^ Bump from hell ^
Note the linked article is lacking. There was one big error there, tuning to 'knock limit' but leaving the excess fuel ratio at levels that are not adequate for a WM50 engine to make maximum power, this is well founded and documented nearly everywhere.
If this was done correctly and the biggest caveat that I have been saying for decades! is you run the correct ignition system (CDI need only apply) then and only then can you assess true power potentials (of all fluids), and if it was done this way even they would find WM50 is superior in every aspect, and pure 'meth' is a rookies choice, mostly always picked due to other system short falls (misfire being #1)
You tune the engine, it does not tune you