Pcm

Why do u need premium fuel with a PCM. Is it just because of the higher octane? and if it is would octane booster work or do u need premium

For one because the companies like DHP that re-program PCM modules states it as a requirement. The revised programming mainly for fuel and spark is modified to take full advantage of mods such as intake and exhaust. In order to achieve the highest gains in horsepower premium fuel is specified as result. Also, it is not uncommon to see a modded L36 SII 3800 have a few degrees of knock retard (KR) so programming includes reducing spark retard/knock retard but in order to achieve that function properly premium (91+ octane) fuel is needed.