>>28569498
They always were about what kind of comparable power, NA power they represent.
For example the old E23 745 with a 3.2 litre turbo 6 had comparable power to a 4.5 litre engine.
E30 316 with the carbed M10B18 was a 1.8 litre 4 banger, but they deemed that the engine puts out power comparable to a 1.6.