In Range Rover terms, the Sport is a compact vehicle. It would not be stretching things too far to suggest that it is the hot hatchback of the range, nimbler and fleeter than the luxury saloon that is the Range Rover proper. Yet when you encounter the Sport on its own, with no related products within sight, it hardly strikes you as a sporty machine. Stand beside one and it can seem almost intimidatingly large - or, if you prefer to look at it this way, conveniently large, with the ability either to convey five adults or to carry just two along with a maximum of 2013 litres of luggage volume.As we've mentioned before, it is not actually a Range Rover at all. It looks like one, because the folk in charge reckoned that Range Rover owners might like the idea of a sports model while Land Rover owners almost certainly wouldn't. The fact remains, though, that this is in all important respects a third-generation Land Rover Discovery. The underpinnings are identical, the engine line-up is the same, the more complex electronic Terrain Response transmission trickery is in place (which is not the case for the "real" range Rover) and the interior is absolutely standard Discovery with the exception of the wider central console.Even with Terrain Response fitted, the Sport is a relatively modest achiever in off-road terms, at least by Land Rover's general standards. It actually performs brilliantly in the gloop, but a relatively low ride height (varying between 172mm and 227mm depending on suspension mode) means that ground clearance is more limiting than it is on the Discovery.On the other hand, if it's now well understood that few owners of higher-specification Land Rovers as a whole actually go off-roading to any significant extent - even though they have the means to do it to a very advanced level - this is most particularly so when it comes to the Sport. Style, branding, luxury and visibility are all higher priorities, and so too is its behaviour on properly-surfaced roads.The company says that this is "the best-performing and best-handling vehicle" it has ever built. There can be few arguments about this. Present-day Range Rovers and Discoveries are, considering their bulk, amazingly quick, quiet and nimble, and the Sport is the best of them all in these respects. But shift the point of reference - compare the Sport with any luxury vehicle you might otherwise choose - and its massive weight (yes, though it's smaller than the Range Rover) and great height (yes, it's lower too) become very obvious.The Sport rides amazingly well, all things considered, and has levels of grip which seem extraordinary when you think of what the tyres have to deal with, but from behind the wheel there is never any doubt that you have an awful lot of car underneath you.Our test car came with the excellent 2.7-litre TDV6 turbo diesel engine also found in, for example, the Jaguar XJ, and it was ironic that it was in our hands just at the time when Land Rover announced that it would be replacing this unit with a new V8 version. Well, enjoy it while you can. This is a magnificent engine which gives the Sport better real-world performance than the 4.4-litre petrol, and uses far less fuel than the supercharged equivalent. It's also one of the best-sounding diesels around, and in fact makes a sweeter (and at the same time more subdued) noise than the old four-litre petrol V8 ever did in previous-generation Range Rovers.The quoted combined economy figure of 27.6mpg is easily achievable, but watch out for the range predicting function on the trip computer. It spent a long time telling me that I would manage well over 500 miles on a single tank, but panicked at the last minute and persuaded me to retrace my steps to the last fuel station if I didn't want to get out and push. From the moment the warning light to the time I pulled up to the pump with the computer telling me there was no fuel at all and that any forward motion was a figment of my imagination, I covered no more than 30 miles, adrenalin surging freely during the last five.It's possible, of course, that the computer was just being pessimistic, but I'm the man who once ran out of diesel in a Freelander 18 miles after the warning light came on. I'm learning to be mistrustful.That apart, the Sport was a good companion. It's not cheap - you can spend £5000 less or £4000 more than the forty grand asked for the SE-spec test car, and blow quite a lot more on a wide range of accessories - but it costs less than any of the petrol models, and is, I think, as good as if not better than them. Engine 2720cc, 6 cylinders Power 187bhp Fuel/CO2 27.6mpg / 271g/km Acceleration 0-60mph: 11.9 seconds Top speed 120mph Price £40,000 Details correct at publication date