TL;DR
The vehicle fuel tooltip and Factoriopedia entry for vehicles only show burnable fuel that is already unlocked, but it should show all possible fuels.What?
Before researching a fuel, it does not show up in the Factoriopedia entry or vehicle fuel tooltip for vehicles. For example, at the beginning of the game before oil processing, a train looks like this:- Factoriopedia_Before_Research.png (209.33 KiB) Viewed 158 times
- Vehicle_Fuel_Tooltip_Before_Research.png (87.15 KiB) Viewed 158 times
- Factoriopedia_After_Rocket_Fuel_Research.png (219.43 KiB) Viewed 158 times
- Vehicle_Fuel_Tooltip_After_Rocket_Fuel_Research.png (95.96 KiB) Viewed 158 times
There are no indications that this information is dynamic, and I'm not aware of anywhere else in the game where information is restricted like this. For example, the Factoriopedia entry for nuclear fuel lists a Tank for "Burned in" regardless of whether Tank has been researched. Factorio's design philosophy does not really hide information (you can view the entire tech tree and Factoriopedia from the start) and the fact that rocket fuel can be burned in a train can be deduced from the rocket fuel Factoriopedia page, but it is deliberately omitted from the train Factoriopedia page and the tooltip.
My core suggestion is: the fuels listed for every vehicle should not be restricted to only fuels you have currently unlocked.
I think it's conceivable to indicate that certain fuels haven't yet been unlocked, perhaps by a red background similar to the one behind an un-fulfillable logistics request. Personally, I don't think this is necessary - the audience is well aware that some items are not available yet, and in Factoriopedia they can even click the item and see that it requires research that is not completed.
