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 BMW-engineered powertrain under the hood, a 4-cylinder, 16-valves 184hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 170hp engine designed by Volkswagen.

The first thing to look into here would be the results from European New Car Assessment Programme (Euro NCAP) tests performed on the two cars. Good thing is that both vehicles got tested, 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, 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 4% more metal.

Manufacturers have been building their reliability reputation for decades now and, generally speaking, it appears 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 BMW, as well as Audi, with the same average rating of 4.2 out of 5. Some independent research have also placed 3 Series as average reliability-wise, and A4 is more or less at the same level.That apart, owners of different cars powered by the same engine as 3 Series rank it on average as 3.8, while the one under the competitor's bonnet gets 4.2 out of 5.

BMW is a bit more agile, reaching 100km/h in 0.4 seconds less than its competitor. In addition to that it accelerates all the way to 230 kilometers per hour, 2km/h more than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 5.5 liters of fuel per 100 kilometers (52 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, Audi A4 offers slightly better overall protection and takes the lead. From there things take a different direction, with BMW offering somewhat better performance, just enough to call it quicker. To make things even better, it consumps less fuel! It's really tough to make a final decision here, but if I'd need to, I'd say 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. 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™, out of 12.000+ vehicles we currently have in our database.