I've been running 95 ron for quite a while now, due mainly to the availability of it (hard to get hold of 99 ron). Question is if I get a remap done now with this fuel, it would obviously limit the max power/torque on the rolling roads. But what if I later use 99 ron, because the custom map was done with 95 ron fuel will it limit the potential or something like that (can't exploit 99 ron)? If it does, I just need to wait a couple of months before I empty the current tank of fuel and go through a full tank of 99 ron first. I remember fifth gear saying that it takes about 2 tanks of 99 ron for the ECU to adapt to it/to take advantage of.
If it's mapped for 95 thats really what you need to run it on... Is there not a Tesco or something near to you that does 99RON? Alternatively you can get octane booster quite easily but would probably work out quite expensive if relied on each tank. I wouldn't pay too much attention to Fifth Gear tbh, the car will adapt fairly soon after filling up especially with a few stop/start spirited blasts in the same outing.
