Well, these are two pretty similar cars we have here! It's only details that could potentially make the difference. Considering they both belong to the luxury car segment and utilize the same 5-door wagon body style and the 4 x 4 wheel drive system, it all comes up to the specific diesel engine choice they offer. The first one has a Mercedes Benz-engineered powertrain under the hood, a 4-cylinder, 16-valves 204hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 190hp engine designed by Volkswagen.

The fact that the Audi got tested by the European New Car Assessment Programme (Euro NCAP), while the other contender didn't, puts it sky-high safety-wise, in my eyes at least. That aside, let's consider some other aspects which affect safety. Both vehicles belong to the luxury car segment, which is generally a very good thing safety-wise, but it doesn't do much to help us decide between the two. Furthermore, taking kerb weight as an important factor into account, CLS offers a marginal difference of 4% more metal.

Reliability is not the best thing to consider on the make level, but it is worth mentioning that both brands display similar results in faults and breakdowns, at least on all of the models level. These are the results of an independent reasearch, while our visitors describe reliability of Mercedes Benz with an average rating of 4.3, and models under the Audi badge with 4.2 out of 5. Independent research findings rank CLS as average reliability-wise, and A6 is more or less at the same level.That apart, owners of different cars powered by the same engine as CLS rank it on average as 4.8, while the one under the competitor's bonnet gets 3.7 out of 5.

Audi is a bit more agile, reaching 100km/h in 0.2 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 224 kilometers per hour, 5km/h less than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 5.3 liters of fuel per 100 kilometers (53 mpg), in combined cycle.

Mercedes Benz appears just a bit more reliable, although the difference is truly marginal. The most important thing when deciding between any two vehicles should always be safety, both passive and active. In my opinion, everything taken into account, Audi A6 beats the other contender by far, making it the best choice without even considering other things. When it comes to performance, both vehicles provide similar experience, so I wouldn't point any of them out. Audi A6 still consumps less fuel, which needs to be taken into consideration. All together, there's not much more to say, in this case I wouldn't even consider anything but Audi. In any case that's my personal view, built upon all the data available to me. What should decide here though is the way you feel about the two vehicles, and I hope you'll find my guidelines useful in the process. In case you have two minutes to spare I invite you to define your needs, desires and budget and see which car would be chosen by the virtual adviser™, out of 12.000+ vehicles we currently have in our database.