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

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 that fact doesn't break the tie between the two cars. On the other hand, when it comes to weight, a factor that most people underestimate, Audi A6 offers a marginal difference of 3% 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 23% below average, and A6 20% below the first one. We should definitely mention that owners of cars with the same powertrain as 5 Series rank it on average as 5.0, while the one under the competitor's bonnet gets 4.3 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 225 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 7.1 liters of fuel per 100 kilometers (40 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. At the end, as much as I'd like to give you a winner here, it's simply a pure tie if you ask me. 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. In case you have two minutes to spare I invite you to define your needs, desires and budget and see which car would be chosen by the virtual adviser™, among more than 12.000 different ones in our database.