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 258hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 272hp engine designed by Audi.

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. 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, still it doesn't help us solve our dilemma, does it? On the other hand, if we'd like to consider vehicle mass in this context too, which we definitely should, Audi A6 offers a marginal difference of 4% 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 BMW with an average rating of 4.1, and models under the Audi badge with 4.2 out of 5. Independent research findings rank 5 Series 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 5 Series rank it on average as 4.8, while the one under the competitor's bonnet gets 5.0 out of 5.

Audi 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, 3km/h more than the other car. When it comes to fuel economy the winner has to be Audi A6, averaging around 5.3 liters of fuel per 100 kilometers (53 mpg), in combined cycle. We can't ignore that 11% difference compared to 5 Series.

Audi 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. It all continues in the same direction, with Audi 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 Audi. Anyway, that's the most objective conclusion I could've came up with and it's based solely on the information found on this website. Aspects such as design, practicality, brand value and driving experience are there for you to measure them out. I suggest you spend two more minutes in order to find out which car, based on your needs and budget, would be picked by the virtual adviser™, among thousands of similar, yet so different vehicles.