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 4-cylinder, 16-valves 163hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 200hp engine designed by Opel.

The fact that the Mercedes Benz 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. 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 potentially life-saving difference of 36% more metal.

I don't like generalizing things when it comes to reliability, although it does seem that Opel 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 4.3, and models under the Opel badge with 4.2 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 4.3 out of 5.

Opel is way more agile, reaching 100km/h in 3.3 seconds less than its competitor. In addition to that it accelerates all the way to 243 kilometers per hour, 20km/h more than the other car. When it comes to fuel economy the winner has to be Speedster, averaging around 8.5 liters of fuel per 100 kilometers (33 mpg), in combined cycle. We can't ignore that 13% difference compared to SLK.

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, SLK beats the other contender by far, making it the best choice without even considering other things. From there things take a different direction, with Opel outracing its opponent in any situation possible, making it better choice for boy racers. To make things even better, it consumps less fuel! No mistake, whatever you decide here, but I'd still go for the Opel. 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.