Test Tube used to find the ethanol/alcohol percentage in gasoline.
Directions: Step 1: Add water to the water line. Step 2: Add gasoline to the gasoline line. Step 3: Replace cap and shake vigorously Step 4: Stand vial vertically with cap upright for 10 minutes. Step 5: Locate the gasoline/water separation line and read scale. The separation line will indicate the percentage of alcohol, if present.