As reported on Left Lane News, the 2014 Sprinter will have the 2.1 diesel engine that is also in the GLK. It will be detuned on hp and torque to "increase reliability" and offer a 37,000 mile oil change frequency!

Does that mean that the GLK engine is inherently "less reliable"?

I would never run any oil for 37k miles, regardless of the recommendations from MB. I can see how that may seem attractive to the fleet owners in the beginning, but I'm not so sure about the long term.