Well, these are two pretty similar cars we have here! It's only details that could potentially make the difference. Considering they both belong to the executive car segment and utilize the same 2-door coupe body style and the 4 x 4 wheel drive system, it all comes up to the specific petrol engine choice they offer. The first one has a BMW-engineered powertrain under the hood, a 6-cylinder, 24-valves 340hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 367hp 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 executive car segment, which is generally a fortune safety-wise, but that fact doesn't break the tie between the two cars. On the other hand, taking kerb weight as an important factor into account, Mercedes Benz S offers a marginal difference of 7% more metal.

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, when all the models are taken into account. These are the results of an independent reasearch, 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. That apart, owners of different cars powered by the same engine as 8 Series rank it on average as 3.0, while the one under the competitor's bonnet gets 1.0 out of 5.

BMW is a bit more agile, reaching 100km/h in 0.8 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 250 kilometers per hour, 5km/h less than the other car. When it comes to fuel economy the winner has to be 8 Series, averaging around 7.5 liters of fuel per 100 kilometers (38 mpg), in combined cycle. We can't ignore that 19% difference compared to Mercedes Benz S.

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, Mercedes Benz S offers slightly better overall protection and takes the lead. From there things take a different direction, with BMW offering somewhat better performance, just enough to call it quicker. 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. 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 more than 12.000 different ones in our database.