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 5-door wagon 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 BMW-engineered powertrain under the hood, a 6-cylinder, 24-valves 313hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 245hp engine designed by Audi.

Both vehicles got tested by European New Car Assessment Programme (Euro NCAP), with the same number of safety stars gained in the process. 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, Audi A4 offers a marginal difference of 3% 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. The same official information place 3 Series as average reliability-wise, and A4 is more or less at the same level.Above it all, drivers of cars with the same engine as 3 Series rank it on average as 4.6, while the one under the competitor's bonnet gets 4.7 out of 5.

BMW is undoubtly more agile, reaching 100km/h in 1.3 seconds less than its competitor. In addition to that it accelerates all the way to 250 kilometers per hour, 10km/h more than the other car. When it comes to fuel economy the winner has to be 3 Series, averaging around 5.3 liters of fuel per 100 kilometers (53 mpg), in combined cycle. We can't ignore that 17% 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, 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! 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. Also, you could use the oportunity to find out which car, everything taken into account, would be the perfect choice for you in the eyes of the virtual adviser™, among thousands of similar, yet so different vehicles.