Two significantly similar cars, no doubt about that. Still, each one has something different to offer. Having both cars powered by diesel engines and utilizing the 4-door sedan 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 front in the case of the Audi). The first one has a Mercedes Benz-engineered powertrain under the hood, a 4-cylinder, 16-valves 160hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 163hp engine designed by Volkswagen.

A starting point here would be to take a look at the results from European New Car Assessment Programme (Euro NCAP) tests which were performed on both of the cars, with the same number of safety stars gained in the process. 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, still it doesn't help us solve our dilemma, does it? On the other hand, taking kerb weight as an important factor into account, Audi A6 offers a marginal difference of 3% more metal.

Manufacturers have been building their reliability reputation for decades now and, generally speaking, it appears that both brands display similar results in faults and breakdowns, all the models observed together. That's the official data, 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. Unfortunatelly, I don't have enough insight that would allow me to comment in more details on the specific models level. That apart, owners of different cars powered by the same engine as Mercedes Benz E rank it on average as 5.0, while the one under the competitor's bonnet gets 3.0 out of 5.

Mercedes Benz is a bit more agile, reaching 100km/h in 0.8 seconds less than its competitor. In addition to that it accelerates all the way to 226 kilometers per hour, 2km/h more than the other car. When it comes to fuel economy the winner has to be Mercedes Benz E, averaging around 4.7 liters of fuel per 100 kilometers (60 mpg), in combined cycle. We can't ignore that 30% difference compared to Audi A6.

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 offers slightly better overall protection and takes the lead. From there things take a different direction, with Mercedes Benz being considerably quicker, thus putting more smile on driver's face. To make things even better, it consumps less fuel! All together, there's not much more to say, in this case I wouldn't even consider anything but Mercedes Benz. 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™, among thousands of similar, yet so different vehicles.