I have a microtech wide band. Does anyone know what the 3-way switch is for?

P / G / A

I think i remember being told the following

P = Petruleom (pump gas)
G = Gas (race fuel like VP)
A = Alcohol

I know it give completely different readings when switched from one to another.

 

p is for petrol, race gas etc
G is for LPG gas
A is for methenol