Jaguar's XF is well regarded but has previously been available with a far narrower range of engine and body options compared with its German rivals, the BMW 5-Series, the Mercedes E-Class and Audi A6. Jaguar made the first step towards widening the XF's appeal last year with the introduction of a 2.2-litre four-cylinder diesel engine option, now available in two different states of tune, and the handsome Sportbrake should help boost sales further.