A common misconception among those new to water methanol injection is the belief that all water methanol injection pumps are the same. In reality, there are significant differences in performance and reliability that customers should consider before making a purchase. Follow along as we go over the differences in water methanol injection pumps and why we carry three different pump options. 

In the water methanol injection industry, two primary pump brands have dominated the market over the last 20 years: Shurflo and Aquatec. Initially, all water methanol injection companies, including ours, utilized Shurflo pumps. However, over a ten-year period, every water methanol injection company, except Holley, transitioned to the Aquatec pump and for good reason.

We were the first to make the switch to Aquatec pumps, and for good reason. We were frequently replacing Shurflo pumps at our own expense due to seal failures occurring within the first three to six months. Given the high failure rate, the risk to our reputation, the potential for customer engine damage, and the mounting replacement costs, we had to find a reliable solution quickly.

Since Shurflo utilizes a 12v diaphragm pump, I conducted a search for similar pump technology and discovered Aquatec, another diaphragm pump company also based out of California.

An interesting note is that Aquatec’s founder and Chief Engineer, Ivar Schoenmeyr, previously worked at Shurflo. He has utilized his extensive experience to improve upon existing diaphragm pump designs, positioning Aquatec to offer high-performance alternatives to Shurflo products. We made the switch Aquatec and quickly the phone call related pump failures complaints came to end. 

Over the past 13 years of using Aquatec pumps as our water methanol injection pump manufacture. We now have three different pumps made for us. The PM75, PM115 and PM190. It all started with the PM75. This was the first pump we used by Aquatec.  

ProMeth PM75 is your standard issue 10 amp pump carried by most competitors. Theres nothing proprietary about it. It spins 1400 rpm @ 12 volts. It produces 190 psi at 1260cc/20 gph. 1.0 GPM open flow. Pressure begins to drop off as you increase jetting past 1260cc/20 gph. This is the pump many competitors use and claim to be the highest flowing pump on the market. It’s not. It’s actually the lowest flowing pump on the market.

Next, is the ProMeth PM115 is a 13.5 amp pump. Offers 50% increased flow over the standard issue PM75. It spins 1750 rpm at 12 volts. It produces 200 psi at 1890cc (30 gph). 1.2 GPM open flow. Pressure begins to lower as you increase jetting greater than 30 gph. 

The ProMeth PM190 is a 16.5 amp pump. It spins 2200 rpm at 12 volts. It produces 200 psi at 2520cc (40 gph). Pressure begins to drop off as you increase jetting greater than 40gph. We recommend a max of 3150cc total on this pump.