Jaguar has updated its XK coupe and convertible range with larger, more powerful V8 engines and a six-speed automatic transmission.

There are two new 4.2-litre V8 engines, a 300bhp naturally aspirated unit and a 400bhp supercharged one.

The electronically-controlled, six-speed automatic transmission made its Jaguar debut in the new S-type R. Built by ZF, it is the first example of a 'stepped' (as opposed to CVT) six-speed automatic transmission.

Though the latest cars look no different inside and out at first glance, Jaguar claims there are about 900 part number changes.

Changes include new colours, wheels and badging while, under the skin, there are suspension and braking tweaks and the addition of dynamic stability control and emergency brake assist as standard. XKR models now have Xenon headlights.

An electrically adjustable steering column with entry/exit mode is now standard on all models and new equipment options include upgraded DVD-based navigation system and electrochromatic mirror with compass.