That would a lot of gas but what a journey, eh! If only I had the time and permit from SWMBO
Naturally, it would take some care in route choice. S. Africa through Kenya should be pretty safe, as would a western route sticking to the coast once you get north of Angola. The sticking points on the east side would be getting through Sudan to Egypt---and trying to go up the center across the Sahara is simply not to be considered.