Found http://www3.shell.no/op/smidler/prodhbok/helixult.htm with references to Shell Helix Ultra Specs (HTHS). reproduced here partially.
Viskositetsgrad, SAE 0W-40 5W-40 10W-60
Viskositet, cSt/40°C 75,2 74,4 151
Viskositet, cSt/100°C 13,6 13,1 22,8
Viskositetsindeks 187 187 0,85...