Well, these are two pretty similar cars we have here! It's only details that could potentially make the difference. Considering they both belong to the large family car segment and utilize the same 4-door sedan body style and the 4 x 4 wheel drive system, it all comes up to the specific diesel engine choice they offer. The first one has a Volkswagen-engineered powertrain under the hood, a 6-cylinder, 24-valves 150hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 184hp 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 BMW being a slightly better choice apparently. Moving further on, let's take a closer look at some additional safety-related facts. 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. On the other hand, taking kerb weight as an important factor into account, 3 Series offers a considerable difference of 10% 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. 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. Independent research findings rank A4 as average reliability-wise, and 3 Series is more or less at the same level.We should definitely mention that owners of cars with the same powertrain as Audi A4 rank it on average as 2.3, while the one under the competitor's bonnet gets 5.0 out of 5.

BMW is a bit more agile, reaching 100km/h in 0.9 seconds less than its competitor. In addition to that it accelerates all the way to 224 kilometers per hour, 4km/h more than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 7.7 liters of fuel per 100 kilometers (37 mpg), in combined cycle.

BMW is apparently more reliable, not too much, but just enough. 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 beats the other contender by far, making it the best choice without even considering other things. It all continues in the same direction, with BMW being considerably quicker, thus putting more smile on driver's face. 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. 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 more than 12.000 different ones in our database.