Since its introduction in spring of 2013, Audi’s A8L TDI quattro has been generally received as a worthy alternative within the German automaker’s all-wheel-drive flagship line.

Why people have been keen on the diesel-burning A8L soon became apparent when we spent a week with an options-laden 2014 example stickering at $99,445.

The A8L TDI combines understated refinement, sharper handling than you’d imagine, and satisfying power. Its 36 mpg highway mileage also beats that of a four-cylinder Honda Accord, and is better than some would say a 4,600-pound quasi-limousine has any right to.

Available only in long-wheelbase form, the A8L is a refined example of the German carmaker’s art – even as Tesla’s Model S is making a play at getting upscale shoppers to eschew petroleum altogether.

In exchange for not having to find a public charger, and double-to-triple the range, Audi’s aluminum-bodied executive express is particularly well suited to long-distance drivers, offering a rarified experience of its own, albeit while still burning fuel.

It compares more closely – and well – to also-fuel-burning Mercedes-Benz S400 Hybrid, Lexus LS 600h, and Mercedes-Benz S350 BlueTec diesel.

These make a nod to fuel economy and emissions savings but not at the expense of comfort, performance, style, and prestige on par with their stable mates.

Audi has also developed a hybrid A8 but it was never released in the U.S.


Here to make a point and transplant some of Europe’s “clean diesel” market stateside, the A8L TDI easily outsells the two M-Bs plus the Lexus-hybrid combined.

We know some will argue fuel economy concerns are an afterthought for buyers of a car in this class. In some instances this is true, but it’s becoming less often the case.

If you’re thinking about the diesel A8, you may want to know if there’s a catch. Does the TDI come short from what you get in a gas version?

In some minor respects, arguably, but not by much. Ultimately whether it’s the way to go will depend on your priorities.

Turbo Diesel Injection

Audi’s “Aluminum Space Frame” based A8 lineup has benefitted from mild upgrades since it was redesigned for its third generation on Volkswagen’s MLB platform in 2009.

Mainly distinguishing the TDI – which starts at $82,500 – is what’s under the hood.


We’ve written at length about diesel’s potential in America, and whether diesel engines are really “clean” – the short answer is they must pass the same emission standards gas counterparts do, and diesel engines are the most thermally efficient.

The is one of four new TDI variants Audi announced in late 2012 would be introduced stateside.

In this case, the 3.0-liter V6 turbo diesel churns a respectable 240 horsepower at 3,550 rpm and 406 pounds-feet of torque at 1,750 rpm. It’s mainly the torque that authoritatively propels the 4,564-pound car to 60 mph in an Audi-estimated 6.4 seconds.

Independent tests have seen the TDI hit 60 in 5.9 seconds, the quarter mile in 14.4 in the mid 90s, and top speed is limited to 130 mph as with the other A8s.


This is a little slower than 5.5 seconds for the $78,800 supercharged A8L 3.0T V6. It’s also down from the 4.8 second, $87,600 biturbo 4.0 TFSI V8, and much less than the $135,000, 4.4-second 6.3-liter W12. And it’s really sluggish next to $112,500 4.0-liter S8 which hits 60 in 3.9 seconds and tops out at a limited 155 mph.

If part of owning this kind of car means you want to be able to blow away most challengers, or simply want deeper wells of power from which to draw, now’s your chance to forget the oil burner.

Audi is serious about promoting TDIs in America.

Audi is serious about promoting TDIs in America.

In its favor, its price point is low next to the fastest A8s. Further, its operation costs ought to be less and stops at the fuel station less frequent.

Drivability, noise, vibration, and harshness are acceptably smooth, if maybe not quite as buttery as A8s with higher cylinder counts.

Common to all A8s is Audi’s quattro always-operative all-wheel drive system and eight-speed transmission. The “Tiptronic” tranny can be manually shifted with paddles or left in automatic “D” or “S” mode.

The TDI’s 2.624:1 final drive ratio is taller than the 3.204:1 for the others mentioned – W12 gets 3.076:1.

Engine rpm for the TDI are generally as low as Farmer Brown’s tractor during normal driving, and on the freeway revs hovering below or a bit over 1,500 rpm help explain the high mpg rating.


At the same time, passing power is no worries from any speeds and this Autobahn-ready car feels planted anywhere.

Our East Coast testing was during February on dry and snowy roads and the car came with winter radials mounted to optional $1,200 20-inch wheels in place of the standard 19-inch 265/40 all-seasons.

This made it a superb snow driver assuming we weren’t carving new paths in high powder. Its ride height – especially with adjustable suspension set low, as pictured – provides only normal ground clearance.


The A8’s imposing “Singleframe” front grille and sheet metal bulges and curves proportioned just-right make this a sleek-looking car, especially in profile, front or rear three-quarter view, and head-on.

To save weight on a vehicle that has become more and more feature packed, Audi consulted with Alcoa years ago and was an early pioneer in aluminum craftsmanship.


Unfortunately, the trunk has only 13.2 cubic feet volume. It’s workable if you pack fairly light, and perhaps it’s small to save space everywhere else?

The classy but understated A8L TDI would be a good beater for Prince William – who’s been spotted in various Audi’s before. With it, he could comfortably troll around with three of his friends, even if all were 6-feet, 5-inches tall.

The A8L TDI comes standard with five extra inches of legroom on a 122.9-inch (3,122 mm) wheelbase. Front and back seats, as you’d imagine, are comfortable and supportive.

13.2-cubic-foot trunk is electrically opened and shut with remote or by pushbutton.

13.2-cubic-foot trunk is electrically opened and shut with remote or by pushbutton.

Back seat passengers are greeted with their own right/left climate controls, and DC power sources. Electrically retractable sun shades keep prying eyes out, and elbows can recline on a padded fold-down center rest with storage and retractable cup holders. Rear massage seats are optional.

There are more cushy sedans to be sure, but this Audi has a balance of sensible-and-richness in a gratifying blend well short of ostentatious, but in no wise cheap or plain.

Optional goodies on our press fleet loaner included a $6,300, 19-speaker, 1,400-watt Bang & Olufsen sounds system, $4,000 Premium package including the 22-way heated and cooled front seats with massage, new-for-2014 LED headlights, and a $1,300 large front and rear “panoramic” sunroof.

The stereo sounds great, but it’s better for classical or jazz and not heavy base-intensive genres where you want to really feel the beat.

Using the massage seats requires a slight learning curve as the Multi Media Interface (MMI) displays the various settings and power levels. The massager is comfortable, did not distract us or make anyone want to fall asleep at the wheel, and was a hit with everyone who sampled them.

If we had gotten too cozy and veered off course, lane assist is one of a few safety nannies there to try and keep you on track even if distracted by all the gadgets.


The MMI with handwriting recognition technology is otherwise a terrific interface. Its 8-inch screen is not a touch screen, and smaller than the 12-incher in a Mercedes S-class, or the 17-inch touch screen in a Tesla Model S.

Speaking of which, the Tesla’s interior layout is a huge contrast with its utter simplicity and large bare cubby space between front-seat passengers.

The big Audi has a traditional sporty/luxurious feel with arrayed gauges, buttons, and knobs, and the center console makes you feel more encased, but not claustrophobic.

Audi infotainment is of course comprehensive, including 3G WiFi, Bluetooth, and various devices, plus its navigation system uses Google Earth to show the aerial view of the car in real time.

This is pretty far-out technology; cars you park next to are live on your viewing screen, as are painted parking spot lines.

This is part of “Audi Connect” which comes activated for six months and may be kept active starting at $15 per month.


The TDI shares with the other A8s a five-link front suspension with stabilizer bar, and trapezoidal-link rear suspension.

Pitch it into a hard bend, and it’s balanced, reassuring, and encourages you to try for a bit more – but not too much more.

Body roll under hard corning, while present, is fairly well controlled, and while you’d not normally think a car this massive could be called “athletic,” in qualified terms, it is.

The transmission can be manually over-ridden by the paddle shifters in either D or S and upshifts are crisp and acceptably quick. Downshifts are delayed however, and you’d not mistake yourself as being in a Porsche Panamera with its snappy track-worthy, rev-matching PDK transmission.

Otherwise, the sound track from this 4,500-rpm redlining TDI does not remind you of a clattery diesel but of smooth, muted power similar in note to a gas engine.

Stand outside or open the hood, and diesel sound – open-hood sound played briefly at video’s end – is more apparent, but there’s no black exhaust smoke or diesel smell to speak of.

Braking action is powerful from the 14-inch front, 13-inch rear vented discs that haul it down in near-record time – really. This car with the standard tires has been measured from 60-0 stops in 109 feet.


At parking lot speeds however, the A8L’s steering feels unnecessarily heavy and could use more power assist. As speeds increase effort becomes normal.

Obviously, while it’s generally satisfying, the A8L TDI is no short-wheelbase S8, let alone able to perform like a mid-sized sports sedan.

Being big, heavy, and capable of hurtling that weight pretty impressively, we’d call it nicely balanced in cornering and braking – as really it should be.

As a bonus, we averaged between 28 and 33 mpg in various mixed runs and did see the rated mpg or better on the highway.

With its low 0.26 coefficient of drag, the A8L TDI can deliver its 36 rated highway mpg, especially with cruise control on, and range can thus be stretched to over 800 miles under such conditions.

Worth It?

We really like this Audi, but as the environmentally conscious will note, it does little to reduce petroleum dependence.

True that, but the same could be said of the mid-sized Toyota Avalon Hybrid which is rated at only 3 mpg better on the highway (albeit with 40 mpg city and combined).


Compared to actual competitors’ mpg, this TDI beats every one except the loosely comparable Tesla Model S which uses no gas.

But it’s the sum-total experience people are after at this level, so let’s objectively look at this for a minute.

Even some Model S owners have reported they chose Tesla’s trendy new car because it’s technologically cool, fast, and good looking. Some are buying it because it represents a new EV paradigm, or it simply offers green credibility in some circles, but for others, ecology and reducing petroleum dependence are not primary considerations.

What does the market say? Feb. 2014 unit sales: Audi - 59, Lexus hybrid - 11; M-B diesel - 6; M-B hybrid - 2; Tesla EV - est. 1,400.

What does the market say? Feb. 2014 unit sales: Audi – 59, Lexus hybrid – 11; M-B diesel – 6; M-B hybrid – 2; Tesla EV – est. 1,400.

And if you do drive a Model S hard, it wastes electrons, and those MPGe scores plummet, as does the advertised range.

The Audi can go where there may be no EV infrastructure, refuels in three minutes, and some people simply want what this car offers, like it or not.

This is not to make an outright value judgment of the TDI over the Model S, or vice versa, because they are apples and oranges. But in one sense, they’re not. The reality is people buy luxury cars for all they can do for them.


If it is purely all about frugal living and nothing else, our advice is buy a Prius or Volt and save a ton of cash.

In the Audi’s favor is it uses relatively less fuel and its ride, styling, performance, and handling round out the package.

Not helping things is that diesel fuel can be pricey for a car commanding a $3,700 premium over the comparable A8L 3.0-liter V6 gas model, but at this level, the MSRP difference is not substantial.

All things considered, Audi’s beautiful A8L TDI makes a compelling case against any fuel burner in its class.