@MrTesco could you please post up a photo of your under-bonnet load/axle plate or the figures.
@T6AL has a gross weight listed on his V5 of 3080kg which would appear to conform to T30 equivalent van or Kombi. However, only a dealer can tell you from looking up the build sheet what elements have been used for suspension etc. as the Shuttle is a separate line and not a load carrying vehicle. Caravelle wheels from the brochure are 16" for the 150ps SWB and 17" for the 150ps LWB and 204ps LWB.
It seems like a careful check is required of spec and build sheets to see just what wheels should be fitted as standard to the Shuttle as only 16" are listed in the brochure for the 84ps SWB with 17" for all others, alloys are an option in the current March 2017 brochure.
Sorry if this is garbled but it's way late.