A new Volvo Penta carbureted 4.3 GL engine underwent emissions and dynamometer durability testing from break-in to expected end of life using an accelerated ICOMIA marine emissions cycle and E15 fuel. Only ethanol content was controlled. All aging used splash-blended E15 fuel. Exhaust emissions, exhaust gas temperature, torque, power, barometric pressure, air temperature, and fuel flow weremeasured at five intervals using site-blended E15 aging fuel and certification fuel (E0). The durability test cycle showed no noticeable impact on mechanical durability or engine power. Emissions performance degraded beyond the certification limit for this engine family, mostly occurring by 28% of expected life. Such degradation is inconsistent with prior experience. Comparisons showed that E15resulted in lower CO and HC, but increased NOX, as expected for non-feedback-controlled carbureted engines with increased oxygen in the fuel. Fuel consumption also increased with E15 compared with E0. Throughout testing, poor starting characteristics were exhibited on E15 fuel for hot re-start and cold-start. Cranking time to start and smooth idle was roughly doubled compared with typical E0operation. The carburetor was factory-set for lean operation to ensure emissions compliance. Test protocols did not include carburetor adjustment to account for increased oxygen in the E15 fuel.