Powering a furnace cart up an ascending railway from y=66~319 revealed no slowdown for the cart, and even after it fell down to the ground, it retains the smoke particles, indicating that it still has power. Pushing it onto another railway also boosts the cart right back up.
MC-260006
Furnace Minecarts have infinite boost from 1 coal
Resolved
Awaiting Response
1
(Unassigned)
Confirmed
Platform
Very Important
Minecart
23w06a, 1.19.4 Pre-release 2
Retrieved
Can you clarify what is wrong with current behavior? It is powered for 3 minutes by 1 coal and then stops.