Overview

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 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 Mercedes Benz and rear in the case of the BMW). The first one has a Mercedes Benz-engineered powertrain under the hood, a 6-cylinder, 24-valves 272hp unit, while the other one gets its power and torque from a 8-cylinder, 32-valves 420hp engine designed by BMW.

Safety

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. 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? On the other hand, taking kerb weight as an important factor into account, 3 Series offers a marginal difference of 4% more metal.

Reliability

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. That's the official data, while our visitors describe reliability of Mercedes Benz with an average rating of 4.3, and models under the BMW badge with 4.1 out of 5. Independent research findings rank C 12% above average, and 3 Series 33% below the first one. Above it all, drivers of cars with the same engine as Mercedes Benz C rank it on average as 5.0, while the one under the competitor's bonnet gets 3.0 out of 5.

Performance & Fuel economy

BMW is undoubtly more agile, reaching 100km/h in 2 seconds less than its competitor. In addition to that it accelerates all the way to 250 kilometers per hour, exactly the same as the other car does. When it comes to fuel economy an obvious choice would be Mercedes Benz C, averaging around 10.2 liters of fuel per 100 kilometers (28 mpg), in combined cycle. That's 22% difference compared to 3 Series!

Verdict

Mercedes Benz is apparently more reliable, not too much, but just enough. 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. It all continues in the same direction, with BMW being considerably quicker, thus putting more smile on driver's face. It does come at a cost though, and that's the fuel consumption... All together, there's not much more to say, in this case I wouldn't even consider anything but Mercedes Benz. 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 thousands of similar, yet so different vehicles.