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 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 BMW and 4 x 4 in the case of the Audi). The first one has a BMW-engineered powertrain under the hood, a 6-cylinder, 24-valves 218hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 225hp engine designed by Audi.

Both vehicles got tested by European New Car Assessment Programme (Euro NCAP), with the Audi being a slightly better choice apparently. 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, when it comes to weight, a factor that most people underestimate, Audi A6 offers a marginal difference of 9% 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 results of an independent reasearch, while our visitors describe reliability of BMW, as well as Audi, with the same average rating of 4.2 out of 5. Some independent research have also placed 5 Series as average reliability-wise, and A6 is more or less at the same level.We should definitely mention that owners of cars with the same powertrain as 5 Series rank it on average as 5.0 out of 5, exactly the same as the other one.

BMW is a bit more agile, reaching 100km/h in 0.1 seconds less than its competitor. In addition to that it accelerates all the way to 242 kilometers per hour, 2km/h more than the other car. When it comes to fuel economy the winner has to be 5 Series, averaging around 7.2 liters of fuel per 100 kilometers (39 mpg), in combined cycle. We can't ignore that 11% difference compared to Audi A6.

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. From there things take a different direction, with BMW 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 BMW. 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™, among thousands of similar, yet so different vehicles.