Re: Tuning mk6 for 98 premium
The ecus are tuned to run 95 ron fuel already. So tuning it to run 98 ron petrol without any other mods will have minimal effect.
But once you get some mods you can get the ecu reflashed and get some nice gains.
2004 Ford Fiesta Zetec. Colorado Red . Mods - BMC air filter, Xenon Blue headlights, Slightly modded intake. 58.3 FWKW.