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 (4 x 4 for the Audi and rear in the case of the Mercedes Benz). The first one has a Volkswagen-engineered powertrain under the hood, a 4-cylinder, 16-valves 211hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 204hp engine designed by Mercedes Benz.

The fact that the Audi got tested by the European New Car Assessment Programme (Euro NCAP), while the other contender didn't, offers a slight advantage, as the 4-star rating is better than none. 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. On the other hand, taking kerb weight as an important factor into account, SLK offers a marginal difference of 5% 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, all the models observed together. That's the official data, 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. Unfortunatelly, I don't have enough insight that would allow me to comment in more details on the specific models level. Above it all, drivers of cars with the same engine as Audi TT rank it on average as 3.6, while the one under the competitor's bonnet gets 3.0 out of 5.

Audi is a bit more agile, reaching 100km/h in 0.7 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 240 kilometers per hour, 4km/h less than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 7.2 liters of fuel per 100 kilometers (40 mpg), in combined cycle.

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 TT offers much better overall protection, which launches it ahead of the other contender. When it comes to performance, both vehicles provide similar experience, so I wouldn't point any of them out. SLK still consumps less fuel, which needs to be taken into consideration. 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. 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.