just read this
What fuel is best to use?
The GT Turbo was designed for 97-99 RON leaded four star petrol in the UK. However, as leaded fuel wasn't present in all the places it's sold, it's probably safe to use unleaded without any significant damage to the valve seats occurring. The main problem is the octane (RON) rating. You should use 98RON Super Unleaded, 99RON Shell Optimax or 98RON leaded four star. If you're stuck, a fiver's worth of 95RON Premium Unleaded will get you to somewhere that sells Super or Optimax, but due to it's lower octane running Premium Unleaded will cause engine damage if used on boost for any length of time. Stay well away from Lead Replacement Petrol (LRP) - although it's octane rating is good, it contains lead substitutes that attack the turbo internals due to the high temperatures there.
im confused now, do i use 4 star or carry on using normal 97?
i thought unleaded in a car designed for 4 star leaded dint last long?
thng is i fill up at 4 diffrent stations, depended on were i am when im low and depended on what direction im going from my house. and one is so expencive for super i dont bother
so should i make the effort to go get super or will i make no diffrence?
thing is with the car eating 14/17mpg i dont realy earn enoth to keep feeding it super