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 6-cylinder, 24-valves 155hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 184hp engine designed by BMW.

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. 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. On the other hand, taking kerb weight as an important factor into account, 3 Series offers a marginal difference of 4% 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. These are the official statistics, while our visitors describe reliability of Audi, as well as BMW, with the same average rating of 4.2 out of 5. Independent research findings rank A4 as average reliability-wise, and 3 Series is more or less at the same level.Above it all, drivers of cars with the same engine as Audi A4 rank it on average as 4.0, while the one under the competitor's bonnet gets 5.0 out of 5.

BMW is undoubtly more agile, reaching 100km/h in 1.7 seconds less than its competitor. In addition to that it accelerates all the way to 225 kilometers per hour, 6km/h more than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 7 liters of fuel per 100 kilometers (40 mpg), in combined cycle.

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 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 being considerably quicker, thus putting more smile on driver's face. Fuel consumption is more or less the same. 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™, out of 12.000+ vehicles we currently have in our database.