Any four-cylinder engine in the nose of a line-leading mid-size premium saloon (or its estate derivative) has questions to answer not only regarding performance but also personality. Effortless pace with enviable mechanical refinement is the order of the day, and in this class of car manufacturers have traditionally deployed half a dozen cylinders or more to achieve it.
Straight away there are concerns. In terms of outright thrust, the most powerful Ingenium engine acquits itself well enough, helping the car to 60mph from rest in 6.6sec. Even with no dedicated launch control program, the four-wheel drive system channels torque cleanly, and the resulting sprint is only a second or so behind today’s similarly powerful front-drive hot hatches –and that’s no shame when you consider the Jaguar’s greater mass and practicality.
Judged against a claimed 0-60mph time of 5.7sec and recorded on a dry day, however, our test car’s efforts nonetheless warrant a raised eyebrow of circumspection: a flagship estate car from a performance-orientated brand could, and should, be quicker.
The XF Sportbrake’s in-gear acceleration is also less impressive when compared with the six-cylinder alternatives – particularly those powered by diesel. As an example, the BMW 630d GT we tested in 2017 dispatched the 30-70mph dash in fourth gear almost a second quicker than our XF Sportbrake, and out on the road, away from the stopwatch, the Jaguar’s relative lack of torque does tell. Despite peaking early, with 295lb ft delivered from only 1500rpm, truly effortless progress still depends on the gearbox operating either in Sport or manual modes, and on keeping engine speed close to 3000rpm. Thankfully this is no chore for ZF’s eight-speed automatic, which operates smoothly and predictably, even if the same hardware seems to shift with greater dexterity in BMW’s 5 Series Touring.
But even if it doesn’t fire itself down the road as enthusiastically as it might, the XF Sportbrake certainly sheds speed with confidence. Neither too generously servoed nor too keen to bite at the top of the pedal travel, the car’s brakes feel reassuringly natural, and a 46.4-metre emergency stop from 70mph very nearly matches that of the lighter, lower 2.0-litre F-Type with which the XF Sportbrake shares its engine.
Ultimately, resorting to power from four highly tuned cylinders does little to diminish the flagship XF Sportbrake’s usability, but it does nothing to enhance its subjective appeal. There are, however, benefits to downsizing, as we’ll come on to.