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 4-cylinder, 16-valves 150hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 150hp engine designed by Volkswagen.

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 same number of safety stars gained in the process. Moving further on, let's take a closer look at some additional safety-related facts. Both vehicles belong to the luxury car segment, which is generally a very good thing safety-wise, but it doesn't do much to help us decide between the two. Furthermore, if we'd like to consider vehicle mass in this context too, which we definitely should, 5 Series offers a marginal difference of 1% 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. That's the official data, while our visitors describe reliability of BMW, as well as Audi, with the same average rating of 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.We should definitely mention that owners of cars with the same powertrain as 5 Series rank it on average as 3.0, while the one under the competitor's bonnet gets 4.6 out of 5.

Audi is a bit more agile, reaching 100km/h in 0.1 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 209 kilometers per hour, 1km/h less than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 4.6 liters of fuel per 100 kilometers (61 mpg), in combined cycle.

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, 5 Series offers slightly better overall protection and takes the lead. From there things take a different direction, with Audi offering somewhat better performance, just enough to call it quicker. To make things even better, it consumps less fuel! I believe that, when we take all into account, we have only one winner here - the Audi. 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.