ORIGINAL: GallopingGhostler
AFAIK, Europe has been using FAI or no nitro fuel for ages. Nitro content is reported to make needle valve settings less critical, smaller engines use it for higher RPM. If no nitro fuel works fine for you, there's no reason to change.
They ran a lot of diesels too- as I still do. The nitro is a help in the dinky-toy stuff as it will provide more power and an easier to set needle. I have run some of my OK Cub .049's on a straight FAImix tho,and they did just fine.
John