Two significantly similar cars, no doubt about that. Still, each one has something different to offer. Having both cars powered by petrol engines and utilizing the 5-door wagon body style within the same 'Luxury car' segment, the only major difference here really is their wheel drive configuration (rear for the Mercedes Benz and 4 x 4 in the case of the Audi). The first one has a Mercedes Benz-engineered powertrain under the hood, a 8-cylinder, 32-valves 408hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 333hp 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. Still, apart from the official crash test results there are other things we need to be aware of. 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, when it comes to weight, a factor that most people underestimate, CLS offers a marginal difference of 8% 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, all the models observed together. These are the official statistics, 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. The same official information place CLS as average reliability-wise, and A6 is more or less at the same level.Above it all, drivers of cars with the same engine as CLS rank it on average as 3.0, while the one under the competitor's bonnet gets 4.3 out of 5.

Mercedes Benz is a bit more agile, reaching 100km/h in 0.4 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 250 kilometers per hour, exactly the same as the other car does. When it comes to fuel economy the winner has to be Audi A6, averaging around 7.6 liters of fuel per 100 kilometers (37 mpg), in combined cycle. We can't ignore that 16% difference compared to CLS.

Audi 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. From there things take a different direction, with Mercedes Benz offering somewhat better performance, just enough to call it quicker. It does come at a cost though, and that's the fuel consumption... 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. Also, you could use the oportunity to find out which car, everything taken into account, would be the perfect choice for you in the eyes of the virtual adviser™, out of 12.000+ vehicles we currently have in our database.