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 Audi-engineered powertrain under the hood, a 6-cylinder, 24-valves 272hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 258hp 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, still it doesn't help us solve our dilemma, does it? Furthermore, when it comes to weight, a factor that most people underestimate, Audi A4 offers a marginal difference of 7% 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. 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.That apart, owners of different cars powered by the same engine as Audi A4 rank it on average as 5.0, while the one under the competitor's bonnet gets 4.8 out of 5.

Both of the cars accelerate exactly the same, so we couldn't put one above the other. Car No. 2 is faster though, reaching top speed of 250 kilometers per hour, 1km/h more than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 5.3 liters of fuel per 100 kilometers (54 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, Audi A4 offers slightly better overall protection and takes the lead. When it comes to performance, both vehicles provide similar experience, so I wouldn't point any of them out. Audi A4 still consumps less fuel, which needs to be taken into consideration. I believe that, when we take all into account, we have only one winner here - the Audi. Nevertheless, let's not forget that people have different preferences and needs, so what really counts is your personal feel. I'm only here to help. 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.