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 Mercedes Benz-engineered powertrain under the hood, a 8-cylinder, 32-valves 455hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 333hp engine designed by Volkswagen.

The fact that the Audi got tested by the European New Car Assessment Programme (Euro NCAP), while the other contender didn't, puts it sky-high safety-wise, in my eyes at least. Still, apart from the official crash test results there are other things we need to be aware of. Both vehicles belong to the suv segment, which is generally a very good thing safety-wise, but that fact doesn't break the tie between the two cars. Furthermore, if we'd like to consider vehicle mass in this context too, which we definitely should, GLS offers a considerable difference of 22% more metal.

Manufacturers have been building their reliability reputation for decades now and, generally speaking, it appears that both brands display similar results in faults and breakdowns, at least on all of the models level. That's the official data, while our visitors describe reliability of Mercedes Benz with an average rating of 4.4, and models under the Audi 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. We should definitely mention that owners of cars with the same powertrain as GLS rank it on average as 3.0, while the one under the competitor's bonnet gets 4.3 out of 5.

Mercedes Benz is a bit more agile, reaching 100km/h in 0.8 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 250 kilometers per hour, exactly the same as the other car does. When it comes to fuel economy an obvious choice would be Audi Q7, averaging around 7.7 liters of fuel per 100 kilometers (37 mpg), in combined cycle. That's 47% difference compared to GLS!

Audi 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, Audi Q7 beats the other contender by far, making it the best choice without even considering other things. From there things take a different direction, with Mercedes Benz offering somewhat better performance, just enough to call it quicker. It does come at a cost though, and that's the fuel consumption... All together, there's not much more to say, in this case I wouldn't even consider anything but Audi. 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. 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™, among thousands of similar, yet so different vehicles.