* Gasoline: The gasoline engine options were a 6.0L Vortec V8 or a 6.2L Vortec V8. These engines require regular unleaded gasoline.
* Diesel: The diesel engine option was a 6.6L Duramax V8. This engine requires diesel fuel.
To know for sure which type of fuel your specific 2007 Silverado 2500HD uses, you should check the owner's manual or look at the fuel filler cap, which will specify the fuel type.
