I don't know what an "esky" is.
A Methanol and Internal combustion engine primer.
Methanol has less energy content per volume than gasoline. To achieve the same power you have to use about 1.75 times as much of it ( or more) as gasoline.
Because of this, carbs jetted to use gasoline, must have much larger metering orifices for it to run properly, and no real power gain.
Methanol combusts at a much lower temperature than gasoline. As such, it has a higher octane rating. Adding to gas, therefore boosts your octane rating. (You can advance your spark for small power boost.) Engines running straight Methanol can be built with much higher compression ratios, and make a lot more more power per displacement of the engine, with little fear of pre-ignition or detonation. Endurance races will need a larger fuel tank than gas fueled ones.
If your engine is running rich or you have adaptive carburetion/fuel injection, you can add about 10% methanol to your gas. This will lean out your burn some and allow your engine to pollute less. It won't improve your mileage any, though. Well, it will improve your gas mileage, but not your overall fuel consumption.
Methanol is very hygroscopic (absorbs water). This is a storage problem if it has been exposed to humidity in the atmosphere. Water in the fuel does not add energy to the burn, and lowers power output when running on straight methanol. It won't matter if you are just diluting gas, due to the low dilution rate. If properly stored, in a non-corrosive container, high purity methanol remains stable for many many years.
Methanol with water in it forms a corrosive chemical that erodes aluminum in the fuel system. Water itself also leads to corrosion.
Some types of rubber seals that survive well with gasoline exposure, deteriorate with exposure to Methanol. They "dry out", shrink, and begin to leak. Accelerator pump diaphragms get brittle and crack. Replacement becomes necessary.
Exhaust temps using methanol are lower. Exhaust systems corrode faster as the gases contain alkali and more water vapor, and the temps are lower, reducing the ability to rid the exhaust of water by vaporization. Both alkali and water advance exhaust system corrosion. Using stainless steel helps.
This enough?
Cheers,