Well in 2010 I brought the Rapide to Europe (The Woolly) spent 3 weeks in the UK, then over to France, Belgium, Holland, Germany (Rally), Austria (Rally), Italy, (Rally) and back through Monte Carlo and up the Rue de Napoleon and back to the UK, 9 1/2 weeks and several thousand miles, used one litre of oil for the whole trip, NO seals on the Exh guides, so more than just a good theory. That was two up with full luggage and as some may tell you, I am not necessarily easy with the throttle hand......
That by the way, was after 8 weeks across Australia in 2007. Only used some oil on that trip after the gasket on the No 1 Rocker feed bolt banjo split, everything else stayed dry. Still running that engine untouched for about 70 K miles and still uses very little oil.....