The increasing desirability in recent years of a detergent in motor gasoline to keep the carburetor throttle body free of deposits has accentuated the need for techniques to evaluate the clean-up performance of such detergents.
This paper describes Ethyl's approach to the evaluation problem. The basic procedure involves a comparative technique using a fixed photographic setup to obtain photographs of carburetor throttle-body deposits at various intervals during field service tests. In addition, carefully controlled dynamometer tests are used to determine deposit effects on fuel economy. Descriptions of the two test procedures and typical results are given.