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Automotive glossary

Water-Methanol Injection

Water-methanol injection sprays a fine mist of water and methanol into the intake to cool the charge air and reduce knock.

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What is Water-Methanol Injection?

It is used mainly on tuned turbocharged engines. Some factory engines used water injection. A separate tank must be kept filled. Well-designed systems monitor flow and pull back boost if the injection fails.

How it works

The mist evaporates and lowers the intake temperature, allowing more boost or timing.

Why it matters for your car

If the system runs empty on an aggressive map, the engine can knock. Methanol is toxic and flammable.

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