RESTON, VA – Europe’s largest-volume seller of turbodiesel engines for light vehicles, Volkswagen AG, unleashes to its Volkswagen of America arm two new diesel-powered models to magnify the auto maker’s exposure of diesel power to North American customers.

With U.S. gasoline prices continuing to spike in excess of $2 per gallon, VWoA couldn’t have picked a more opportune time to expound the gospel of the new-age diesel.

Touareg TDI mightier than the brawny Hummer.

And although its two new-to-the-U.S. diesel models powered by the company’s cutting-edge TDI (turbo direct injection) technology – the Passat TDI and Touareg TDI – are polar opposites in performance and price, both are formidable efforts that will force gasoline-powered competitors in their respective segments to take notice.

Note to those who still think the biggest, baddest, most outlandish SUV available to civilians is General Motors Corp.’s Hummer H2: You’re so five minutes ago.

Volkswagen’s new Touareg TDI packs a 5L V-10 variant of the TDI with 310 hp and a Warsaw Pact-violating 553 lb.-ft (750 Nm) of torque.

The V-10 TDI turbodiesel is a technical showcase.

The V-10’s mighty torque twist leaves the Hummer 6L gasoline V-8, at 325 hp and 365 lb.-ft. (495 Nm), looking positively wimpy, not to mention surpassing the performance of Touareg TDI’s gasoline-slurping V-8 counterpart. The Touareg with a 4.2L gasoline V-8 brings an identical 310 hp to the party, but passes out early with a comparatively meager 302 lb.-ft. (410 Nm) of torque.

We are no fans of the Touareg’s unconscionable curb weights. The TDI model tops all versions at a truly scandalous 5,825 lbs. (2,642 kg). So it’s testimony to the V-10 turbodiesel’s sheer grunt that even through the standard 6-speed automatic, it can launch the Touareg TDI to 60 mph (97 km/h) in 7.5 seconds. The V-8 Touareg does the same run in 7.6 seconds.

And of course there is the fuel economy, diesel’s traditional trump card: 17 mpg (13.8L/100 km) city and 23 mpg (9.2L/100 km) highway.

Most SUV drivers who never see the north side of 15 mpg (15.7L/100 km) gleefully would take those figures, which are more in line with the wheezy 4-cyl. quasi-SUVs such as the Honda CRVs and Toyota RAV4s – not a luxo-ute that can tow 7,700 lbs. (3,500 kg) as easily as you toss your cat off the armchair.

What’s more, that’s real-world fuel economy, not the mpg shell game the hybrids play. We caned the Touareg TDI on the Virginia backroads here for an entire evening and couldn’t drive the average below 15 mpg.

And stand back BMW and Honda, because this “lowly” diesel may be the most sophisticated light-vehicle engine on the planet.

Once you get over the superficial disappointment of the SOHC/2-valve-per-cylinder valvetrain, it’s a tech-geek delight: all-aluminum construction with cylinder walls plasma-coated with wear-reducing material; twin turbochargers with electrically adjusted vanes; intercooling not only of the intake charge but also the recirculated exhaust gas and an exquisite gear drive for the valvetrain and ancillaries that eliminates drive belts.

And of course, the direct fuel-injection system uses VW’s exclusive combination fuel pump/injector for each cylinder to generate the spectacular 29,700-psi (2,050-bar) injection pressure that quiets the diesel chatter and maximizes power and fuel economy.

The Touareg, itself, already is known as perhaps the most sumptuously appointed and full-featured SUV this side of a Range Rover.

Being that the Touareg TDI also serves as the flagship of the line, there is all the luxury and pampering one can endure (our tester proffered delicious saddle-quality and -look leather), while it’s hard to argue that the sheetmetal wrapper, while not adventuresome, is appealingly genteel.

The stunning V-10 turbodiesel and all the other Touareg niceties that come with the TDI package are unfortunately dear, however. A $57,800 base price glides easily into the low $60,000 range by adding a couple of the alluring options that probably should be standard for a vehicle with such an ambitious a sticker price. Volkswagen says the 500 earmarked for the U.S. will doubtless find homes (though we saw a few offered by dealers on eBay).

At the other end of the scale – by almost any measure – is the new Passat TDI. Though it has fewer than half the Touareg TDI’s cylinders, the Passat gets along quite nicely, thanks, with a 2L 4-cyl. turbodiesel that also utilizes all the TDI components, but produces a less-bombastic 134 hp and 247 lb.-ft. (335 Nm) of torque. As with the Touareg, the only available transmission is a sequentially shiftable Tiptronic automatic, the Passat’s enjoying five forward speeds rather than six.

The Passat TDI’s horsepower figure is meager for a midsize sedan when you consider the Passat competes with 6-cyl. Nissan Altimas shoving 250 hp through the front wheels and numerous midsizers with 4-bangers making 160 or 170 hp. But again, the torque’s the thing, and once underway, one quickly forgets the unhurried 10.2 seconds it takes the Passat TDI to gather itself up for the 0-60 mph jaunt.

The Passat TDI’s first forte is in-gear acceleration: Stomp it at 70 mph (113 km/h) and it hauls itself to 90 mph (145 km/h) with verve – serious enough to drop a lot of 6-cyl. midsizers like a bad habit. Much the same is true at around-town speeds.

The second grin-inducer is the Passat TDI’s parsimony. The official figures are 27 mpg (8.7L/100 km) city and 38 mpg (5.7L/100) highway. Some time after the two new TDIs’ introduction here, we flogged the Passat TDI for two weeks. The average was 38 mpg, and we never felt particularly shortchanged on performance.

Fuel-sipping like that isn’t really appreciated until you realize you can’t remember whether you bought fuel last week – or was it the week before?

There are two bodystyles for TDI-carrying Passats, sedan and wagon, and the price starts at $23,060 and $24,060, respectively – $205 more than their 4-cyl. gasoline counterparts.

For those who insist on measuring diesel’s worth in “payback” time, VW’s pricing is hard to ignore. We’ve seen some groaning at VW and diesel enthusiast websites that VW’s not offering enough variation for the Passat. The diesel junkies want a manual transmission (we can’t argue there), and many want the option of VW’s 4Motion all-wheel drive (that’s getting picky).

Zafar Brooks, VW’s general marketing manager-U.S. and Canada, says the enthusiasts have to relax until diesel is more established in the U.S. Then there may be room to offer the same variants and features Europeans enjoy.

Moreover, all VW diesel-powered models are limited to sales in the 45 states that accept compliance with federal Tier 1 emissions standards – California and four other states levy more stringent standards that diesels currently cannot meet.

Regardless, both the Passat TDI and Touareg TDI are convincing showcases for the benefits of diesel technology. One is a bit pricey, one isn’t, which illustrates the contemporary turbodiesels’ ability to serve as a premium performance engine – or deliver return on your investment with its traditional economy.