Those of us that own or have owned pre-Boxster (i.e. pre-1996) Porsches have faced this problem for ages. Basically in this country if you use 98-99RON fuel there is no problem and so far it appears all fuel suppliers will continue to have no more than 5% in their high RON fuels. However, on the continent beware! Most or all fuel pumps have to display a sticker showing E5 or E10 as well as the RON number, so whenever I had my 968 in Europe I always headed for the 98-99RON pump feeling smug - until I pulled up in front of a pump in Northern Spain and found that although it was 99RON it had an E10 on the pump! Swiftly moved on to a different petrol station! Shortly thereafter, in a Repsol station, I was told that Repsol do not use ethanol in their petrol - but that was 6 years ago and may have changed. Basically, in an older car with the unsuitable fuel lines, the E10 can strip the inner lining so bits progress through the fuel system into the pump and injectors, with disastrous consequences. I've read that you can change everything between the tank and the injectors to prevent this, but I found it easier and cheaper to stick to 99RON in my 968 - and the car ran better than on 95RON, and with the limited mileage I did each year the incremental cost was almost un-noticable.