Cheebye, oh sorry, i shoulda read your sig, it said DC5-R.

Why would you want to run Genuine Honda FEO until 40-50,000km and then change to full synthetic? Is the Honda FEO a full synthetic? cos i don't think it is. and if it isn't a full synthetic: DON'T DO IT!

there is a problem with running mineral oil for alot of km's and then switching over to a full synthetic.

what happens is your O rings get worn more due to running for a lot of km's on mineral oil, when u switch over to a full synthetic, it provides better lubrication, and as a result it can get through the the tiny gap between the O rings and the cylinder walls. Means you burn more oil.
but of course, if you just continued using the same oil for the rest of the cars life, you wouldnt have this excess oil consumption problem

it is recommended you change over to a full synthetic early on in the cars life and stick with it, especially with a high revving DOHC Vtec.

keep in mind, its also bad to chop and change brands and viscosity of oils all the time.

Chris