The recent referencing to nitrogen enrichment in motor gasoline has to do with the deposit control additive that is required by federal law to be used in the gasoline. All commercial deposit control additives, which help control deposits in injectors or carburetors and on intake valves and intake ports, contain nitrogen. Nitrogen enrichment is nothing new. But, nitrogen alone does not provide the engine keep-clean and cleanup necessary to help with good performance, maintaining fuel economy, and keeping emissions low. The basic polymer in the deposit control molecule also plays an important role. The molecular structure of polymer also can affect the amount of combustion chamber deposits that form and possibly affect intake valve sticking. Some deposit control additives contain several components to optimize performance. The concentration of the deposit control additive in the gasoline is another critical factor. So, just promoting nitrogen enrichment doesn’t provide a meaningful assessment of a deposit control additives performance.