Two significantly similar cars, no doubt about that. Still, each one has something different to offer. Having both cars powered by diesel 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 Mercedes Benz). The first one has a BMW-engineered powertrain under the hood, a 4-cylinder, 16-valves 163hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 177hp engine designed by Mercedes Benz.

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, if we'd like to consider vehicle mass in this context too, which we definitely should, 3 Series offers a marginal difference of 1% 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, when all the models are taken into account. That's the official data, while our visitors describe reliability of BMW with an average rating of 4.1, and models under the Mercedes Benz badge with 4.3 out of 5. Unfortunatelly, I don't have enough insight that would allow me to comment in more details on the specific models level. That apart, owners of different cars powered by the same engine as 3 Series rank it on average as 4.7, while the one under the competitor's bonnet gets 3.0 out of 5.

Mercedes Benz 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 228 kilometers per hour, 6km/h more than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 4.4 liters of fuel per 100 kilometers (64 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 Mercedes Benz being considerably quicker, thus putting more smile on driver's face. To make things even better, it consumps less fuel! No mistake, whatever you decide here, but I'd still go for the Mercedes Benz. 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™, among more than 12.000 different ones in our database.