What fuel should I use?

It is officially recommended to use a minimum of Super Unleaded (98 RON) in all Evolution models in Europe. Where the Lancer Evolution models are built initially for Japan, the car is forseen to run on Octane 100 RON or higher. The engine management in the Evolutions can adapt to lower octane fuels but performance will be reduced to prevent detonation. The higher the octane fuel you use the less chance detonation will occur allowing better performance. Be sure to get your fuel at major brand fuel pumps like Fina-Total, Shell, Esso or BP. Do not try to run on cheaper fuel or Octane levels below 98 RON.

As for 95 RON Premium Unleaded the official advice is do not use it unless in an emergency. If you have to fill up with 95 RON Unleaded for any reason then drive carefully until you get a chance to fill up with a Super grade unleaded again. It is also officially recommended that Octane Boosters are not used, even in an emergency. If you have to or want to run on a lower RON rated fuel then it may be wise to reprogram the engine ECU to suit low Octane rated fuel or fit an aftermarket ECU system or ignition controller (basically retard the ignition map slightly to prevent detonation). If you experience detonation in winter times when engine power is remarkable higher, please consider to reprogram the engine ECU.