Water-Methanol Injection for Mercedes-Benz — Cooling, Power & Reliability

Water-methanol injection (commonly called "meth injection") is one of the most effective ways to cool intake temps, prevent knock, and unlock more power in high-performance Mercedes-Benz engines — especially turbocharged models.

💧 What Is Meth Injection?

Meth injection sprays a fine mist of water and methanol into the intake tract or charge pipes. As the mixture evaporates, it absorbs heat from the air charge, significantly lowering intake temperatures. The result: reduced knock, more timing, and more power.

✅ Key Benefits

• Lower IATs: Cooler air means denser charge, more oxygen, and more power per PSI.
• Knock Resistance: Greatly reduces the chance of detonation under heavy boost or aggressive timing.
• Octane Boost: Methanol acts like a high-octane fuel additive — similar to running race gas.
• Cleaner Combustion: Water vapor steam cleans the intake valves and combustion chamber.

⚠️ Considerations & Myths

• It's not nitrous: Meth injection helps your current setup run more safely and efficiently — it doesn’t magically add 100hp on its own.
• Tune required: Most setups benefit from a proper ECU calibration to take advantage of the added knock resistance and timing headroom.
• Not just for race cars: Many daily-driven Mercedes AMGs benefit from meth — especially in warm climates or at elevation.
• No need to spray constantly: Setups are typically activated only under load/boost, not during normal cruising.

🔧 What You Need for a Complete Kit

• Methanol Injection Pump: High-pressure pump to deliver consistent spray.
• Nozzles & Lines: Sized for your power level and mounted in the correct charge pipe location.
• Reservoir: Holds the water/meth mixture — trunk-mounted or engine bay setups available.
• Controller: Boost-referenced or progressive controllers activate spray at set PSI or load levels.

💡 Platform-Specific Advice

Turbocharged Mercedes like the M157, M276, and M177 benefit greatly from meth. Even supercharged M113K cars see major gains in timing and IAT control. NA models benefit less unless running high compression or race setups.

📦 Kits Available from BenzUnited

We offer complete, proven water-meth kits tailored to Mercedes performance platforms. Our kits include high-quality pumps, weather-safe wiring, and platform-specific mounting solutions.

🚀 Final Thoughts

If you're pushing power or battling heat soak, meth injection is one of the smartest, safest ways to keep your engine happy and make consistent power. Just make sure the kit is installed correctly, the fluid mix is right, and the tune is optimized for it.

BenzUnited Parts is here to help you push your Mercedes further — reliably and efficiently.