Could this be the fastest SUV in the world? German firm VW has pulled the wraps of its new high performance Touareg, the R50.The new range-topper features a tweaked version of the company's 5.0-litre V10 diesel that now pushes out 345bhp - and increase of 37bhp over the standard car. Even more impressive is the peak torque figure, which rises from 750 to 850Nm. As a result performance is blistering with the Touareg sprinting from standstill to 62mph in 6.7 seconds and onto a top speed of 146mph. However, the fuel economy and CO2 emissions remain the same as before at 22.4mpg and 333g/km respectively.To cope with the extra performance, VW's engineers have fitted the R50 with springs that are stiffened and lowered by 20mm. This is in addition to the grippy 4MOTION all-wheel drive systems and smooth-shifting six-speed auto gearbox.Externally, the newcomer is distinguished by an 'R' design package that comprises a roof-mounted spoiler, wheel arch extensions and matt chrome front grille. There's also distinctive 21-inch alloy wheels, blue brake callipers and twin oval exhausts.Climb into the cabin and you'll find 'R' logos embossed on the heavily bolstered Nappa leather sports seats, kick plates and pedals. The luggage compartment gets a special ski sack and net partition.However, VW won't have it all its own way in the rapid off-roader sector. Later this year sister firm Audi will launch its Q7 V12 TDI, which is capable of covering the dash from 0-62mph in a staggering 5.5 seconds.Until then the R50 will remain undisputed performance heavyweight champion. If you want one then you'll have to be quick as only a limited number will be brought to the UK, each priced at £61,885.