Diesel engines operate with very high levels of compression. Although not known for their ability to rev at high speeds,
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| The diesel-powered Touareg ran as cleanly as any gasoline-powered SUV I've tested. (Photo: Rob Rothwell, Canadian Auto Press) |
they generate tremendous torque at low rpm levels and consume fuel at a miserly rate. It's this combination of characteristics, combined with a reputation for endurance, which make the diesel so darn appealing. Gone are the days of waiting for the glow plugs to heat up before twisting the ignition. Today's diesels fire-up like any other passenger car engine. Once in operation, the modern diesel runs quieter and cleaner that those of yore. I occasionally caught a brief whiff of diesel exhaust during my road testing, but it was only when the window was open and I was reversing into my garage. Otherwise the Touareg ran as cleanly as any gasoline-powered SUV I've tested, and I never detected a contrail of black smoke behind me, even when maximum acceleration was ordered.
And let me add to that, acceleration in the V10-TDI Touareg is startling to say the least. I've driven many diesel-powered vehicles in the past and their acceleration abilities have never inspired me. Sure, you might get a kick in the rear off-the-line thanks to a diesel's low-end torque, but it's generally a kick without follow-through - and as any self defense coach will affirm, failing to follow-through with
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| The Touareg's startling 553 foot-pounds of torque is delivered at a modest 2,000 rpm. (Photo: Rob Rothwell, Canadian Auto Press) |
maximum force when kicking will diminish the strike's effectiveness. The Touareg's 10-cylinders and twin-turbocharger boosting gives it follow-through that would make any coach proud. Its 553 foot-pounds of torque is delivered at a modest 2,000 rpm, and stays delivered as the tachometer rushes toward the TDI's generous for-a-diesel redline of 4,400 rpm. Compared to a hi-tech gas engine, a 4,400-rpm redline is dramatically low, but the Touareg TDI makes up for a curtailed rev band by sending its mammoth torque to all four wheels through a 6-speed autobox, featuring VW's Tiptronic manual-mode shifting. The wide range of gear ratios offered by six cogs easily compensates for the shortened duration spent in each gear during full acceleration. The pay-off is performance that is downright neck snapping and persistent through a run up the ladder.
