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 4 x 4 wheel drive system, it all comes up to the specific petrol engine choice they offer. The first one has a Mercedes Benz-engineered powertrain under the hood, a 8-cylinder, 32-valves 340hp unit, while the other one gets its power and torque from a 8-cylinder, 32-valves 372hp engine designed by Volkswagen.

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, still it doesn't help us solve our dilemma, does it? Furthermore, taking kerb weight as an important factor into account, Mercedes Benz S offers a marginal difference of 5% 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, all the models observed together. These are the results of an independent reasearch, while our visitors describe reliability of Mercedes Benz with an average rating of 4.4, and models under the Audi badge with 4.2 out of 5. Independent research findings rank S as average reliability-wise, and A8 is more or less at the same level.We should definitely mention that owners of cars with the same powertrain as Mercedes Benz S rank it on average as 5.0, while the one under the competitor's bonnet gets 3.0 out of 5.

Audi is a bit more agile, reaching 100km/h in 0.2 seconds less than its competitor. In addition to that it accelerates all the way to 250 kilometers per hour, exactly the same as the other car does. When it comes to fuel economy the winner has to be Audi A8, averaging around 9.5 liters of fuel per 100 kilometers (30 mpg), in combined cycle. We can't ignore that 16% 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. From there things take a different direction, with Audi offering somewhat better performance, just enough to call it quicker. To make things even better, it consumps less fuel! I believe that, when we take all into account, we have only one winner here - the Audi. Nevertheless, let's not forget that people have different preferences and needs, so what really counts is your personal feel. I'm only here to help. 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 thousands of similar, yet so different vehicles.