I have a 2007/57 Vectra estate with the 1800 petrol engine. At low revs in 1st/2nd gear I sometimes get a power loss for a few seconds. It then needs some revs to get going. After reading a few articles where you recommend the Superunleaded petrol I now use the problem has gone away, but I still want to know if this is normal for the engine as far as you know. My understanding was that the engine should run on standard Unleaded as it should automatically adjust to the Ron being used