Mixing RON95 with RON97

[wongsl]

in general most octane boosters aren't worth it. i've tried quite a few of them. they don't come close to their claims. maybe if u pump 89/91/93 and put a bottle in, it has more effect, but 95 or 97, barely. Pumping 97 directly has the most obvious effect. mixing doesn't yield the average of the two. it is always lower.

what is definitely true.. different petrol stations even same brand will give u different quality of fuel. i find the more stable one to be Petronas. new petrol station also normally you can confidently go in and expect what you pay for.

97 or 95 tune? if you have a tuneable ecu, then there are two things to consider. first, u should tune at 95, then switch to 97 and tune, then see how much power difference u get. u don't have to go on a dyno to know, u just need to look at how much difference you have your timing table. if u have minimal gains in timing, u may as well save $ and go for 95. and the savings is pretty a lot too mind u!
if the timing difference is >5degrees at mid to high rpm range, then i would say it is worth to consider going 97.

for my low compression 2mm head gasket on 4G63T, 95 and 97 made a world of difference. 95 is so bad that it makes u sick :P