The facts on the 2010 Touareg TDI Clean Diesel

April 8, 2009 -- Filed under Technology by Louis-Alain Richard

Everyone has had a chance to see Volkswagen’s Touareg: the mid-size SUV has, after all, been on the market since the fall of 2003. Most reviewers, including your humble servant, agree that its main qualities are exceptional finish, surprising climbing ability, and outstanding mechanical refinement. However, these same reviewers also mention excessive fuel consumption for its size (the V6 Touareg is close to 2,300 kg), and an “elitist” price. To correct these negative aspects, Volkswagen will offer the Touareg in a V6 TDI Clean Diesel version this spring (the TDI engine has been specially developed for the North American market). In the meantime, just to give you a taste of the vehicle before I get my hands on one from VW’s press fleet, here are a few of its main features.

First of all, a few words about the engine itself. This V6 is made up of a cast engine block with 90° cylinders and displacement of 2,967 cm3. The bore is 83 mm and the stroke is 91.4 mm, which makes it a long-stroke engine, an important feature that maximizes torque. The aluminum cylinder heads each have four valves and two camshafts per cylinder row. This 24-valve DOHC arrangement is typical of modern gas V6 engines as well. Camshaft drive is by chain, so there’s no need to ever replace a timing belt, because there isn’t one. The oil reservoir has a capacity of 8.2 litres, which is more than enough to ensure proper lubrication and cooling.

This common rail direct injection V6 can pump out 225 hp and 406 lb-ft of torque. The Touareg’s current engine, the 3.6-litre VR6, delivers 280 hp and 265 lb-ft of torque. So the TDI version is 20% less powerful than its gas cousin but offers 50% more torque, which is available between 1750 and 2750 rpm. Furthermore, this 406 lb-ft of torque surpasses what offered the old 4.2-litre V8 (310 lb-ft). Torque at such low rpm should make for exceptional off-road capability. It comes as no surprise to learn that the Touareg won the most recent Dakar rally.

As far as fuel-efficiency goes, the VR6 offers 14.8L/100 km (city) and 10.3L/100 km (highway). The first tests carried out on the Touareg TDI in the U.S. have given results 20% lower on the highway and 25% lower in the city. If we extrapolate these figures using Canadian values (which are slightly less than the American EPA’s), we can expect to get something around 11.5L/100 km (city) and 8.2L/100 km (highway). We’ll have to wait and see if Transport Canada agrees with my perfectly empirical calculations.

The Touareg’s 3-litre TDI V6 also sports an improved anti-pollution system that uses urea injection. The other components remain unchanged: automatic 6-speed transmission, transfer gearbox with two gear ratios, permanent all-wheel drive with three differentials, the central one with automatic or manual lock, independent suspension with long travel, oversized braking system, and multi-piston callipers (20 in all). The Touareg’s off-road capacity is still just as impressive: it can cross a 50-cm deep river and climb 100% (45°) slopes. I can’t wait to check all this out!

And what do you think? Is the new TDI Clean Diesel engine a real plus for the Touareg? Let’s talk.

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