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 180hp 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 same number of safety stars gained in the process. Still, apart from the official crash test results there are other things we need to be aware of. 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, if we'd like to consider vehicle mass in this context too, which we definitely should, 3 Series offers a marginal difference of 2% 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, when all the models are taken into account. These are the results of an independent reasearch, 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 3.5, while the one under the competitor's bonnet gets 5.0 out of 5.

BMW is a bit more agile, reaching 100km/h in 0.1 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 224 kilometers per hour, 1km/h less 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 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. When it comes to performance, both vehicles provide similar experience, so I wouldn't point any of them out. 3 Series still consumps less fuel, which needs to be taken into consideration. It's not difficult to say then that if I'd need to make a choice, it would definitely be the BMW. 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. I suggest you spend two more minutes in order to find out which car, based on your needs and budget, would be picked by the virtual adviser™, out of 12.000+ vehicles we currently have in our database.