WFAA looked into the state-supported diesel additive said to have the ability to cleanse the air and improve fuel mileage. Their investigation found that not only was the product's effectiveness overstated, but the additive, known as "Green Plus," was actually "nearly pure rubbing alcohol." Usually, high-grade isopropyl alcohol sells for $25 a gallon, but the Texas state government was being charged more than $600 a gallon by the California-based company that was selling this additive. When confronted, "The company ultimately acknowledged their product was essentially rubbing alcohol, but claimed the additive had a secret catalytic blend of virtually immeasurable amounts of trace metals, accounting for the higher cost." Tests by fuel emission testing labs "revealed the product had little or no impact on reducing diesel emissions." In addition, companies that gave testimonials about Green Plus admitted their claims were false. As a result, there was a federal investigation, and the Texas government eliminated Green Plus from its list of approved fuel additives.