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 2-door cabriolet body style within the same 'Sports car' segment, the only major difference here really is their wheel drive configuration (rear for the Mercedes Benz and front in the case of the Audi). The first one has a Mercedes Benz-engineered powertrain under the hood, a 6-cylinder, 24-valves 316hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 265hp 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. That aside, let's consider some other aspects which affect safety. Both vehicles belong to the sports car segment, which is generally classifying them somewhere in the middle safety-wise, but that fact doesn't break the tie between the two cars. Furthermore, if we'd like to consider vehicle mass in this context too, which we definitely should, Mercedes Benz SL offers a marginal difference of 1% more metal.

I don't like generalizing things when it comes to reliability, although it does seem that both brands display similar results in faults and breakdowns, when all the models are taken into account. That's the official data, 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 SL 50% below average, and A5 Coupe is more or less at the same level.That apart, owners of different cars powered by the same engine as Mercedes Benz SL rank it on average as 3.0 out of 5, exactly the same as the other one.

Mercedes Benz is a bit more agile, reaching 100km/h in 0.7 seconds less than its competitor. In addition to that it accelerates all the way to 250 kilometers per hour, 4km/h more than the other car. When it comes to fuel economy the winner has to be A5 Coupe, averaging around 8.6 liters of fuel per 100 kilometers (33 mpg), in combined cycle. We can't ignore that 13% difference compared to Mercedes Benz SL.

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 SL offers slightly better overall protection and takes the lead. It all continues in the same direction, with Mercedes Benz 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 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. 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™, among thousands of similar, yet so different vehicles.