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 (front for the Audi and rear in the case of the BMW). The first one has a Volkswagen-engineered powertrain under the hood, a 6-cylinder, 24-valves 180hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 177hp engine designed by BMW.

Both vehicles got tested by European New Car Assessment Programme (Euro NCAP), with the Audi being a slightly better choice apparently. 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, taking kerb weight as an important factor into account, Audi A6 offers a marginal difference of 4% 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, when all the models are taken into account. These are the results of an independent reasearch, while our visitors describe reliability of Audi, as well as BMW, with the same average rating of 4.2 out of 5. Some independent research have also placed A6 as average reliability-wise, and 5 Series is more or less at the same level.That apart, owners of different cars powered by the same engine as Audi A6 rank it on average as 4.3, while the one under the competitor's bonnet gets 5.0 out of 5.

Both of the cars accelerate exactly the same, so we couldn't put one above the other. Car No. 1 reaches top speed of 230 kilometers per hour, exactly the same as the other car does. When it comes to fuel economy things look pretty much the same for both cars, averaging around 6.9 liters of fuel per 100 kilometers (41 mpg), in combined cycle.

BMW 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 much better overall protection, which launches it ahead of the other contender. When it comes to performance, both vehicles provide similar experience, so I wouldn't point any of them out. 5 Series still consumps less fuel, which needs to be taken into consideration. It's really tough to make a final decision here, but if I'd need to, I'd say 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.