Porsche Panamera diesel vs Jaguar XJ

Both our contenders prove that fast, fun and luxurious saloons needn’t always run on petrol. But which one comes out on top? Based on looks alone, the sleek Jaguar is certainly worth considering. Adding to its appeal are a sumptuous cabin, strong performance and impressively long list of standard equipment. It’s not perfect, though. Disappointing fuel returns and a fidgety ride are particular bugbears, while the lack of eco-friendly technology means high emissions. In contrast, the Porsche employs stop-start and a slick eight-speed automatic gearbox to drive down CO2 and slash fuel use. Better still, these additions don’t come at the expense of straight-line pace. Factor in the excellent driving dynamics and superior long-term running costs, and the Panamera takes a narrow victory ahead of the capable XJ.

On this showing, Porsche fans should have nothing to fear from diesel. In fact, this latest Panamera is arguably the best in the saloon line-up. It’s fast, frugal and fun to drive, and will be a hit with keen drivers. Yet it’s also very comfortable, cosseting and spacious. The only issue is the slightly awkward styling.

Eye-catching looks, an upmarket cabin, generous kit and an attractive price tag will persuade most buyers to part with their cash. The XJ has lots of character and is a relaxing long-distance express. But it’s held back by high running costs, a less composed chassis and poor low-speed ride.