And your assertion that higher octane fuels have lower calorific values is only applicable to ethanol and methanol - but you talk about high octane petrol that has additives to reduce detonation - but that's wrong, so wrong.
High octane means less likelihood of detonation, not more.
Where did you state otherwise? Here: "[font=helvetica, arial, sans-serif]higher octane fuels have more additive's to make the fuel more knock resistant."[/font]
[font=helvetica, arial, sans-serif]And where is the evidence for this: "[/font][font=helvetica, arial, sans-serif] ive looked into using 20% meth 80% 99ron petrol. There are some huge benefits"[/font]
[font=helvetica, arial, sans-serif]The only place there are huge benefits is in allowing you to up your compression ratio to radical numbers that would result in dieseling and detonation in a sraight petrol engine - are you doing that as well? Otherwise you are REDUCING your overall calorific content and making your fuel 'weak'.[/font]
[font=helvetica, arial, sans-serif]I really don't think you have the least clue what you are talking about - you have taken a little tidbit from one place (methanol makes more power), a little bit from another place (high octane petrol has additives), some from another (additives can reduce detonation), more gleaned from somewhere else (calorific content of fuels) and come up with some mish-mash theory that just doesn't work.[/font]
[font=helvetica, arial, sans-serif]Here, let's make it simple. 95 Octane petrol has a calorific content of about 32MJ/kg, give or take. Methanol has a calorific content of 19MJ/kg.[/font]
[font=helvetica, arial, sans-serif]80% Petrol, 20% methanol = 1kg of fuel. 25.6MJ of petrol, 3.8MJ of methanol. Overall a calorific value of 29.4MJ - less than that of regular petrol. "[/font]adding meth will give more power" is a fallacy.
[font=helvetica, arial, sans-serif]Methanol isn't used for it's ability to give more grunt/kg, it is used for its ability to allow an engine that has been severely tuned to stay in one piece for longer than it would on petrol. Its resistance to detonation, its cooling effects, all add to a fuel that allows higher compression, thereby allowing more grunt. Methanol itself (and ethanol) is a pain in the arse as a fuel - it eats things (it's a great solvent!), it doesn't like cold (carbs/injectors freeze up), it needs to run ridiculously rich to be able to start at anything less than a dry, 20C day, it is very hygroscopic (pulls water out of everything - the air, especially.)[/font]