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 coupe 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 325hp 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. Moving further on, let's take a closer look at some additional safety-related facts. Both vehicles belong to the sports car segment, which is generally classifying them somewhere in the middle safety-wise, but it doesn't do much to help us decide between the two. Furthermore, taking kerb weight as an important factor into account, 911 offers a marginal difference of 4% 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. That's the official data, 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. That apart, owners of different cars powered by the same engine as 911 rank it on average as 3.0 out of 5, exactly the same as the other one.

BMW is a bit more agile, reaching 100km/h in 0.1 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 250 kilometers per hour, 30km/h less than the other car. When it comes to fuel economy the winner has to be 911, averaging around 11.3 liters of fuel per 100 kilometers (25 mpg), in combined cycle. We can't ignore that 7% difference compared to BMW Z4.

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 Porsche being considerably quicker, thus putting more smile on driver's face. To make things even better, it consumps less fuel! I believe that, when we take all into account, we have only one winner here - the Porsche. 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. 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.