Well, these are two pretty similar cars we have here! It's only details that could potentially make the difference. Considering they both belong to the luxury car segment and utilize the same 4-door sedan body style and the 4 x 4 wheel drive system, it all comes up to the specific diesel engine choice they offer. The first one has a BMW-engineered powertrain under the hood, a 6-cylinder, 24-valves 231hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 233hp engine designed by Audi.

The first thing to look into here would be the results from European New Car Assessment Programme (Euro NCAP) tests performed on the two cars. Good thing is that both vehicles got tested, 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 7% 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 official statistics, 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 5.0, while the one under the competitor's bonnet gets 4.6 out of 5.

BMW is a bit more agile, reaching 100km/h in 0.3 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 242 kilometers per hour, 5km/h less than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 7.8 liters of fuel per 100 kilometers (36 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. 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. 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™, out of 12.000+ vehicles we currently have in our database.