HEET (yellow bottle) is methanol. Denatured alcohol is usually ethanol with some methanol or other non-drinkable substances mixed in.
So what is the difference?
methanol has about 4.6 kcal/gm
ethanol has about 6.4 kcal/gm
Ethanol has about a third more energy available per gram than HEET. So your denatured alcohol ( depending on how pure it is ) probably boils water a little quicker than HEET would. However I would guess that it isn't a big difference given all the variables with alcohol stoves.
Stick with your denatured alcohol.
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