I've come up with a great idea for a new Olympic sport. It's called extreme road testing, and when you consider how popular it is to iron clothes on top of a mountain, or to skateboard naked off skyscrapers, it's bound to be a winner. It should also be pretty useful too - especially when it comes to proffering opinions on vehicles such as the Volkswagen Touareg.You see, the problem with the Touareg and its ilk is that the average road test rarely causes such cars to break into a sweat - what's needed is something altogether more rigorous. Therefore, let me introduce you to the extreme road test, where we ask rather more of the car than 50 miles on a congested A-road.To be fair, most road tests of off-roaders put the car into a situation that mirrors reality for the great majority of buyers. That's why SUVs don't make much sense for most people, for most of the time. With off-roading off the menu for the typical SUV driver, there's nothing the Touareg can do that's beyond the capabilities of a decent premium estate for the same money. However, bung a heavy trailer on the back and take it over fields, and the car really comes into its own, thanks to the generous ground clearance and four-wheel drive.The thing is, there aren't many people who need to tow a heavy trailer on the rough stuff. Perhaps there's an opportunity for a follow-up extreme sport involving taking caravans across fields at high speed, but for anyone who does hot air ballooning, the Touareg could be just the ticket.Well, I don't know what the chances of this are, but I happen to help a friend out every so often when he's on a ballooning excursion. So what better way to put a Touareg through its paces than by sticking his 1.5-ton trailer on the back, scooting up the motorway to Yorkshire, then dragging the thing round various fields?Having latched the trailer onto the Volkswagen's rump, the journey north went without a hitch, as it were. As we cruised up the M1 at 70mph, the Touareg was utterly unruffled. It didn't feel as though there was anything on the back, with the VW feeling completely stable at all times and plenty of power in reserve.Even under continuous braking down steep Yorkshire hills, the braking system remained completely reassuring, with no sign of fade. Even better was the fact that although it was over 30 degrees outside, the interior was kept at a steady 19 degrees; the car's climate control system is a belter.Having driven a Touareg 2.5 TDI, as well as one sporting the outrageous 5.0 V10 TDI unit, I can safely say that the 3.0 TDI lump is the one to go for. The smaller powerplant isn't really up to the job while the bigger one is utterly pointless - if somewhat glorious.The 3.0 strikes the right balance between peformance and economy, because once we'd left the trailer behind the Touareg was amazingly quick; floor the loud pedal and it just takes off, leaving everyone wondering what happened thanks to the stonking 369lb/ft of torque on offer. However, sit at the motorway limit and you can easily achieve 30mpg - which is pretty good going for a vehicle that tips the scales at a hefty 2530kg.Choose the 3.0 powerplant and you get a Tiptronic transmission with no manual alternative (although the Tiptronic does offer sequential manual changes). It's a great unit that swaps cogs imperceptibly, and if you're feeling lazy but you want to press on, there's always the Sport mode that holds onto the gears longer as you race through the ratios. As a package, this engine and transmission suit the car perfectly and it's hard to see how it can be bettered - other than in terms of even better fuel efficiency.Also impressive is the way you can hustle the Touareg along and not have to scrub all your speed for the corners; with 295/45 R19 tyres the Altitude hangs on amazingly well through the bends. However, if you need to pull up in a hurry the all-disc braking system is astonishingly efficient, helped partly by the monster rubber.Although such generously proportioned wheels don't help the ride quality, it's nothing like as crashy as you'd think it would be. If SUVs figure prominently in my Room 101, oversized wheels will be pretty close behind. While they may look great, get them anywhere near a kerb and they're soon wrecked. Sure enough, while reversing the trailer in a confined space I brushed a kerb, and one of the standard 19" units fitted to this Altitude was forever tainted.With the exception of those alloys, the Touareg is somewhat understated, yet it was amazing how many admiring glances the Touareg attracted on our world tour of Yorkshire. Perhaps it was those wheels or maybe it was the twin exhaust pipes, but whatever it was, people seemed to like it - and that was without sampling the creamy smooth engine and transmission or the generously equipped interior.It's also not as though this was even the barking mad V10 version. Now that's a car that's just crying out for some extreme road testing . . . Engine 2967cc, 6 cylinders Power 225bhp Transmission 6-speed semi-automatic Fuel/CO2 25.9mpg / 287g/km Acceleration 0-62mph: 9.9 seconds Top speed 127mph Price £37,855 Details correct at publication date