Two significantly similar cars, no doubt about that. Still, each one has something different to offer. Having both cars powered by diesel 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 (rear for the Mercedes Benz and 4 x 4 in the case of the Audi). The first one has a Mercedes Benz-engineered powertrain under the hood, a 6-cylinder, 24-valves 197hp unit, while the other one gets its power and torque from a 8-cylinder, 32-valves 225hp engine designed by Audi.

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. That aside, let's consider some other aspects which affect safety. 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? On the other hand, when it comes to weight, a factor that most people underestimate, Audi A8 offers a marginal difference of 2% 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 official statistics, while our visitors describe reliability of Mercedes Benz with an average rating of 4.3, and models under the Audi badge with 4.2 out of 5. The same official information place S as average reliability-wise, and A8 is more or less at the same level.Above it all, drivers of cars with the same engine as Mercedes Benz S rank it on average as 4.5, while the one under the competitor's bonnet gets 3.8 out of 5.

Audi is a bit more agile, reaching 100km/h in 0.3 seconds less than its competitor. In addition to that it accelerates all the way to 242 kilometers per hour, 14km/h more than the other car. When it comes to fuel economy the winner has to be Mercedes Benz S, averaging around 8.9 liters of fuel per 100 kilometers (32 mpg), in combined cycle. We can't ignore that 9% difference compared to Audi A8.

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, Audi A8 offers slightly better overall protection and takes the lead. It all continues in the same direction, with Audi 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... At the end, as much as I'd like to give you a winner here, it's simply a pure tie if you ask me. 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. 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™, out of 12.000+ vehicles we currently have in our database.