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 2-door cabriolet body style within the same 'Sports 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 8-cylinder, 32-valves 450hp unit, while the other one gets its power and torque from a 8-cylinder, 32-valves 435hp engine designed by Mercedes Benz.

Unfortunatelly, neither of the two vehicles was submitted to the European New Car Assessment Programme (Euro NCAP) testing. This makes it virtually impossible for me to pick one over the other and I'm generally against buying such cars as the safety should really always come first. Still, apart from the official crash test results there are other things we need to be aware of. Both vehicles belong to the sports car segment, which is generally classifying them somewhere in the middle 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 offers a considerable difference of 16% 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, at least on all of the models level. These are the official statistics, while our visitors describe reliability of BMW with an average rating of 4.2, and models under the Mercedes Benz badge with 4.4 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 rank it on average as 5.0, while the one under the competitor's bonnet gets 3.0 out of 5.

BMW is a bit more agile, reaching 100km/h in 0.1 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 things look pretty much the same for both cars, averaging around 9.2 liters of fuel per 100 kilometers (31 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, 6 Series offers significantly better overall protection, taking the lead here. It all continues in the same direction, with BMW offering somewhat better performance, just enough to call it quicker. It does come at a cost though, and that's the fuel consumption... No mistake, whatever you decide here, but I'd still go for the BMW. 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. 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.