Super Street Network

Due to the EU’s Global Data Protection Regulation, our website is currently unavailable to visitors from most European countries. We apologize for this inconvenience and encourage you to visit www.motortrend.com for the latest on new cars, car reviews and news, concept cars and auto show coverage, awards and much more.MOTORTREND.COM
 |   |   |  First Look: Audi A8 TDi
Subscribe to the Free
Newsletter

First Look: Audi A8 TDi

The age of the diesel really is upon us

Alistair Weaver
Jul 2, 2004
Photographer: Courtesy of Audi AG
0409_01z+Audi_A8_Tdi+Passenger_Side_View Photo 1/7   |   First Look: Audi A8 TDi

The history of the last 20 years has been filled with tipping points--the moments when one commodity gives place to another. In the music industry, the LP gave place to the cassette, which gave place to the CD, which will almost certainly give place to the MP3. And, in Europe at least, we may well be experiencing a tipping point in which petrol gives place to diesel power.

0409_02z+Audi_A8_Tdi+Passenger_Side_Taillight_View Photo 2/7   |   First Look: Audi A8 TDi

As little as two years ago, the case for diesel was still made on rational grounds--diesel cars used less fuel, which meant they were significantly cheaper to run. But with the advent of second-generation common rail technology, the decision to "go diesel" has become more emotive. In many instances, the diesel variant has become the most desirable car in the range, and this is certainly true of the Audi A8.

0409_03z+Audi_A8_Tdi+Front_Passenger_Side_View Photo 3/7   |   First Look: Audi A8 TDi

Audi's new 4.0-liter V8 is very probably the finest diesel engine on sale today, thanks to a technical specification that is the epitome of Vorsprung Durch Technik. Boasting four valves per cylinder and a second-generation common rail system with one rail per cylinder bank, it injects the fuel through seven-hole nozzles at an extraordinary pressure of 1600 bar. The system is also capable of injecting fuel several times per combustion cycle. Double pilot injection takes place at low engine speeds, single pilot injection in the medium speed range.

0409ec_a8audi04_z Photo 4/7   |   First Look: Audi A8 TDi

There are also two turbochargers, one for each bank of cylinders, and two air-to-air intercoolers. Both turbos boast variable geometry turbines, which means that the flow of exhaust gas to the turbine wheel can be optimized according to the load and engine speed. The maximum boost pressure is a surprisingly high 2.2 bar and everything is controlled by a Bosch EDC16 engine management system.

0409ec_a8audi05_z Photo 5/7   |   First Look: Audi A8 TDi

The net result of this technology-fest is an engine with the highest power and torque outputs of any production V8 turbodiesel. The maximum power is 272bhp at 3750 rpm and there's an astonishing 479 lb-ft of torque available from 1800 to 2500 rpm. This is supplied to the quattro four-wheel drive system via Audi's new six-speed tiptronic gearbox.

0409_06z+Audi_A8_Tdi+Interior_View_Dashboard Photo 6/7   |   First Look: Audi A8 TDi

Even at start-up, only a discerning ear will be able to tell that this is a diesel car. The traditional diesel clatter has been replaced with a low frequency hum. Pull away and this is replaced with a deep-throated burble that becomes a subtle growl on the application of full throttle. It may not sound quite as harmonic as Audi's petrol V8s, but it's by no means unpleasant, and at cruising speeds this engine is all but inaudible.

0409_07z+Audi_A8_Tdi+Front_Passenger_Side_View Photo 7/7   |   First Look: Audi A8 TDi

And this car is certainly rapid. Audi claims a 0-to-62-mph sprint of 6.7 sec. and an electronically governed top speed of 155 mph. But what these figures can't convey is the effortless mid-range urge--this engine is so smooth that the car gathers momentum almost by stealth. Give the throttle a determined prod, and the A8 settles on its haunches and muscles its way to a higher velocity. If we define a luxury car by its ability to offer instantaneous, effortless performance, then the A8 TDi must be one of the most luxurious cars on sale today.

The TDi also makes an ideal foil for the tiptronic gearbox. The "S" or sport mode is particularly effective. If the lateral acceleration sensor of the Electronic Stability Program (ESP) detects that the vehicle is cornering, the upshifts remain blocked until the end of the corner is reached. The gearbox also won't change up if the accelerator is suddenly released. In Audi-speak this system is known as Dynamic Shift Program, and in one fell swoop it has eradicated most of the frustrations associated with a traditional automatic gearbox.

The rest of the car reflects the A8's traditional virtues and vices. The handsome styling has considerable presence and exhibits none of the vulgarity that blights the BMW 7 Series. Audi is also capable of giving its German rivals a lesson in how to do interiors. The A8 cabin is not only more attractively styled than either the 7 Series or S-Class cockpits, but it is also constructed of higher-grade materials. It genuinely feels like an upmarket, boutique commodity.

The old A8 also exhibited many of these qualities, but it was badly let down by its dynamics. The latest A8 seeks to right this wrong with a sophisticated air-suspension system. It's a big improvement on its predecessor, but the ride and handling balance still lacks the ultimate comfort of the S-Class or the driving flair of the 7 Series. The difference, though, is marginal, and it's doubtful whether this will be a deciding factor in most luxury car purchases.

With a base price in the UK of #57,630 for the short wheelbase version, the TDi costs a little more than the 4.2 V8 (#55,055). The rational case for the TDi surrounds the fuel costs--it averages 29.4 mpg compared with the 4.2's 23.7 mpg--but it is even easier to make an argument for the diesel by describing its performance, refinement and sheer desirability. The age of the diesel really is upon us.

By Alistair Weaver
39 Articles

BROWSE CARS BY MARKET

MORE CARS

The G-Class has changed a lot since the 460-series debuted in 1979. Today, the G-wagon is now as much an S-Class as it is an off-roader
Bradley IgerFeb 15, 2019
You know very well the mere mention of JDM Legends will mean something crazy good is about to cross your path.
Jonathan WongFeb 13, 2019
The perfect balance of performance and practicality.
Bradley IgerFeb 8, 2019
We don't see many 3rd-gen Preludes at meets, shows, and track events, and when we do, they're nowhere near as aggressive as Satit Suwantong's
RodrezFeb 6, 2019
Big engine, little car; it's a formula that's worked wonders over multiple generations dating back to the earliest hot rod days.
RodrezFeb 5, 2019
Sponsored Links

SEARCH ARTICLES BY MAKE/MODEL

Search
CLOSE X
BUYER'S GUIDE
SEE THE ALL NEW
NEWS, REVIEWS & SPECS
TO TOP