Earlier in the year I blew a head gasket and the head was a bit rooted so I got some work done on it. Due to the work I had to run 95 octane at the least but someone borrowed my car and filled it up with shell 91. I never fill up at Shell usually.
The engine doesn't pink so I'm driving it with the 91 but it's incredibly gutless and the spark plugs fouled in less than a day, I only gave the car a tune up a week ago.
Do you think its gutless due to the fuel, fuel quality or something else?
Its got me slightly worried but I can't put new gas in yet because its a full tank and theres no drain on the bottom of the tank to get the gas out.