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 4-door sedan body style within the same 'Large family 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 184hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 180hp engine designed by Volkswagen.

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. That aside, let's consider some other aspects which affect safety. Both vehicles belong to the large family car segment, which is generally a good thing safety-wise, but it doesn't do much to help us decide between the two.

Reliability is not the best thing to consider on the make level, but it is worth mentioning that both brands display similar results in faults and breakdowns, all the models observed together. These are the results of an independent reasearch, while our visitors describe reliability of BMW, as well as Audi, with the same average rating of 4.2 out of 5. The same official information place 3 Series as average reliability-wise, and A4 is more or less at the same level.We should definitely mention that owners of cars with the same powertrain as 3 Series rank it on average as 5.0, while the one under the competitor's bonnet gets 3.5 out of 5.

There's not enough data for me to elaborate on the subject, I'm affraid.

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 this case though, it seems that both cars show similar levels of passenger protection all together, so that won't break a tie. When it comes to performance, both vehicles provide similar experience, so I wouldn't point any of them out. Fuel consumption is more or less the same. It's really tough to make a final decision here, but if I'd need to, I'd say BMW. 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™, out of 12.000+ vehicles we currently have in our database.