Two significantly similar cars, no doubt about that. Still, each one has something different to offer. Having both cars powered by petrol engines and utilizing the 5-door wagon body style within the same 'Large family car' segment, the only major difference here really is their wheel drive configuration (rear for the BMW and front in the case of the Audi). 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 190hp engine designed by Volkswagen.

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, but it doesn't do much to help us decide between the two. Furthermore, taking kerb weight as an important factor into account, 3 Series offers a marginal difference of 1% 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, all the models observed together. That's the official data, while our visitors describe reliability of BMW with an average rating of 4.1, and models under the Audi badge with 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.Above it all, drivers of cars with the same engine as 3 Series rank it on average as 3.5, while the one under the competitor's bonnet gets 2.5 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 237 kilometers per hour, 7km/h more than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 6.2 liters of fuel per 100 kilometers (46 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. From there things take a different direction, with Audi offering somewhat better performance, just enough to call it quicker. To make things even better, it consumps less fuel! No mistake, whatever you decide here, but I'd still go for the Audi. 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™, among more than 12.000 different ones in our database.