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 4-door sedan body style and the rear wheel drive system, it all comes up to the specific diesel engine choice they offer. The first one has a BMW-engineered powertrain under the hood, a 6-cylinder, 12-valves 143hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 197hp 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. Moving further on, let's take a closer look at some additional safety-related facts. 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, if we'd like to consider vehicle mass in this context too, which we definitely should, Mercedes Benz S offers a marginal difference of 5% 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. That's the official data, 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. Some independent research have also placed 7 Series as average reliability-wise, and S is more or less at the same level.We should definitely mention that owners of cars with the same powertrain as 7 Series rank it on average as 3.0, while the one under the competitor's bonnet gets 4.5 out of 5.

Mercedes Benz is way more agile, reaching 100km/h in 3 seconds less than its competitor. In addition to that it accelerates all the way to 228 kilometers per hour, 22km/h more than the other car. When it comes to fuel economy the winner has to be 7 Series, averaging around 8.2 liters of fuel per 100 kilometers (34 mpg), in combined cycle. We can't ignore that 9% difference compared to Mercedes Benz S.

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, Mercedes Benz S offers slightly better overall protection and takes the lead. It all continues in the same direction, with Mercedes Benz outracing its opponent in any situation possible, making it better choice for boy racers. It does come at a cost though, and that's the fuel consumption... It's really tough to make a final decision here, but if I'd need to, I'd say 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. 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.