TINKERING with your best selling model to update it is always difficult for car makers.

Do something too radical and you could put potential buyers off. Opt to make too few changes and you won't freshen the car up enough to keep sales flowing in at the same rate.

Kia's fourth generation Sportage is new from the ground up but you won't have any difficulty spotting it because the basic shape remains the same.

Park it alongside the outgoing model, however, and you will see the differences.

The new model has grown in length which has allowed for an extended wheelbase and shorter rear overhang which - with a more rakish design - ensures an even more sporty look than before and that's important, because even though it is an suv it's the Sportage's flowing sporting lines which have made it so popular.

There's a new grille, a sculpted bonnet, elongated projector-like headlights and what Kia calls a chiselled rear end to make the newcomer more easily recognisable from the car it replaces.

The new Sportage comes in five trim levels and this car was the "2", one up from the basic model but still very well equipped with features like a touch screen navigation system, roof rails, folding door mirrors, cruise control, privacy glass, dual zone air conditioning and a rear view camera plus parking sensors.

The car was powered by Kia's most popular engine, the 1.7-litre CRDi, which has been bought by more than half of all Sportage buyers.

This 114bhp unit has been improved for the new, fourth generation Sportage and now boasts an additional seven miles per gallon and a 16g/km drop in CO2 levels.

It's a gutsy performer which seems to move a lot quicker than the official 0-60-mile an hour acceleration time given by Kia of 11.1 seconds.

Driving the Sportage it's soon obvious why it's so popular. It's an easy car to drive, offers plenty of leg and head room not to mention generous boot space of 491 litres with the seatbacks in place.

Lower the seatbacks and you not only get 1,480 litres of space but also a completely flat floor to make loading easier.

Inside the new car is quieter and more comfortable - thanks to better padding in the seats - and the stylish dashboard features soft touch material although there is still a lot of black plastic around.

There's plenty of adjustment on the driver's seat but I did get some complaints from front seat passengers, every one of which felt they were sitting too low and there is no height adjustment on that seat.

But that apart the new Sportage is an impressive car which is ideal for family buyers and fleet customers.

This Sportage was a front-wheel-drive model but for anyone with off-road aspirations four-wheel-drive models are still available in the new line up with prices ranging from £18,000 to over £30,000