I see he recomends an oil change and filter change every 5K
The oil filter and oil cartridge are the same thing. They use to change filters as they were all in one, now you just change the cartridge insides of the plastic filter (the paper type eliment on the inside) Its more messy. Its to save the enviroment so they say,
As an engineer i find this quite funny as cars from the 50s and 60s had cartridges you changed and going over to encased plastic filters was looked on as a progress. Now we have gone back the other way. Funny this progress lark.