Anyone had issues running Super Unleaded (97 RON) in their stock S1? I'm noticing a slight misfire under heavy load, accelerating hard uphill in 5th or 6th. I fear the plugs and / or coil pack(s) are done for, possibly caused by the type of fuel used. I use the same Super Unleaded in the wife's Skoda Fabia 1.2 TSi and that has developed a misfire in every gear but no engine management light. I live on an island and there are unconfirmed reports that our one pump of 'Super Unleaded' is actually standard 95 RON unleaded with an Octane Booster added by the retailer. Also, with little demand for the fuel, there will be little turnover in the storage tank. Any thoughts?