Col666. I had a look on ecutek and the 99v5 sti is listed there .You would need to send Andy Forrest an email and ask him what it would be like on 95ron fuel.If you got remaped on optimax and the car needed fill up and there was no shell garages about .Have a case off millers octane booster in the boot to use with bp ulitmate or esso supreme thats what i think best to ask Andy first about fueling wise.Andy goes up to Awd and remaps there customers cars .