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 6-cylinder, 24-valves 192hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 147hp 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, still it doesn't help us solve our dilemma, does it? Furthermore, when it comes to weight, a factor that most people underestimate, BMW Z4 offers a potentially life-saving difference of 45% more metal.

Reliability is not the best thing to consider on the make level, but it is worth mentioning that Opel does have a slight advantage, when all the models are taken into account. These are the official statistics, while our visitors describe reliability of BMW with an average rating of 4.1, 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. That apart, owners of different cars powered by the same engine as BMW Z4 rank it on average as 2.8, while the one under the competitor's bonnet gets 4.2 out of 5.

Opel is undoubtly more agile, reaching 100km/h in 1.1 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 217 kilometers per hour, 18km/h less than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 8.7 liters of fuel per 100 kilometers (32 mpg), in combined cycle.

Opel 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 beats the other contender by far, making it the best choice without even considering other things. When it comes to performance, both vehicles provide similar experience, so I wouldn't point any of them out. Speedster still consumps less fuel, which needs to be taken into consideration. It's not difficult to say then that if I'd need to make a choice, it would definitely be the BMW. Nevertheless, let's not forget that people have different preferences and needs, so what really counts is your personal feel. I'm only here to help. Also, you could use the oportunity to find out which car, everything taken into account, would be the perfect choice for you in the eyes of the virtual adviser™, among more than 12.000 different ones in our database.