Having read all that stuff about hydrocracked mineral oil, being called synthetic, it's got me wondering, and Tbh, if these so called fully synthetic oils are in fact just that ????
I must admitt i was once told by a very well known engine builder & turbo cossie specialist that they only ever run their 500bhp cossies on semi Sythn, as it's good enough, no need to go to the expense of fully sythen.
Since then I've only ever run my cars and bikes on semi sythetic oil, also its considerably cheaper than a lot of "so called" fully sythetic oil.
It would be interesting to find out what oil Seat recommend if it's a proper fully sythentetic or semi sythen or mineral oil.