TL;DR
dislike how you need to fuel your furnaces with solid fuel? let's reinvent fossil fuels!What ?
This is changed mainly targeted at furnaces, but this change would affect vehicles aswell.Liquid fuel furnaces (crude oil). very fast and based on fuel eko friendlier (furnace with base speed of 3, but at comparably little pollution). The furnaces are pipes for other next to furnaces (similar to uranium mining).
Solid fuel will be removed and rocket fuel is made directly from flammable chemicals (light oil and heavy oil, light oil, light oil and petroleum gas). vehicles can use barrels of flammables as fuel and would implement gas tank mechanic (even for coal, wood), this would work similarly for trains (train can be refueled using pumps).
Why ?
at current moment the transition from fueled furnaces is directly to electric. which uses double the energy consumption. which in return requires solid power grid expansion. the liquid fuel furnaces could be intermedaite move before upgrading to electric and then to modular electric smelting.the second being rocket fuel is made out of solid fuel and light oil and i think that could be removed in favor of liquid fuels (this would ulimately remove even nuclear fuel. and vehicle speed benefits based of fuel type but with different liquids).