We've known for quite some time now that Jaguar ->ke39 has been hard at work on the next-gen XF. Despite the knowledge, this is the first time we've had the chance to catch a mule of the new XF -- basically a current XF with the new drivetrain and chassis underneath -- testing. Our spy photographers managed to catch this powertrain and chassis mule somewhere outside the Jaguar test center at Nürburgring->ke999.

The next XF ->ke1236 will offer some major updates over the current model. First and foremost, it will move to a modular, aluminum platform that Jag is calling the iQ(Al) -- the same platform also sees use under the BMW 3 Series->ke290. This change will make the new XF a lot lighter than the current model, which will make it more nimble and improve its fuel economy.

Under the hood, the engine lineup will range from a brand-new four-cylinder engine to a powerful V-8. The new platform is optimized for all-wheel drive, so we expect to see more AWD Jaguars in the future.

The new XF is expected to be revealed as a concept in 2015 with the production car to arrive in 2016.

Click past the jump to read more about the next generation Jaguar XF.

Spy shots

Of course what we saw today is just a mule, so it doesn't reveal anything about the new model. We expect the next XF to continue the tradition started by the current model, but with a modernized look and elements inspired by recently launched Jaguars, like the F-Type.