There's a 10 page post on tuners on water vs meth.. And the rep from devils own was in discussion. By the end he actually convinced himself that water/alcohol was a better choice.

I've always believed that if your just running a ton of boost and power on a built engine.. Where the engine isn't the limit , then meth is a better choice. It raises the octane level to suppress knock so you can run more timing and boost.

Water injection is more for running your engine past its limit. Eliminating knock so you can run way more boost and then tune for max power.

I think this is why people say max your tune out before you add meth. But with water.. You just add water and then raise boost and tune the car.

I'm more comfortable with water.. And I don't think I'll need more fuel any way. Not planning on making more then 32psi on my stock block.