Last night on the way to the bodyshop I put in £5 of normal 95 unleaded from a local station. I have been running it on Optimax or BP Ultimate for the last few months.
The further I got to the bodyshop the more the car would start missing and appeared to run on 3 cylinders.
It gradually got worse and by the time I got to the bodyshop, any time you put more than 1/3 throttle it would miss or jump onto 3.
I didnt have time to look at it last night.
This morning the guy said that when he took it up the road it was fine when cold but when it warmed up it started messing about again.
I checked the plugs a week ago and they looked ok.
Could it be the fact that it was on 97/98 petrol and has now been mixed with 95?
Any ideas what it is?