Steady, fully burning wall fires were studied using alkanes (n-pentane,n-hexane, andn-heptane) burning in air. Completeness of combustion was characterized and evaluated for the three alkanes studied and was compared with results previously obtained for alcohols (methanol, I-propanol, and I-butanol) burning in air. When the alkanes were burred, with CO and CO2the principal carbon-containing products, less than 15% of fuel carbon was converted to product CO as opposed to CO2. Accounting for incomplete combustion in a numerical model that employs a one-step overall reaction led to less than a 5% decrease in burning rates and a drop in peak temperatures of less than 50 K. By contrast, when alcohols are burned, more than 30% of fuel carbon is found in product CO. Slightly lower temperatures in the free-convection boundary layers of the alcohols might account for some of this when the reactions concerning the conversion of CO to CO2are considered. However, reaction mechanisms currently favored for the combustion of methanol under fuel-rich conditions would account for a large part of the differences in amounts of CO formed by the alcohols and the alkanes.