It's been a long for me being off the BBS, the joys of travelling ! I'm now in NZ and my car arives today ! The bad news is I can't find any fuel over 96 Octane.

My Jap WRX is mapped to 97 Octane, and i've been using Shell Optimax in the UK, rated at 98 I beleive. I was told there is 98 in NZ, but haven't seen any yet.

Some questions.
1) If car is mapped for 97, is it true that 95 (NUL in UK) will do the engine damage. And if so, what about 96 (SUL in NZ).

2) Again if car is mapped for 97, was using 98 in the UK doing the car harm as well ?

3) In techno speak, ie please be technical, what does remapping do in terms of ECU and the way fuel/air burns in the cylinder.

Any help would be appreciated, as would links to other threads and/or websites.

Airhead.

There are two suppliers of 98 in NZ - BP (Optima) and Caltex (Synergy 8000).

They are stocked throughout Auckland and down SH1, but not so much in the rest of the country.

You can go to www.bp.co.nz and search for service stations that offer it.

Alternatively, the Challenge 96 octane rated petrol is apparently almost 98 anyway (a friend who rallies had some tested), so that could be another option if you get stuck off the beaten track.

Thanks, yes now have found some 98 octane. Think Mobil does the synergy 8000, not Caltex !

Yep, you are right, Mobil I mean't.

BTW - apparently the Challenge petrol is now the same stuff that Mobil offers (i.e. only 96). They have been assimilated.