Always use Millers Ecomax petrol Treatment as was recommended some time ago as an Excellent additive to keep Engine clean and running well. Used in conjunction with Shell V power super petrol or Esso Synergy Supreme+ 99*. Have also used Tesco momentum. Any super fuel better for your engine if you intend to keep car running smoothly. ECOMAX Addative is used as an extra precaution with noticeable smooth running of engine. Touch wood my 12 year old Vauxhall Zafira B 1.6 capital Edition at 63000 will continue to run efficiently with limited wear and tear to Engine Components.