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 'Executive car' segment, the only major difference here really is their wheel drive configuration (front for the Audi and rear in the case of the Mercedes Benz). The first one has a Volkswagen-engineered powertrain under the hood, a 6-cylinder, 30-valves 193hp unit, while the other one gets its power and torque from a 6-cylinder, 18-valves 204hp 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, when it comes to weight, a factor that most people underestimate, Mercedes Benz S offers a considerable difference of 17% 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 Audi 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 A8 as average reliability-wise, and S is more or less at the same level.That apart, owners of different cars powered by the same engine as Audi A8 rank it on average as 4.9, while the one under the competitor's bonnet gets 3.0 out of 5.

Audi is undoubtly more agile, reaching 100km/h in 1.1 seconds less than its competitor. In addition to that it accelerates all the way to 236 kilometers per hour, 6km/h more than the other car. When it comes to fuel economy the winner has to be Audi A8, averaging around 9.9 liters of fuel per 100 kilometers (29 mpg), in combined cycle. We can't ignore that 16% difference compared to Mercedes Benz S.

Audi 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 significantly better overall protection, taking the lead here. From there things take a different direction, with Audi 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 Audi. 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 thousands of similar, yet so different vehicles.