I wouldn't trust any oil to last 15 years. No matter what they claim it can do, it's unreal.
1969 Chrysler Newport Custom - mine - 383 4bbl, 727 Torqueflite with shift kit, dual glasspacks
upcoming mods - Flowmasters, Edelbrock intake, Hooker headers
1998 Mercury Grand Marquis - my mom's
upcoming mods - possibly a K&N FIPK
2005 Ford Focus - my dad's