I'm looking for a recomendation on what oil for my 2000 Honda XR250R - I don't know what the previous owner was running in it. Now my choice is from 3 Castrol products, the first is the mineral Active 4T, second is the semi-synthetic GPS and the third is the full synthetic R4 Superbike. Price between the products is irrelevent for this (but if anyone cares it seems the semi-synthetic is the most expensive, then the full-synthetic, then mineral is the cheapest - strange, I thought full would be the most expensive). All three are listed in the Castrol book for this bike. So which to go with? I've had 1 person express concern about using the full synthetic R4 Superbike in it as they reckon it will probably burn a bit of it or something due to the type of riding in the bush.