NEW PRO-BLEND CTX-2 UNDETECTABLE RACING FUEL ADDITIVE, ADDS 40 HORSEPOWER, 1 1 Gallon Bottle of Pro-Blend CTX-2 Undetectable Fuel Additive (Pro-Blend Part #1650). Can add up to 40 confidential horsepower. Produces strong mid-range torque. Designed to pass fuel tests. Very user-friendly and very consistent. A must for qualifying.