LOS ANGELES, California - A British team has crossed North America from New York to Los Angeles in a Jaguar XF 2.2 diesel and recorded some remarkable fuel-consumption figures.The XF, according to the car's trip data computer, returned 4.49 litres/100km for the 4641km trip and that, Jaguar says, makes it the most economical Jaguar yet built. Way better than the seven/100 achieved on a trip to Germany.'EVERY ELEMENT EFFICIENT'The eight-day trip ended in Los Angeles, California on Monday, November 14; the journey - the equivalent of Cape Town-Johannesburg-Cape Town - crossed 11 states and three time zones yet the XF needed only four stops for fuel – its peak economy of 4.2 litres/100 being achieved on the penultimate day.Paul Alcock, XF project manager, who was present throughout the journey, commented: "This project was designed primarily to test the fuel economy of the XF 2.2. The figures achieved were accomplished by making every element of the new XF as efficient as possible – from its aerodynamics to its four-cylinder, 2.2 diesel engine and eight-speed transmission."The whole XF team is incredibly proud of what's been achieved. It's a graphic demonstration of the strength, engineering integrity and efficiency of the car." COMPUTER CONFIRMATION: The full story of the trans-America trip is right there on the Jaguar XF's trip data computer (though in miles and gallons). The Jaguar was driven by independent testers David and Alexander Madgwick and Jaguar says it was a scrupulously standard, UK registered, right-hand drive model. In the course of the coast-to-coast adventure the car maintained an average speed of 85km/h and drove through many real-life scenarios including the busy roads of New York and, towards the end of the trip, road works, strong winds and a climb to more than 2200m above sea level.While fuel-frugal, the diesel XF is capable of eight seconds to 100km/m and top speed of 225km/h.The project has been broadcast live on Twitter and Facebook as Jaguar's senior media officer, Faye Goldstraw, travelling in a support vehicle, charted the progress of the car as it crossed America.