Mercury - Fuel Level Gauge White Face 2-1/8" (52 mm) 79-8M0052865. Overview. The Mercury Fuel Level Gauge (79-8M0052865) gives you a quick, accurate view of your fuel status every time you turn the key. Designed with a white face, black numerals, and a glass lens, it delivers clean, easy readability that matches other Mercury OEM gauges perfectly. It fits a standard 2-1/8" (52 mm) dash opening and integrates smoothly with SmartCraft-compatible systems depending on your engine model and fuel sens