Water Methanol injection – What is the go?

Over the past 20 years, we have seen water / methanol injection fitted to performance cars, it is often seen as an “inexpensive power addition”. – Let’s consider the pro’s & cons of installing water / methanol injection (W/M) into your “street” car:

How it works: 

Methanol is a fuel, it has been used in different motorsport applications over the decades. It has certain advantages & disadvantages when it comes to practical use in a “street car”.

Methanol mixed with water & then injected into the intake system of a vehicle can have the same effect as raising the octane level of the fuel by 20-25 octane numbers (MON).


More power, efficiency & a cooler combustion cycle. When the vehicle is properly tuned for the additional octane, large increases in power can result.


It is illegal for road use in Australia (see below)

If you have an interruption in W/M injection during high loads, engine damage can result very quickly. This can include running out of W/M, pump failure, blocked nozzle, surge when cornering, etc.

Your mix of W/M should be the same every time, especially if your car is tuned for the specific octane. It is common for the end-user to “mix their own” W/M mix to save money on pre-mixed solutions.

W/M burns even when mixed 50/50 – please see this test: https://youtu.be/W0AmMFlXWE4

We do see that some “premixed” W/M solution has a content of 49% Methanol & 51% water to give a nonflammable mixture. There is no end-user tool for accurately testing the mix of W/M to see if you have a “flammable” or “nonflammable” mix.


We have seen the effects of when W/M goes wrong. From engine bay fires where hose nozzles come loose and spray the mixture over hot items, to a near fatal drag strip accident where a crash resulted in the test driver being covered in methanol from a regular installed kit (they added pure methanol into the tank for the drag strip). 

Imagine having an accident & covering yourself, passengers or family in a flammable solution? And what will your insurance company say on inspection of your vehicle?


Because W/M is injected into the intake tract of a car, it is classified as fuel – you can argue that it could be just water injection, but an engineer can not control what you put into the tank. It falls into the same category as fitting a surge tank; Installing a Liquefied Petroleum Gas (LP Gas) fuel system; and Installing a Natural Gas (NG) fuel system.

Your installation would need to follow NCOP9 for fuel systems.


And then be mod plated by a certification engineer. You will find you will then be able to insure your vehicle legally when it is mod plated.

Have we ever seen a legal, mod plated W/M injection system? No & multiple engineers we work with on modifications have not either to date.

Australia’s fastest Golf runs methanol injection – race track only! https://www.instagram.com/stock7r/