Recommended rim sizes for Sorrento:
7Jx17 ET41
7.5Jx18 ET41
7.5Jx19 ET51
8.5Jx20 ET54
They all have less offset (about 10 mm less, 20% btw) which means that wheels will not stick out of the arches but may cling brake calipers. I'd avoid such a change.