The difference with #2
Optimax is Shell's super unleaded, has a higher Ron, pretty much the same as most super unleaded's.
It can be a long winded post, to cut it short, all Jap market cars are desinged to run on 100 RON (the jap standard)
But will run on normal unleaded, but with reduced power.
If you have a normal GS300 designed for the Euro market, normal unleaded will be fine, super unleaded will give you sightly better performance.