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 BMW-engineered powertrain under the hood, a 4-cylinder, 16-valves 150hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 264hp engine designed by Opel.

The fact that the BMW 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. On the other hand, taking kerb weight as an important factor into account, Opel GT offers a marginal difference of 9% more metal.

Manufacturers have been building their reliability reputation for decades now and, generally speaking, it appears that Opel does have a slight advantage, all the models observed together. These are the official statistics, while our visitors describe reliability of BMW, as well as Opel, with the same average rating of 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. That apart, owners of different cars powered by the same engine as BMW Z4 rank it on average as 4.3, while the one under the competitor's bonnet gets 3.0 out of 5.

Opel is undoubtly more agile, reaching 100km/h in 2.5 seconds less than its competitor. In addition to that it accelerates all the way to 229 kilometers per hour, 9km/h more than the other car. When it comes to fuel economy the winner has to be BMW Z4, averaging around 7.5 liters of fuel per 100 kilometers (38 mpg), in combined cycle. We can't ignore that 23% difference compared to Opel GT.

BMW 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, BMW Z4 offers much better overall protection, which launches it ahead of the other contender. From there things take a different direction, with Opel being considerably quicker, thus putting more smile on driver's face. 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 BMW. 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.