Rubber mixing machine:Oil to rubber

[Piscator]

Well, rubber is about four times more common than oil, so places for the industrial "mass" production of rubber are quite limited (and even then harvesting rubber with a tool would be cheaper). Places with timber (and the industrial capacity to turn it into oil) which are much more common could produce rubber with less than one third of the base rate. This doesn't sound exactly out of proportion, but we might of course still go a bit lower to preserve the advantage of natural rubber sources.

[diurnal_lee]

What about lowering it by introducing an additional resource needed? Some common artificial rubber reactions are initialized by sodium, so--require a pinch of salt, maybe?

[Andu]

I think it would be better with just lowering the output then, than introducing a third needed component.