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 coupe 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 343hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 325hp engine designed by Porsche.

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, but that fact doesn't break the tie between the two cars. On the other hand, when it comes to weight, a factor that most people underestimate, 911 offers a marginal difference of 5% more metal.

Reliability is not the best thing to consider on the make level, but it is worth mentioning 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 BMW with an average rating of 4.2, and models under the Porsche badge with 3.7 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 BMW Z4 rank it on average as 3.0 out of 5, exactly the same as the other one.

Both of the cars accelerate exactly the same, so we couldn't put one above the other. Car No. 2 is faster though, reaching top speed of 285 kilometers per hour, 35km/h more than the other car. When it comes to fuel economy the winner has to be 911, averaging around 11 liters of fuel per 100 kilometers (26 mpg), in combined cycle. We can't ignore that 10% 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. When it comes to performance, both vehicles provide similar experience, so I wouldn't point any of them out. 911 , on the other hand, consumps significantly less fuel, and that's a big plus. It's really tough to make a final decision here, but if I'd need to, I'd say Porsche. 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. 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.