The longest manned lunar rover trip was more like 15km (7.5km out and back on Apollo 17) and the limiting factor there was that the astronauts had to be ready t

The longest manned lunar rover trip was more like 15km (7.5km out and back on Apollo 17) and the limiting factor there was that the astronauts had to be ready to walk back if it broke down. If the mission called for the astronauts to walk 23km in a single trip on Mars, designing the technology for that would not be a huge leap. I agree the extra weight required for life support and a return journey would be far greater than what the unmanned rovers need.