Audi’s Latest Generation Clean Diesel Engine Shatters Old Perceptions

Maybe you’ve seen or heard an old 1980’s era car powered by diesel fuel rumbling by on the street from time to time. Probably the first thing that came to mind was how loud the engine was. The second thing that came to mind probably was how bad the exhaust fumes smelled. With the release of the 2014 A6, A7, and Q5 TDI models, Audi has shattered all the negative perceptions of diesel powered cars and then some.

Audi recently invited a group of journalists, Audi Club of North America members, and researchers to Washington, D.C. to test drive the 2014 A6 TDI, A7 TDI, and Q5 TDI around the scenic backcountry roads of Virginia and Maryland. Adding a little gamification to your typical test drive, Audi officials wanted to see which pair of drivers could score the highest fuel efficiency for each model we drove.

Before we get to the results of Audi’s efficiency drive, here are some basic facts about the TDI engine:

• The engine: 3.0-liter V6 producing 240 horsepower and a whopping 428 pound-feet of torque

• Transmission: 8 speed automatic

• Fuel Economy: 24 mpg city/38 mpg highway (A6 TDI and A7 TDI) and 24 mpg city/31 mpg highway (Q5 TDI).

This latest generation of diesel engines was also designed to meet ULEV II emissions requirements, meaning these engines are really clean. Audi engineers reduced NOx emissions just by keeping the fuel at the right temperature. Additionally, through a 3 step process which includes an oxidation catalyst, diesel trap, and SCR catalyst, remaining NOx is captured. Gone are the days where diesels smelled and polluted our garages and streets. Audi engineers also shaved 55 pounds off the weight of engine. With respect to fuel economy, Audi claims the A6 TDI can travel up to 700 miles on one tank. Of course actual results may vary.

On the day of the test drive, the weather was not entirely cooperative. Starting with overcast skies in Washington, D.C., rain started to fall in late morning and continued throughout the afternoon. While not ideal weather, Audi’s legendary Quattro system came in handy on more than one occasion. Although the point of the test drive program was to see which pair of drivers would score the highest fuel efficiency for each model, it was readily apparent that amongst a certain group of drivers, it was clearly a race to the bottom. After all, these are Audi’s and they are performance luxury vehicles.

I, along with my driving partner had an average of 31.4 mpg after driving all three models over a total span of 313 miles (We drove these cars harder than normal and still were above 30 mpg). This is fantastic for vehicles in this sector as far as I am concerned. Others fared much better. For instance, one pair hit a remarkable 41.5 mpg with an average speed of 38.7 mph in the A6 TDI and had an overall average of 38.7 mpg across all three cars (That beats EPA estimates!). If you think the other drivers were hypermiling, think again: They hit 41.5 mpg with an average speed of 38.7 mph while I and my partner in crime hit 33.1 mpg with an average speed of 38.9 mph.

During the drive, there was more than enough power to whisk the cars by others on the road. On more than one occasion, when we accelerated hard, the smile on my face could not be contained as I was seated snugly in the beautiful interior of the cars. The cars were responsive and handled extremely well. With this test drive, Audi has proven that fuel efficiency does not have to come at the expense of performance, responsiveness and the all important fun factor. But for the fact that the fleet of cars we were driving had “Audi TDI” plastered on the driver and passenger sides, you would not otherwise know that you were driving a clean diesel vehicle.

The latest generation of Audi clean diesels makes a clear case for drivers who don’t want to sacrifice. When factoring in the total cost of ownership of clean diesels compared to their gas counterparts, the case for a clean diesel vehicles is reinforced. According to a University of Michigan Transportation Research Institute study, the total cost of ownership of passenger vehicles equipped with clean diesel engines was significantly less than their gas powered counterpart, in some instances by as much as $5,475 over 5 years/75,000 miles.

Old perceptions of diesel powered cars should be put to bed. Audi’s 2nd generation TDI vehicles have clearly shattered any perceptions I’ve had about diesels, especially since I have been driving a 1982 Mercedes-Benz 240D most of the summer. With the release of the 2014 TDI’s, Audi is sending a signal to the market that you don’t have to make any compromises with a clean diesel. I’m convinced. You should be too.

Walter Wang is Managing Editor of CleanTechies. Follow Walter on Twitter: @energytaxprof