This work presents results and analysis of experiments on aldehyde and the regulated pollutants CO, HC, and NOx emissions, with varying engine-running parameters. An ethanol-fueled vehicle was tested in a chassis dynamometer, following a standard urban cycle test procedure. The test simulated a medium-distance trip in an urban area, of approximately 5.8 km, with a warmed-up engine. The running parameters tested in the experiments were mixture equivalence ratio, the additional air flow used in decelerations (dash pot), the fuel interruption function in decelerations (cutoff), and gear-change speed. The results pointed to a reduction on aldehyde emissions for lower gear-change speeds and for richer fuel mixtures.