The Pros and Cons of Water/Methanol Injection Systems


The Pros and Cons of Water/Methanol Injection Systems


Pro: Make More Power Without Using Race Gas

The ability to increase boost pressures to make more power requires more stable fuel, and that comes in the form of octane. Race engines use high octane fuel (sometimes 118 or higher, compared to 91 octane at the gas pump), and it’s very expensive. Water injection systems provide a way to effectively increase the octane rating of pump gas, providing a long-term cost-benefit to making reliable power gains.

Con: You’ll Need to Retune Your Engine

After installing a water/methanol injection kit on your race engine, you will need to have the engine retuned to take advantage of the benefits the system provides. If this isn’t done, the cooling benefits of the water injection kit will not be fully realized, and if the system is not set up properly it may negatively affect the engine.

Pro: Cost-Effective Boost to Horsepower

We all want more horsepower from our performance vehicles. The ability to create that extra power ‘on the cheap’ is one of the most significant pros of water/methanol injection systems. Going back to the cost of race gas, at the current price of around $20.00 per gallon or more, filling a 20-gallon tank with 118 octane race fuel for one weekend of racing is about the same cost of one WMI system. AEM Performance Electronics offers kits ranging from $400 to $600 and they include everything you need in the box to install it the right way, which you may not find with other options on the market.

Con: You’ll Have to Buy Methanol

Depending on the tank size in the system, water/methanol mixtures typically last about as long as the gas in the tank does. So, while the injection system may be a cost-effective piece of performance equipment, the fuel is consumable so you will need to buy it. One pro in this con, though, is that a 50/50 mixture of M100 methanol and distilled water nets the same benefits as using pure methanol and essentially cuts this consumable cost in half. More importantly, using pure methanol is dangerous and IS NOT recommended.

Pro: Decreases Inlet Air Temperatures and Exhaust Gas Temperatures

Engine combustion creates a lot of heat, and this heat is intensified in high-performance race engines using turbos or blowers. It’s common for temperatures to range anywhere from 200 to 300 degrees Fahrenheit when it comes to the air coming from your intercooler. However, water/methanol injection systems help keep that temperature down drastically. Cooler intake air temperatures also result in lower exhaust gas temperatures, which produce less wear and stress on your engine and are especially beneficial if your car has a turbocharger.

For any questions, comments, or concerns regarding water/methanol injection kits or other performance-enhancing modifications for your vehicles, reach out to the experts and specialists at AEM Performance Electronics. We have the knowledge to assist you with all your engine needs.


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