

Engines have gotten somewhat more efficient in the past 25 years, but not that much more efficient. For example, a 2026 base-model Tacoma is a whopping 3 MPG more efficient than a 2001 base-model Tacoma (according to the EPA, anyway; according to vehicle owners they’re the same).
https://fueleconomy.gov/feg/Find.do?action=sbs&id=16989&id=50081
Internal-combustion engines are a pretty mature technology, especially once you’re talking new enough to have fuel injection. Other than stuff like Atkinson-cycle engines (which only apply to hybrids), the small refinements in efficiency since the '90s aren’t anywhere near enough to overcome the vast size/weight/capacity difference from a reasonably-small truck to a gigantic one.











Eh, a Tacoma is generally going to be better than a 3500 for climbing over obstacles because it’s more nimble and has better approach/breakover/departure angles. A bigger vehicle (aside from the tires) isn’t necessarily better for that sort of thing.