E85 Fuel Tester Tool

The Holley E85 Fuel Tester Tool is a precision instrument designed for performance enthusiasts, mechanics, and tuners who work with ethanol-blended fuels in high-performance engines. This portable tester quickly and accurately verifies fuel alcohol content in the field, eliminating guesswork when diagnosing fuel quality issues or confirming proper E85 pump compatibility. Whether you're tuning a carbureted engine, troubleshooting a fuel system, or validating fuel delivered from a supplier, this tool provides immediate visual confirmation of ethanol concentration levels.

Built from durable clear plastic, the E85 Fuel Tester Tool uses a simple hydrometer principle to measure fuel density and translate it directly to ethanol percentage on an easy-to-read scale. The transparent construction allows users to observe fuel behavior and read results accurately across the 70–100 percent ethanol range—the critical window for E85 compatibility verification. Its compact design (approximately 6.3 inches in length) fits easily in a service kit, toolbox, or vehicle, and the lightweight construction (0.09 lbs) ensures portability without sacrificing reliability or accuracy.

This tester is essential for anyone running or considering E85 fuel systems, particularly in modified or competition vehicles where fuel quality directly impacts engine performance and tuning stability. Mechanics and fuel system specialists rely on this tool to validate fuel batches before installation, while dyno operators and tuners use it to confirm fuel specifications during calibration. The straightforward operation requires no batteries, calibration, or complex setup—simply fill, observe, and read the result instantly. Holley's reputation for precision fuel system components ensures this tester meets the accuracy demands of professional and serious amateur applications.