Cut out on way to work

[Coopstar]

Hello all.
Any ideas gratefully accepted on this one, hopefully the fuel is at fault.
Basically I have always used 98 octane for the few thousand miles I have done.
Last weekend I put some 95 in, ran fine for a few niles then misfired/pinked for a mile, pulled into services when the engine started running fine again.
Did around 100miles afterwards no trouble.
Did 60miles yesterday no probs, put somemore fuel in (95 again).
Tonight going to work in the glorious sun, after about 6 miles had total power loss and had to coast to a halt.
Tried restarting, died instantly, and again.
Third time lucky, revved it a bit, lovely job.
Drove reast of way to work no probs, quick/slow/full throttle to no throttle, sound.
Question is, will the fuel be causing this or something more infuriating (as in a bugger to find).
Shall I just forget it and start using the 98 again.
Sorry for the length of the post, got carried away.
Any advice appreciated.
ps, enjoy the sun this week, should be some nice driving to be had!!

>> Edited by Coopstar on Monday 15th August 19:51