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 4-cylinder, 16-valves 177hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 170hp 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 BMW 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 large family car segment, which is generally a good thing safety-wise, still it doesn't help us solve our dilemma, does it? On the other hand, if we'd like to consider vehicle mass in this context too, which we definitely should, Audi A4 offers a marginal difference of 3% more metal.

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, 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. The same official information place 3 Series as average reliability-wise, and A4 is more or less at the same level.That apart, owners of different cars powered by the same engine as 3 Series rank it on average as 3.7, while the one under the competitor's bonnet gets 4.2 out of 5.

BMW is a bit more agile, reaching 100km/h in 0.7 seconds less than its competitor. In addition to that it accelerates all the way to 230 kilometers per hour, 2km/h more than the other car. When it comes to fuel economy the winner has to be 3 Series, averaging around 4.8 liters of fuel per 100 kilometers (59 mpg), in combined cycle. We can't ignore that 21% difference compared to Audi A4.

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, 3 Series offers slightly better overall protection and takes the lead. It all continues in the same direction, with BMW offering somewhat better performance, just enough to call it quicker. To make things even better, it consumps less fuel! All together, there's not much more to say, in this case I wouldn't even consider anything but 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. 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 thousands of similar, yet so different vehicles.