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 'Large family car' segment, the only major difference here really is their wheel drive configuration (front for the Audi and rear in the case of the BMW). The first one has a Volkswagen-engineered powertrain under the hood, a 4-cylinder, 16-valves 143hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 143hp engine designed by BMW.

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 that fact doesn't break the tie between the two cars. Furthermore, if we'd like to consider vehicle mass in this context too, which we definitely should, Audi A4 offers a marginal difference of 4% 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, all the models observed together. That's the official data, while our visitors describe reliability of Audi with an average rating of 4.2, and models under the BMW badge with 4.1 out of 5. The same official information place A4 as average reliability-wise, and 3 Series is more or less at the same level.That apart, owners of different cars powered by the same engine as Audi A4 rank it on average as 4.3, while the one under the competitor's bonnet gets 4.1 out of 5.

BMW is a bit more agile, reaching 100km/h in 0.3 seconds less than its competitor. In addition to that it accelerates all the way to 210 kilometers per hour, 2km/h more 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, Audi A4 offers slightly better overall protection and takes the lead. From there things take a different direction, with BMW being considerably quicker, thus putting more smile on driver's face. 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 BMW. 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. 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.