.0-litre V8 from the XFR-S into the C-X75, saved some weight, and saved itself a lot of technical headaches? That raucous V8 simply wouldn’t fit within the sleek silhouette, says C-X75 programme director Rob Atkin, and he and his team had four very specific objectives that precluded this Jag supercar from having a simple fossil fuel engine.
Those four objectives? For the C-X75 production car to have the same look and appeal of the original concept car; for it to achieve 0-100mph in same time as a Bugatti Veyron; for the CO2 emissions to match a Toyota Prius; and for the electric range to at least match that of the Chevrolet Volt. Quite a demanding list…
So for the Jaguar C-X75 to accelerate as hard as a Veyron it needed a 1.6-litre four-cylinder engine?
That, apparently, is right. The slender shape of the C-X75 means it can’t use some monstrous quad-turbo engine like the Veyron, and as even a V8 won’t fit Atkin and his team had to look for something smaller. Conversely, with the demands to be a clean and green as the Prius and Volt, the Jag needed a hefty set of batteries too.
Mix those two demands and you end up with a dry sumped, all-aluminium 1.6-litre four-cylinder nestled behind the driver, and flanked on either side by lithium-ion battery packs. The engine revs to 10,200rpm, is supercharged (for the low-rev response of a naturally aspirated engine) and turbocharged (for top-end power) and it has direct and indirect injection: at lower revs and under partial loads the two mix in and out to help the C-X75 be reasonably economical, but at high revs a second throttle body opens and both systems are used to throw as much fuel as possible into the engine.
Beyond that the engine is mated to a 295lb ft electric motor and a seven-speed automated manual transmission, and in the nose there’s another 295lb ft electric motor to drive the front wheels. The automated manual was developed because it’s small and light (much more so than a twin-cutch ‘box) but the transmission actually has two clutches, one to change gears with, and one to disengage the engine from the electric motor for EV running. Shifts take 200ms (the new 911 GT3 will shift in 100ms) but the nose-mounted electric motor sends some extra torque through the front wheels during the gearchange to compensate for the torque interruption to the rear wheels.
Anything else I need to know?
The C-X75 concept was aluminium, but the C-X75 production car is completely carbonfibre. Still, with all the batteries and motors aboard the kerbweight of the production car was predicted to only just sneak below 1700kg – that’s like-for-like better than the Porsche 918 Spyder, but a fair bit heftier than the P1 and LaFerrari. The five prototypes aren’t quite that lithe though, and the roll cage and testing and diagnostic equipment adds even more kilos.
But despite the switch from aluminium to carbon, the styling of the production C-X75 has changed very little. If anything, it’s actually improved, with the front grille now more akin to the F-type, fuller flanks, and a more aggressive rear diffuser. It’s gained door mirrors too, plus a pop-up rear spoiler-cum-airbrake, and the conventional doors of the concept have morphed into fancy flip-up dihedral items. The fifth prototype, painted dark blue, is particularly gorgeous.
How does the C-X75 drive?
In EV mode it feels about as brisk as a hot hatch – Jaguar reckons it’ll do 0-60mph in around six seconds – and there’s instantaneous urge from the electric motors. It’s not a silent experience either, as a ‘sound synthesiser’ produces a distant rumble of massive generators (like you’re on the bridge of the USS Enterprise and can hear the warp core deep with the bowels of the ship) and pulses a loud electric heartbeat when the C-X75 is plugged in and charging.
And the thorough road test? There are some caveats. The five prototypes were built to prove the technology, and the next stage was to develop the dynamic aspects of the C-X75. So although Atkin says 50% of the project was completed before it was cancelled, very little of that work was on any ride or handling set-up.
With just a few laps of Jaguar’s Gaydon test track allowed, what can we learn? That the electric power steering (the first application in a Jag, but the same system already on all the current range of Range Rovers) is light but not wholly devoid of feel, that the adaptive dampers (pinched from the F-type) give the C-X75 a reasonably compliant ride, and that the gearshifts aren’t as instantaneous as a double-clutch ‘box, but feel quicker than a Lamborghini Aventador yet also less brutal. Bar the lights and exhaust system, all the mechanical components are contained within the C-X75’s wheelbase, you do notice the weight through what corners and bends we can find. We suspect the Porsche 918 (with its rear-wheel steer system) and the McLaren P1 (with trick hydraulic suspension) will both feel more agile.
The engine is pretty special though. At idle there’s the rough chatter of the engine’s gear-driven cams, the shriek of the supercharger builds and builds until the point where it’s de-clutched at 5500rpm and it’s only the turbo forcing air through the engine, and then the deep snarl and growl of the exhausts really takes over and starts to deafen you. Despite the tiny engine, at 10,000rpm you’ll never think the C-X75 lacks any aural drama.
Is it as quick as a Veyron? Not quite. I’ve only driven the 1183bhp Vitesse, which is shockingly fast, but the Jaguar isn’t quite as brutally manic. But as we hit over 180mph on a relatively short straight there’s no doubting the power, and with the electrically assisted four-wheel drive the low-speed initial acceleration is particularly intense. Ditto those last few moments before you reach 10,000rpm in each gear.
LaFerrari. P1. 918 Spyder. C-X75. Despite the four representing a new breed of supercars, all are very different, and the Jag had the potential to have the most technically advanced hybrid powertrain – but it’s only one that’s been cancelled. And conversely, LaFerrari – with a relatively conventional 6.3-litre V12, no zero-emissions mode and a hybrid system designed purely to boost acceleration – is the only one of the quarter reported to have sold out. Is the worldwide market really ready for hybrid supercars?
Where does that leave the C-X75? The five prototypes will continue to be developed for the remainder of 2013, as technology contained within them is promised to filter through onto forthcoming Jaguars. The future is bright for Jag, but it would have been even brighter with a real halo supercar.