AUDI has already proved its diesels have the venom to win at Le Mans and now such high performance technology is hitting the road in an SUV.

The latest SQ5 has just been given what Audi calls the plus treatment and it has turned the first diesel powered S model in the German brand's stable into a 4x4 with supercar pretentions.

A power hike takes the biturbo 3.0-litre diesel engine up to 340ps but more importantly there's extra torque and it's allied to a sport differential integrated in the back axle of the quattro all wheel drive set up.

And while the performance data is no different to that of the regular SQ5 - which is a very brisk 5.1 seconds 0 to 60 with a restricted maximum of 155mph - the power in the plus model is much more usable.

The SQ5 plus is at full chat between 1,500 and 2,250 rpm and the added bite from such a low part of the rev band is noticeable. So is the agility and for a two-tonne SUV it handles in a very accomplished fashion.

Like for like, the plus version has an extra 14ps over the standard SQ5 and 50Nm more torque at 700Nm which blows away anything offered by BMW or Range Rover.

Fuel economy is also unaltered with Audi claiming an official return of 42.8mpg and emissions of 174g/km even though the plus sits on 21-inch rims as opposed to the 20-inch wheels on the normal SQ5.

That's not too far off the mark in real world terms and we managed to notch up an average of 34 to the gallon without sparing any of the many horses under the bonnet during a drive through the lanes of Leicestershire.

The SQ5 plus is priced from £51,850 and that is almost £6,500 more than Audi charges for the SQ5 in non-plus guise.

As well as the extra power, the sport diff and the bigger wheels the plus gets additional kit in the form of sat nav, a powered tailgate and some styling upgrades including privacy glass and black gloss door mirror caps.

They all set the car apart and for those who crave something special it is a vehicle with stand out appeal - not to mention its feisty performance and when let loose there's a splendid growl from the four exhausts.

Around town it is a docile as a lamb, stop/start kicks in when stationary and the eight speed auto box is smooth under all circumstances.

Paddle shifters can be brought into play and so can a sports mode while for more traditional SUV purposes the car retains hill descent control should it ever venture off road.

Compared to the standard Q5, even in high grade specification, then the SQ5 plus is a £12,000 indulgence but it is an SUV of the highest calibre and a super-diesel to be relished.