Overview

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 'Luxury car' segment, the only major difference here really is their wheel drive configuration (front for the BMW and 4 x 4 in the case of the Mercedes Benz). The first one has a BMW-engineered powertrain under the hood, a 6-cylinder, 24-valves 313hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 265hp engine designed by Mercedes Benz.

Safety

The fact that the BMW got tested by the European New Car Assessment Programme (Euro NCAP), while the other contender didn't, puts it sky-high safety-wise, in my eyes at least. Still, apart from the official crash test results there are other things we need to be aware of. Both vehicles belong to the luxury car segment, which is generally a very good thing safety-wise, still it doesn't help us solve our dilemma, does it? Furthermore, when it comes to weight, a factor that most people underestimate, 6 Series Gran Coupe offers a marginal difference of 1% more metal.

Reliability

Reliability is not the best thing to consider on the make level, but it is worth mentioning that both brands display similar results in faults and breakdowns, at least on all of the models level. 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. Above it all, drivers of cars with the same engine as 6 Series Gran Coupe rank it on average as 4.6, while the one under the competitor's bonnet gets 4.8 out of 5.

Performance & Fuel economy

BMW is undoubtly more agile, reaching 100km/h in 1 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 250 kilometers per hour, exactly the same as the other car does. When it comes to fuel economy the winner has to be 6 Series Gran Coupe, averaging around 5.4 liters of fuel per 100 kilometers (52 mpg), in combined cycle. We can't ignore that 24% difference compared to CLS.

Verdict

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, 6 Series Gran Coupe beats the other contender by far, making it the best choice without even considering other things. It all continues in the same direction, with BMW being considerably quicker, thus putting more smile on driver's face. To make things even better, it consumps less fuel! All together, there's not much more to say, in this case I wouldn't even consider anything but BMW. Anyway, that's the most objective conclusion I could've came up with and it's based solely on the information found on this website. Aspects such as design, practicality, brand value and driving experience are there for you to measure them out. I suggest you spend two more minutes in order to find out which car, based on your needs and budget, would be picked by the virtual adviser™, out of 12.000+ vehicles we currently have in our database.