The 2007 GMC Yukon runs on regular unleaded.
The 2007 GMC Yukon-XL runs on regular unleaded.
5w30
5w20
5w20
See *What Kind of Oil to Use* on page 314 of your "Owner's Manual".....
20w50
5w-30
Either 5W20 or 5W30.
Use socket
The 2008 GMC Yukon runs on regular unleaded.
The 2003 GMC Yukon runs on regular unleaded.