Results, discussions and tabulated test data are presented for an emission program conducted with pre-1968 uncontrolled automobiles equipped with newly developed retrofit devices for reducing exhaust emissions. Three automobiles were selected to be used as test vehicles: a 1962 Chevrolet Biscayne with a 283 cu. in. engine and automatic transmission, a 1963 Chevrolet Impala with a 283 cu. in. engine and standard transmission, and a 1963 Ford Galaxie with a 289 cu. in. engine and automatic transmission. For the series of tests Iodolene 30 was used and fuel consumption was measured for each test by weighing the test fuel tank before and after each run. All tests were cold start. The following tests were performed on both the uncontrolled vehicle tuned to recommended manufacturer specifications and on the same vehicle after installation of the retro-fit device: (1) 1968 Federal procedure for exhaust emissions (FTP); (2) 9 cycles of the 7 mode Federal cycle used with constant volume sampling (CVS); (3) proposed 1972 LA4-S3 test cycle with constant volume sampling (CVS).