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 suv segment and utilize the same 5-door suv body style and the 4 x 4 wheel drive system, it all comes up to the specific petrol engine choice they offer. The first one has a Porsche-engineered powertrain under the hood, a 8-cylinder, 32-valves 520hp unit, while the other one gets its power and torque from a 8-cylinder, 32-valves 575hp engine designed by BMW.

Unfortunatelly, neither of the two vehicles was submitted to the European New Car Assessment Programme (Euro NCAP) testing. This makes it virtually impossible for me to pick one over the other and I'm generally against buying such cars as the safety should really always come first. That aside, let's consider some other aspects which affect safety. Both vehicles belong to the suv segment, which is generally a very good thing safety-wise, but it doesn't do much to help us decide between the two. On the other hand, taking kerb weight as an important factor into account, BMW X6 offers a marginal difference of 3% more metal.

I don't like generalizing things when it comes to reliability, although it does seem that BMW does have a slight advantage, at least on all of the models level. 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. The same official information place Cayenne as average reliability-wise, and X6 is more or less at the same level.That apart, owners of different cars powered by the same engine as Cayenne rank it on average as 3.0, while the one under the competitor's bonnet gets 4.0 out of 5.

BMW is a bit more agile, reaching 100km/h in 0.3 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 250 kilometers per hour, 29km/h less than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 11.3 liters of fuel per 100 kilometers (25 mpg), in combined cycle.

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 X6 offers slightly better overall protection and takes the lead. From there things take a different direction, with Porsche offering somewhat better performance, just enough to call it quicker. It does come at a cost though, and that's the fuel consumption... I believe that, when we take all into account, we have only one winner here - the 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. 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 thousands of similar, yet so different vehicles.