Two significantly similar cars, no doubt about that. Still, each one has something different to offer. Having both cars powered by petrol 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 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 218hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 200hp engine designed by Volkswagen.

Both vehicles got tested by European New Car Assessment Programme (Euro NCAP), with the BMW being a slightly better choice apparently. 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, still it doesn't help us solve our dilemma, does it? On the other hand, taking kerb weight as an important factor into account, Audi A4 offers a marginal difference of 6% 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, at least on all of the models level. That's the official data, while our visitors describe reliability of BMW, as well as Audi, with the same average rating of 4.2 out of 5. Independent research findings rank 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 3.8, while the one under the competitor's bonnet gets 4.4 out of 5.

BMW is a bit more agile, reaching 100km/h in 0.2 seconds less than its competitor. In addition to that it accelerates all the way to 245 kilometers per hour, 7km/h more than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 8.6 liters of fuel per 100 kilometers (33 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, 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! It's not difficult to say then that if I'd need to make a choice, it would definitely be 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.