The old 4.0-litre units are replaced by larger, more powerful 4.2-litre V8s already in the S-Type, while the XK also borrows its stablemate's six-speed automatic box. The normally aspirated engine now generates 300bhp in the XK - up from 290bhp - and propels the coupé from 0-60mph in 6.1 seconds. The supercharged XKR - at 400bhp, up from 370bhp - can hit the same mark in only 5.2 seconds. Both cars have an electronically limited top speed of 155mph. To help owners cope with the extra power, Dynamic Stability Control and Emergency Brake Assist are fitted. Adaptive Cruise Control, which features forward alert - an audible warning system that senses when traffic ahead is slowing down - is offered as an option. But if the XK isn't enough for you, a range of extras featuring Jag's R performance badge are available, including Recaro seats, Brembo brakes and a variety of interior details.