I feel like this is a large portion of the missing puzzle pieces. The difference between real world and advertised ICE stats are somewhat padded, but not significantly. You’d expect the hybrids to have a similar degree of discrepancy, but it’s wildly out of range of expectations. It may simply be that the manufacturers are giving idealized stats, since while testing they would have access to their personal charger in a laboratory environment. But in the real world, owners cannot guarantee working/accessable chargers or even that they can charge at home, which would dramatically impact the results of this study.
Or at least, I’d assume that’s the case in the US. I don’t know what EU’s charging infrastructure is like, where the study was preformed.