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 sports car segment and utilize the same 2-door cabriolet body style and the rear 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 6-cylinder, 24-valves 306hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 315hp engine designed by Porsche.

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. Still, apart from the official crash test results there are other things we need to be aware of. 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, taking kerb weight as an important factor into account, SLK offers a marginal difference of 7% more metal.

Reliability is not the best thing to consider on the make level, but it is worth mentioning that Mercedes Benz does have a slight advantage, 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 4.4, and models under the Porsche badge with 3.7 out of 5. Unfortunatelly, I don't have enough insight that would allow me to comment in more details on the specific models level. We should definitely mention that owners of cars with the same powertrain as SLK rank it on average as 5.0, while the one under the competitor's bonnet gets 3.0 out of 5.

Porsche is a bit more agile, reaching 100km/h in 0.5 seconds less than its competitor. In addition to that it accelerates all the way to 279 kilometers per hour, 29km/h more than the other car. When it comes to fuel economy the winner has to be SLK, averaging around 7.1 liters of fuel per 100 kilometers (40 mpg), in combined cycle. We can't ignore that 27% difference compared to Boxster.

Mercedes Benz is apparently more reliable, not too much, but just enough. 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, SLK offers slightly better overall protection and takes the lead. From there things take a different direction, with Porsche offering somewhat better performance, just enough to call it quicker. It does come at a cost though, and that's the fuel consumption... All together, there's not much more to say, in this case I wouldn't even consider anything but 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. 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™, out of 12.000+ vehicles we currently have in our database.