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 rear wheel drive system, it all comes up to the specific diesel engine choice they offer. The first one has a Mercedes Benz-engineered powertrain under the hood, a 4-cylinder, 16-valves 143hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 143hp engine designed by BMW.

A starting point here would be to take a look at the results from European New Car Assessment Programme (Euro NCAP) tests which were performed on both of the cars, with the same number of safety stars gained in the process. 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 it doesn't do much to help us decide between the two. Furthermore, taking kerb weight as an important factor into account, GLK offers a marginal difference of 4% more metal.

I don't like generalizing things when it comes to reliability, although it does seem that both brands display similar results in faults and breakdowns, when all the models are taken into account. These are the official statistics, while our visitors describe reliability of Mercedes Benz with an average rating of 4.4, and models under the BMW badge with 4.2 out of 5. The same official information place GLK as average reliability-wise, and X3 is more or less at the same level.That apart, owners of different cars powered by the same engine as GLK rank it on average as 3.0, while the one under the competitor's bonnet gets 4.1 out of 5.

BMW is a bit more agile, reaching 100km/h in 0.4 seconds less than its competitor. In addition to that it accelerates all the way to 195 kilometers per hour, exactly the same as the other car does. When it comes to fuel economy things look pretty much the same for both cars, averaging around 5.3 liters of fuel per 100 kilometers (53 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, GLK offers slightly better overall protection and takes the lead. From there things take a different direction, with BMW offering somewhat better performance, just enough to call it quicker. 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 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. 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.