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 4-door sedan body style within the same 'Large family car' segment, the only major difference here really is their wheel drive configuration (4 x 4 for the BMW and rear in the case of the Mercedes Benz). The first one has a BMW-engineered powertrain under the hood, a 4-cylinder, 16-valves 177hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 170hp 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. 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 that fact doesn't break the tie between the two cars. Furthermore, when it comes to weight, a factor that most people underestimate, 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, at least on all of the models level. These are the results of an independent reasearch, 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. Independent research findings rank 3 Series as average reliability-wise, and C is more or less at the same level.We should definitely mention that owners of cars with the same powertrain as 3 Series rank it on average as 3.7, while the one under the competitor's bonnet gets 4.6 out of 5.

BMW is a bit more agile, reaching 100km/h in 0.3 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 224 kilometers per hour, 5km/h less than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 5.7 liters of fuel per 100 kilometers (50 mpg), in combined cycle.

Mercedes Benz 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. No mistake, whatever you decide here, but I'd still go for 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. 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 thousands of similar, yet so different vehicles.