The Volkswagens and Saabs in question were mainly mid '80s to early '90s models. As mentioned, the Hyundai was an '06. I have a full listing of oil specs at the shop, for pretty much any production car and truck back to the '70s.
15w40 might be exsessive in a gas engine (non turbo), but it is the common grade specified in virtally all light truck deisels.
