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 (4 x 4 for the Audi and rear in the case of the Mercedes Benz). The first one has a Audi-engineered powertrain under the hood, a 6-cylinder, 24-valves 233hp unit, while the other one gets its power and torque from a 6-cylinder, 24-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. 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, but that fact doesn't break the tie between the two cars. Furthermore, taking kerb weight as an important factor into account, Audi A8 offers a marginal difference of 1% 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. 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 4.3 out of 5. The same official information place A8 as average reliability-wise, and S is more or less at the same level.Above it all, drivers of cars with the same engine as Audi A8 rank it on average as 4.6, while the one under the competitor's bonnet gets 5.0 out of 5.

Audi is a bit more agile, reaching 100km/h in 0.4 seconds less than its competitor. In addition to that it accelerates all the way to 243 kilometers per hour, 8km/h more than the other car. When it comes to fuel economy the winner has to be Mercedes Benz S, averaging around 7.7 liters of fuel per 100 kilometers (37 mpg), in combined cycle. We can't ignore that 10% difference compared to Audi A8.

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, Audi A8 offers slightly better overall protection and takes the lead. It all continues in the same direction, with Audi being considerably quicker, thus putting more smile on driver's face. 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. 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.