Jaguar has a V6 diesel-engined version of its XK sports car in development.
The company has tested the car at the Nürburgring, where Autocar’s spy photographers heard the engine’s diesel rattle.
The Jaguar XK D is powered by the new 272bhp twin-turbo 3.0-litre V6 that’s due to be launched in the XF this spring.
Despite putting the engine through its paces on the track, Jaguar has chosen to monitor sales of the new 5.0-litre V8-powered XK before deciding whether to put the XK D into production.
A decision is now unlikely before the end of 2009, so the XK D wouldn't go on sale until at least 2011.
Jaguar is concerned that the XK D might scavenge sales from the naturally aspirated 5.0-litre V8 XK, on which it can make a greater profit.
A sales analysis of the BMW 6-series supports these worries. Sales of the twin-turbo 635d have displaced those of the 630i and 650i.
A Jaguar XK D would be a potent tool. Powered by the highest-output version of Jaguar’s new twin-turbodiesel, which develops 442lb ft, it could match the XF 3.0D’s 0-60mph in 5.9sec, 50-70mph in 3.2sec and 42mpg combined economy.
That would put the Jaguar XK D close to the new 5.0-litre V8 XK’s 0-60mph in 5.2sec and 50-70mph in 2.5sec, themselves impressive figures, since they match those of the outgoing XKR.
Another possibility is for the diesel to be held in abeyance until an all-new XK arrives in 2014 or 2015.
That car could grow in size to become a full four-seater like the Maserati Gran Turismo, leaving space for the Boxster-chasing front-engined XE two-seater.