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 4-door sedan body style within the same 'Luxury car' segment, the only major difference here really is their wheel drive configuration (4 x 4 for the Audi and rear in the case of the BMW). The first one has a Volkswagen-engineered powertrain under the hood, a 10-cylinder, 40-valves 435hp unit, while the other one gets its power and torque from a 10-cylinder, 40-valves 507hp 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. 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, but that fact doesn't break the tie between the two cars. Furthermore, taking kerb weight as an important factor into account, Audi A6 offers a considerable difference of 10% 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, all the models observed together. These are the official statistics, while our visitors describe reliability of Audi with an average rating of 4.2, and models under the BMW badge with 4.1 out of 5. Independent research findings rank A6 as average reliability-wise, and 5 Series is more or less at the same level.We should definitely mention that owners of cars with the same powertrain as Audi A6 rank it on average as 4.0, while the one under the competitor's bonnet gets 1.0 out of 5.

BMW is a bit more agile, reaching 100km/h in 0.5 seconds less than its competitor. In addition to that it accelerates all the way to 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 13.4 liters of fuel per 100 kilometers (21 mpg), in combined cycle. We can't ignore that 10% difference compared to 5 Series.

Audi is apparently more reliable, not too much, but just enough. 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 BMW 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. Nevertheless, let's not forget that people have different preferences and needs, so what really counts is your personal feel. I'm only here to help. 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.