Turbocharger and turbine wheel

A turbine wheel (100) for a turbocharger (10) comprising:

• a hub (110) having a primary outer surface (116), a back wall surface (115), a peripheral edge (119) extending between the primary outer surface (116) and the back wall surface (115), and a central axis (111), wherein the hub (110) has a back wall thickness that is measured parallel to the central axis (111) from the primary outer surface (116) to the back wall surface (115);
• and a plurality of blades (120) extending from the primary outer surface (116) of the hub (110) and integrally formed with the hub (110) via a casting process, wherein each of the blades (120) has a blade thickness that is measured tangential to the central axis (111) between opposed surfaces (123, 124) of the blade (120);
• wherein a diameter of the peripheral edge (119) is 60 mm or more;
• and wherein over a majority of a radially outer region (117), a thickness ratio of the blade thickness to the back wall thickness is between 0.8 and 1.2, the radially outer region (117) extending from the peripheral edge (119) to a 25% meridional distance along the primary outer surface (116), wherein the majority includes a 15% meridional range along the primary outer surface (116).