I know of a couple of diesel engines with severe issues regarding coking up of valves (I work in central warranty for a manufacturer).
I would advise anyone who has bought a GDi Morgan to run it exclusively on Shell fuels, preferably Optimax. Shell are the only oil company I know of who have replaced all fuel storage tanks on the forecourts to catch all water vapour before being dispensed into the car.
Secondly, give it a damn good thrashing once a month (I'm available for hire incidentally).
