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 150hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 140hp engine designed by Volkswagen.

Both vehicles got tested by European New Car Assessment Programme (Euro NCAP), with the same number of safety stars gained in the process. 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. On the other hand, taking kerb weight as an important factor into account, Audi A6 offers a marginal difference of 2% more metal.

I don't like generalizing things when it comes to reliability, although it does seem that both brands display similar results in faults and breakdowns, at least on all of the models level. These are the official statistics, while our visitors describe reliability of Mercedes Benz with an average rating of 4.4, and models under the Audi badge with 4.2 out of 5. Independent research findings rank E 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 Mercedes Benz E rank it on average as 4.9, 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 0.2 seconds less than its competitor. In addition to that it accelerates all the way to 216 kilometers per hour, 6km/h more than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 6.2 liters of fuel per 100 kilometers (46 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 offers slightly better overall protection and takes the lead. From there things take a different direction, with Mercedes Benz offering somewhat better performance, just enough to call it quicker. To make things even better, it consumps less fuel! No mistake, whatever you decide here, but I'd still go for the 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. 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.