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New Car Reviews : 2005 VW Touareg and TDI Passat TDI - New Diesel Powered Models From Volkswagen

PHOTO (select to view enlarged photo)

PHOTO (select to view enlarged photo)
VW Touareg V10 TDI

By Carey Russ

Volkswagen has two new vehicles, the Passat TDI and the Touareg TDI. As you can tell by the ``TDI,'' they're diesels, and, while they join the existing Golf and Jetta TDI models, the new Passat and Touareg models feature some new and very innovative technology that helps make them clean, powerful, and economical.

The Passat is already a major success for Volkswagen, and the new TDI models will further that, adding a choice for people interested in excellent fuel economy with space and power for everyday and long-distance use. And distance is a definite possibility - according to Volkswagen, it can go up to 623 miles on a tank of fuel. The Touareg sport-utility has established VW as a presence in the SUV market, with versatility, capability, and comfort in a large, but not too-large, package. The Touareg TDI, to be available in limited numbers, slots in at the top of the Touareg range by virtue of its strength. With 310 horsepower and a massive 553 lb-ft of torque, it's one of the most capable large sport-utilities made. Yet it is rated at 17 mpg city, 23 mpg highway, considerably better than any similarly-sized SUV.

Both TDI models share some innovations that helps them run cleanly and efficiently. Volkswagen is already the largest passenger diesel producer and a diesel technology leader with the TDI engine. ``TDI'' stands for Turbo Direct Injection, meaning that not only is the engine's intake air compressed by a turbocharger for greater efficiency, the fuel is injected separately and directly into each cylinder at the appropriate time, not into the intake manifold as in a gasoline engine. Sophisticated mechanical and electronic systems control the amount and timing of each fuel charge for maximum power output with minimum emissions. But direct injection as done by previous TDI engines has been improved upon with the new engines. They use ``Pumpe D_use'' (PD) technology developed in conjunction with Bosch Corporation. Translated to English, this means ``unit injectors'' - the injection pump, controls, and injector for each cylinder are in one unit, and there is one unit injector per cylinder. The injection pumps are driven off the camshaft. The design is extremely compact and precise. Fuel efficiency is related to the degree of atomization of the fuel before combustion. The higher the pressure of injection, the smaller the droplets of fuel, and the more complete the combustion - leading to increased power and decreased emissions. Early diesels, in the 1930s, injected fuel at 5,000 pounds per square inch (psi). The PD injectors inject fuel at over 29,000 psi.

The Passat TDI will be offered in both sedan and wagon body styles. Other than the PD injection system, the four-cylinder, 2.0-liter engine is fairly conventional, with a cast-iron block and cross-flow single overhead camshaft eight-valve head made of aluminum alloy. It is rated at 134 horsepower at 4,000 rpm, with 247 lb-ft of torque at 1,900 rpm, and can be matched to a six-speed manual or five-speed automatic transmission. Front-wheel drive GL and GLS trim levels will be available in both body styles. EPA fuel economy ratings are 27 mpg city, 38 mpg highway. Pricing, at $23,060 for the sedan and $24,060 for the wagon, is only $205 over a comparably-equipped gasoline model.

At $57,800, the Touareg TDI is a premium model. Only around 400 examples are expected to be imported this year, so they will be rare. The engine is a 5.0-liter V10. Unusually for a diesel, its block is made of aluminum, for lightness. It is a fine example of efficient power. Twin intercooled turbos, one for each cylinder bank, and the PD system help it make over one horsepower per cubic inch - 310 hp at 3,750 rpm to be exact - and a very impressive 553 lb-ft of torque at 2,000 rpm. In output, it compares favorable with some truck V8s a liter or more larger in displacement, and much heavier. All four wheels are driven through the 4XMOTION (tm) dual-range full-time four-wheel drive system, and shifting is via a Tiptronic (r) manual-mode equipped six-speed automatic transmission. As mentioned in passing, EPA fuel economy is 17 mpg city, 23 mpg highway - ten better than some similarly-sized gasoline SUVs.

Numbers are nice, but how do the new VW diesels work in the real world? Quite well, thank you. Volkswagen recently previewed them to the press in Reston, Virginia, just outside of Washington DC. At the event, I spent one day in both Passat TDI models and one day in a Touareg TDI. Impressions? Glad you asked.

First, the Passat TDI, as it will be the most common. I had driven a European-spec sedan a few months before at Challenge Bibendum, held on the hills of Infineon (nee Sears Point) Raceway. It seemed more than adequately powerful, coping well with the steep hill from Turn 1 to Turn 2, but five miles is not enough to get more than a very brief impression. 250 miles through northwestern Virginia, and parts of West Virginia and Maryland on both scenic back roads an major highways showed both versions of the Passat TDI to be impressive performers. Although a quiet diesel sound can be discerned from outside the car when it is running, it's not an overpowering clatter. Inside, there is an unusual and distinctive exhaust note audible, but it is not particularly loud, and not at all unpleasant. Interior noise levels are equal to those of other Passats, pleasantly quiet if not quite expensive luxury-car quiet. Ride and handling, again, are the same as as other Passats - very good for a mid-sized, mid-priced family sedan or wagon. The TDI does not have the performance of the Passat V6 or W8, but it is quick enough for the real world, and has better acceleration than any current hybrid. Zero-to-sixty is given as 10.2 seconds for the sedan and 10.4 for the wagon. Both are a little sluggish right off the line, but once revs hit the torque peak at 2000 rpm, it moves very quickly. Checking the trip computer during my drive showed almost 33 mpg average fuel economy, not bad at all as I was not driving in light-footed economy mode at all. For almost anyone looking for the space and comfort of a mid-sized sedan or wagon, and with a desire for fuel economy, the Passat TDI is an excellent choice.

If the Passat TDI was designed for economy over speed, the Touareg TDI was meant for power and economy. You can't argue with 553 lb-ft of torque, and you will be reminded of that every time you step on the (drive-by-wire) throttle. The traction control light comes on all too easily, this beast has serious torque and can go from a standstill to 60 mph in 7.5 seconds. It is also remarkably smooth, quiet, and refined. No diesel clatter is audible from inside, and only a subdued sound outside. The ride is smooth and comfortable on well-paved roads, and, because, like all Touaregs, it has four-wheel independent suspension and unibody construction, poor pavement and four-wheel drive trails don't faze it a bit. (And, yes, there was a short 4-low mud section in the Blue Ridge Mountains.) With the adjustable air springs, ground clearance can be varied from 8.7 to 11.8 inches. Towing capacity is 7,716 lbs. (3500 kg.) This is a luxury SUV that has no problem getting seriously dirty, working hard, or driving long distances on any sort of road. The interior appointment level is at the top of the Touareg range, meaning that it features the clean design that is a Volkswagen hallmark, and has plenty of room and a versatile interior.

There is only one drawback to both TDI models, and that applies only if you live in California or the other four states that use California emissions requirements. In those five states, you're out of luck until low-sulfur diesel fuel is available, probably sometime in 2006 or 2007. Diesels have lower carbon dioxide emissions than gasoline engines, but their particulate and nitrogen emissions are higher. The TDI-PD engines meet current European, Canadian, and 45-state American requirements with no problems at all, and should meet the stricter '07 and California regulations with the introduction of reformulated diesel fuel. If you are in the rest of the country and looking for a combination of space, power, and efficiency, take a look at Volkswagen's new diesels.

Press Announcement: 2004 VW Touareg V10 TDI and Passat TDI Introduced to US Market


Offer Maximum Fuel-Efficiency Strength A pioneer in automotive diesel technology, Volkswagen has historically remained the best-selling choice of drivers who prefer a modern diesel engine with advanced efficiency and performance. Just in time for soaring prices at the fuel pump, Volkswagen of America, Inc. introduces two new products to its diesel engine lineup— the 2004 Touareg V10 TDI and the 2004 Passat TDI.

The highly anticipated V10 TDI represents the ultimate extension of the modern direct injection diesel. The muscular 10-cylinder is among the strongest available in any vehicle on the road today. The four-cylinder 2.0L TDI in the Passat represents a major proliferation of high-tech diesels achieving the greatest EPA fuel efficiency rating of any midsize family car sold in the U.S.

Pumpe Düse Helping put to rest the bleak images of tailpipe smoke and noise, Volkswagen’s TDI diesel engines are extremely high-tech, much cleaner and a major departure from what many consumers may remember about old diesel engines. The modern Volkswagen TDI engine is exceptionally efficient and performs smoothly, due in large part to its advanced electronic fuel-injection system that is completely “drive-by-wire”—from the foot pedal to the fuel delivery in the cylinders.

At the heart of the new-generation Volkswagen TDI engine is advanced “Pumpe Düse” technology, as it is called in Germany, or “unit injectors” as translated in the U.S. Developed in combination with Bosch®, these unit injectors are located at each cylinder to deliver the fuel for combustion. Because of exacting electronic control, the new Pumpe Düse technology creates a very high fuel pressure and better atomizes and precisely meters the fuel injection into the cylinders, resulting in increased engine efficiency and power, as well as quieter engine operation and optimized fuel economy.

Touareg V10 TDI The Volkswagen Touareg is already an award-winner and leader in its class: 2004’s Motor Trend’s “Sport/Utility of the Year”; MotorWeek’s “Drivers’ Choice ‘Best of the Year’ and ‘Best Mid-size SUV’”; Petersen 4Wheel & Off-Road’s “4X4 of the Year”; and Car and Driver’s “5Best Trucks: Luxury Sport-Utility Vehicle.” All these accolades came before the newest and most powerful version.

As with all Touareg models, the interior is spacious, with comfortable seating for five passengers and room for plenty of cargo. Interior passenger volume is 99 cubic feet and cargo volume is 31 cu. ft., increasing to 71 cu. ft. with the rear seats folded.

As the saying goes, there’s no replacement for displacement, and the V10 offers five liters in 10 cylinders with twin turbochargers (“biturbo”). The Touareg V10 TDI exhibits the ultimate in tractive force and pulling power. Rated at 310 horsepower at 3,750 revolutions per minute and a maximum torque of 553 lbs. ft. at 2,000 rpm, towing capacity is 7,716 lbs., making this Touareg among the strongest SUVs on the road in its class. It is also one of the fastest diesel SUVs in history, achieving 0-60 miles per hour in just 7.5 seconds and a top speed of 130 mph.

Pleasantly, the Touareg V10 TDI achieves an EPA fuel efficiency rating of 23 miles per gallon on the highway and 17 mpg in the city. It also achieves current exhaust emission performance limits in Europe and 45 states in the U.S.

These impressive performance numbers are accomplished without excessive size, weight or operating noise. Unlike common diesel engines with grey cast iron crankcases and cylinder blocks, the V10 TDI is made with a particularly rigid aluminum crankcase and an innovative grey cast iron bearing tunnel into which combustion forces are introduced directly by way of the cylinder head studs.

The weight-saving aluminum cylinder block enables another important new technology to be introduced—plasma coating of the cylinder walls. This process, developed by Volkswagen and used here for the first time on a production diesel engine, creates a surface layer in the cylinders with a thickness of a few tenths of a millimeter—a few thousandths of an inch—and makes the cylinder walls permanently resistant to deformation and wear.

The “V” arrangement of two rows of five cylinders each allows placement of the main auxiliaries, including the water pump and water-cooled alternator, within the pattern and to be driven by shaft without development of lateral forces. Cross-flow cylinder heads with unit injector fuel supply and two valves per cylinder accommodate placement of the intake pipes within the “V” as well, for further space optimization.

Engine oscillation caused by moving masses is limited to only a few thousandths of a millimeter—a few hundred thousandths of an inch—an operating smoothness that not even many 12-cylinder engines achieve. A balance shaft that rotates at the same speed but in the opposite direction as the crankshaft, along with the usual counterweights on the crankshaft webs, suppresses first-order free inertial moments. A 90-degree cylinder bank and offset crankshaft-throws reduce second-order free moments of inertia. Vibration under load is smoothed by the uniform ignition spacing of 72 degrees between the cylinders, which is achieved by offsetting the crankpins 18 degrees.

A torsional vibration damper on the crankshaft is of a viscous pattern and occupies a space only 24 millimeters—less than an inch—deep. Adding to the compact engine design is a helical-cut spur gear train at the flywheel, replacing the typical timing chain or toothed belt. Keeping everything adequately lubricated is a duplex oil delivery pump and two scavenger pumps that operate reliably even at the extreme angles sometimes encountered during off-road maneuvers.

The new V10 TDI engine owes its lead in the mixture formation, combustion and power-output areas to leading-edge fuel-injection technology, forced aspiration, exhaust gas recirculation and advanced engine management. In addition to the latest unit injector system mentioned before, the fuel supply with five-hole injector nozzles delivers the fuel to the combustion chambers at pressures up to 29,733 pound-force/square inch (PSI). This pressure is a key to the engine’s efficiency and cleanliness and represents a much greater force than what is possible in a common rail system.

Twin turbochargers—one for each cylinder bank in the “biturbo” principle—supply ample combustion air. The turbine blades are actuated electrically versus pneumatically for more accurate control of blade movement. A charge-air intercooler and intercoolers in the exhaust gas recirculation lines increase efficiency. Inasmuch as the V10 TDI can be regarded as two five-cylinder units coupled together mechanically but with separate air intake and exhaust systems, the two units are jointly controlled by interconnected electronic diesel-engine management systems of the latest type and supplied by Bosch.

Development of engines with higher levels than ever of power and torque presents a considerable challenge in terms of converting it for transfer to the wheels. Thus a new six-speed automatic transmission with Tiptronic® manual gear-select ability provides gear ratios that more closely match engine characteristics for more vigorous throttle response. Fuel consumption is also reduced at this power transfer, helped by a hydrodynamic torque converter with lock-up that eliminates power-transfer loss.

The Volkswagen 4XMOTION™ permanent four-wheel drive system with low-range gear and adaptive torque distribution electronically controls the amount of torque transfer between the front and rear wheels.

A durable independent double wishbone suspension up front and an independent four-link suspension in the rear incorporate a four-corner, air adjustable suspension system. With six adjustable ride heights and Continuous Damping Control with three adjustable damping settings, a selectable response is available for differing road conditions. Variable ground clearance ranges from a road-hugging 6.3 inches to a stump-jumping 11.8 in. At the extreme are approach and departure angles of 33 degrees, a fording depth of 22.8-in., and 45-degree hill ascent and descent capability.

The list of performance-enhancing standard equipment on the Touareg V10 TDI includes Electronic Stabilization Program® (ESP) with brake assist, Hill Descent and Climb Assist; four-wheel ABS with power-assisted vented disc brakes; 18-in. alloy wheels; and all-season, snow chain-compatible tires. A four-spoke, leather-wrapped steering wheel with integrated controls for convenient operation of audio, cruise control and onboard computers is also standard and helps keep drivers’ hands where they should be—on the steering wheel.

Interior trim of chrome, brushed aluminum and genuine burled walnut wood and glove-like leather seating surfaces provide an atmosphere of understated elegance. Front seats are 12-way power adjustable, heatable, fully reclining, with lumbar support and driver’s seat memory function. Rear seats are heatable as part of the Winter Package, which also includes heatable steering wheel and a ski bag.

Acoustic characteristics inside the Touareg are on par with many luxury sedans. The vehicle body has excellent acoustic restraint as a result of selective reinforcement of the panel surfaces and the use of highly efficient aluminum “sandwich” designs for damping. A three-part door seal helps shield the interior and passengers from undesirable driving and wind noise.

For added safety, standard equipment on the Touareg V10 TDI includes driver and front passenger front and side supplemental restraint air bags. Side Curtain Protection™, an air bag system that deploys from the roof lining to cover the entire side glass area to better protect both front and rear passengers, is also standard equipment. When any of these airbags deploy, a series of protective measures occurs instantly: all doors automatically unlock, the battery terminal is disconnected from the alternator cable, the fuel supply is switched off, warning lights are automatically switched on and all high-power electrical components are switched off by a load management system.

The 2004 Touareg V10 TDI has a starting MSRP of $57,800.

Passat TDI The Volkswagen Passat has long been the most popular and most affordable German-built midsize family car sold in the U.S. The addition in 2004 of the Passat TDI sedan and wagon is sure to expand its significance even more.

The 2.0-liter TDI engine in the front-wheel-drive Passat incorporates the new unit injector technology found in the Touareg V10 TDI. The sophisticated four-cylinder, Motronic™ sequential multi-point direct-injection diesel engine with turbocharger and intercooler is enhanced by the Pumpe Düse technology and drive-by-wire fuel injection system. With a peak 134 hp at 4,000 rpm and maximum torque of 247 lbs. ft. at just 1,900 rpm, the 2.0-liter TDI engine mated to the standard-equipment five-speed automatic transmission moves both the Passat TDI sedan and wagon from 0-60 mph in just 10.4 seconds and to a top speed of 124 mph.

Volkswagen in Europe has proven just how clean high tech TDIs can get as the U.S. diesel fuel standards become more environmentally friendly. A particulate filter developed by Volkswagen for European applications may qualify the Passat TDI to meet 2007 U.S. EPA Tier 2, BIN 5 requirements as well as the California LEV II Program, Low Emission Vehicle (LEV) emission standards.

Using U.S. EPA fuel efficiency ratings of 38 mpg highway and 27 mpg city, the Passat TDI sedan and wagon have a best-in-class driving range. With a standard 16.4-gallon fuel tank, the range is 623 miles—enough to go from Detroit to Washington, D.C. on a single fill-up and still leave fuel in the tank for sight-seeing. Seating for five adults in up to 98 cu. ft. of passenger volume, plus 39 cu. ft. of cargo volume or up to 56.5 cu. ft. with the rear seats folded in the wagon, means plenty of friends and stuff can go along for the ride.

For smooth passage, standard equipment on the Passat TDI models includes a four-link front suspension and independent torsion beam rear axle suspension with coil springs, telescopic shock absorbers, and stabilizer bars front and back. Power-assisted rack-and-pinion steering and front vented and rear solid disc brakes with ABS, plus 15-in. wheels with all-season, snow chain-compatible tires are also standard equipment.

Amazingly, with all of this and its high-tech and fuel-efficient engine, the 2004 Passat 2.0L TDI sedan is priced at a MSRP of $23,060; the wagon at $24,060. Both prices represent a premium of just $205 over a comparable gasoline-engine model.

Volkswagen and Automotive Diesels The leader in direct injection diesel technology since 1996, Volkswagen cements its standing with TDI and the new Pumpe Düse unit injector technology, now available in the 2004 Volkswagen Touareg V10 TDI and Passat TDI sedan and wagon, as well as the Volkswagen New Beetle, Golf and Jetta models.