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 Porsche and rear in the case of the BMW). The first one has a Porsche-engineered powertrain under the hood, a 6-cylinder, 24-valves 480hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 343hp engine designed by BMW.

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. 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, still it doesn't help us solve our dilemma, does it? Furthermore, when it comes to weight, a factor that most people underestimate, 911 offers a considerable difference of 17% more metal.

I don't like generalizing things when it comes to reliability, although it does seem that BMW does have a slight advantage, when all the models are taken into account. These are the results of an independent reasearch, while our visitors describe reliability of Porsche with an average rating of 3.9, and models under the BMW badge with 4.1 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 911 rank it on average as 3.0 out of 5, exactly the same as the other one.

Porsche is undoubtly more agile, reaching 100km/h in 1 seconds less than its competitor. In addition to that it accelerates all the way to 310 kilometers per hour, 60km/h more than the other car. When it comes to fuel economy the winner has to be BMW Z4, averaging around 12.1 liters of fuel per 100 kilometers (23 mpg), in combined cycle. We can't ignore that 7% difference compared to 911.

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 significantly better overall protection, taking the lead here. From there things take a different direction, with Porsche outracing its opponent in any situation possible, making it better choice for boy racers. It does come at a cost though, and that's the fuel consumption... It's really tough to make a final decision here, but if I'd need to, I'd say BMW. Anyway, that's the most objective conclusion I could've came up with and it's based solely on the information found on this website. Aspects such as design, practicality, brand value and driving experience are there for you to measure them out. 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™, among more than 12.000 different ones in our database.