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Water Injection




























Water Injection

When water/methanol injection is properly used in a gasoline engine the combined fuel behaves like 120 octane. A high octane rating doesn't really provide an increase in power. However, it permits an engine to produce more power. An increase in gas mileage is an indirect result of leaning out the fuel and advancing the ignition timing.

The water/methanol injection is best used with a customizable engine computer reflasher. This would enable the ignition to be advanced (about 10-15 degrees) and stoichiometry to be leaned out to 12.0 to 12.5 at wide open throttle. Different cars will have different results. I would expect 1-3 mpg gain (5-15%).

The increase in octane rating from the water/methanol injection means that a vehicle that requires 91 or 93 octane can safely run 87 octane and still have a 100+ octane rating. And that difference in cost will easily pay for a gallon of washer fluid.

To help cool a stressed combustion chamber, auto manufacturers typically squirt extra gasoline in the engine. This extra gasoline is not burned; instead it is vaporized when it absorbs heat. It's simple and easy to do from a manufacturing standpoint. However its a poor use of gasoline. When methanol is used in place of the extra gasoline to cool the combustion, the methanol is three times more effective than the gasoline. Water is six time more effective than the gasoline. When properly mixed, the methanol and water cool combustion and raise the octane rating.

Water absorbs six times the heat gasoline does when vaporized in a mixture. The water does not burn. It becomes steam. Only so much can be injected before it starts to quench the combustion. Too much water will put out the fire. If pure water is injected, then the quantity should be half of what would be injected if a 50/50 mix of alcohol and methanol were used.

Window Washer Fluid
Most window washer fluid contains 30% to 36% methanol and is rated for -25F to -20F. Mixing in a bottle of HEET can raise the methanol percentage closer to 50%. Window washer fluid is the simple solution. This is what I pour in the washer fluid tank of the test car. The washer fluid tank serves as the reservoir for the water/methanol injection and for cleaning the windshield.

Proper Mixture
The ideal mixture is 50% water by weight (not volume) and 50% methanol by weight (not volume). This can be purchased from specialized dealers or mixed by hand from distilled water and methanol purchased at a hardware store.
Washer fluid with a freezing point higher than -20F contains very little methanol. Although it isn't harmful, it's not the best choice.


Do NOT Use:

Pure methanol
AKA: methyl alcohol, wood alcohol. This is not safe. It is flammable. The flame is invisible. It is toxic. Pure methanol is acidic and corrodes the protective oxide layer in aluminum. The boiling point of methanol is 148.2F, which means it can boil in the manifold before reaching the combustion chamber. When the methanol becomes a vapor it can easily combust causing an invisible flame. Methanol has about 1/8 the energy content of gasoline.

Washer fluid rated for -30F or -40F
This contains anti-freeze (propylene glycol), that will harm the engine.

E85 is not methanol injection.
E85 is a mixture of 15% gasoline and 85% alcohol. The energy content in alcohol is less than half that of gasoline. So more alcohol is required to compensate for the lack of energy content. There is no cooling benefit because it does not contain water.


Other Info

Latent heat (Joules per gram): The amount of heat absorbed by a chemical substance during a change of state (liquid to gas).
Water: 2260 J/g
Methanol: 1050 J/g
Gasoline: 350 J/g

Density in kilograms per meter cubed (kg/m^3) (around 120F)
Water: 988 kg/m^3
Methanol: 765 g/cm^3
Gasoline: 740 kg/m^3

Energy content in megajoules per kilogram (MJ/kg)
Gasoline: 43 MJ/kg
Diesel: 47 MJ/kg
Methanol: 20 MJ/kg


Let's Review:
• Water/methanol injection by itself doesn't improve gas mileage or make more power.
• Water/methanol injection can raise the octane rating to about 120 octane when properly used.
• A high octane rating means that less fuel and advanced ignition timing can be used.
• It is the reduction of fuel that results in better gas mileage and more power.
• A 50/50 mix of water and methanol by weight is best.
• Window wash fluid rated between -25F to -20F works well too.


See the water injection system on the test car.


Step 3: Improved Maintenance
Engine Oil
Oil Filters
Ceramic Additive
Air Filters
Spark Plugs
Tire Selection
Wiper Arm Adjustment


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