That was a very different car - a heavy, 7 passenger SUV (X5) vs the comparatively modest VW sedans. What's going on there? Was it held to a different standard?

That was a very different car - a heavy, 7 passenger SUV (X5) vs the comparatively modest VW sedans. What's going on there? Was it held to a different standard? Does its bigger engine not have to work as hard? Edit: I read the relevant bit of the paper. 6 cylinder engine vs. the 4 pots in the VWs, and probably more importantly it had a urea NOx reduction system so perhaps that made the difference.