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 2-door coupe body style within the same 'Sports 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 286hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 240hp engine designed by Audi.

Unfortunatelly, neither of the two vehicles was submitted to the European New Car Assessment Programme (Euro NCAP) testing. This makes it virtually impossible for me to pick one over the other and I'm generally against buying such cars as the safety should really always come first. That aside, let's consider some other aspects which affect safety. Both vehicles belong to the sports car segment, which is generally classifying them somewhere in the middle 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, 6 Series offers a marginal difference of 1% 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, at least on all of the models level. These are the official statistics, while our visitors describe reliability of BMW, as well as Audi, with the same average rating of 4.2 out of 5. Unfortunatelly, I don't have enough insight that would allow me to comment in more details on the specific models level. We should definitely mention that owners of cars with the same powertrain as 6 Series rank it on average as 4.0, while the one under the competitor's bonnet gets 5.0 out of 5.

Audi is a bit more agile, reaching 100km/h in 0.4 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 things look pretty much the same for both cars, averaging around 6.8 liters of fuel per 100 kilometers (42 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, 6 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! No mistake, whatever you decide here, but I'd still go for the 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. 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.