Oil refiners may be taxed more and drivers may see higher taxes at the pump if the House Republican tax plan becomes law, lobbyists and analysts have realized upon sorting through its provisions.

Those groups could be among the “losers” created by the overhaul plan, which Republicans defend as being meant to stimulate overall economic growth and cut down on inequities in the tax code. While the several moving parts of the plan make it difficult to say for sure whether any given group would be harmed, some energy producers have expressed concern about the plan’s border-adjustment feature.