Trends in motor gasolines: 1942-1981

Response of atmospheric lead to decreased use of lead in gasoline

“…Superimposed on the loading function are a series of atmospheric Pb measurements made in the period from the early 1960s through 1983. Measurements of aerosol Pb at Argonne National Laboratory south of Chicago (39) made from 1965 through 1981 coincide with the Pb source function as do aerosol measurements reported for 46 sites as part of the National Air Quality and Emissions Trends from 1975 through 1981 (47). The trends in wet atmospheric Pb fluxes observed at the urban Minneapolis, MN, site and the rural Marcell site also follow the source function.…”

A Historical Analysis of the Co-evolution of Gasoline Octane Number and Spark-Ignition Engines

“…Despite the damaging effects caused by the use of TEL in gasoline, TEL proved to be an effective and inexpensive octane improver that was widely adopted. Data in Figure 1 clearly show that during the fuel improvement age there was a direct dependence of engine compression ratio on fuel AKI, and Caris et al (1956) 1951-1968Kohl (1969 Heavenrich et al (1984) Patton (1962); Lucas (1967); Heavenrich et al (1984) Patton (1962); Lucas (1967); Heavenrich et al (1984) Heavenrich et al (1984) 1957-1973 Austin and Hellman (1973) Heavenrich et al (1984) Austin and Hellman (1973( ) 1942( -1981( Shelton et al (1982 Shelton et al (1982) Shelton et al (1982) 1982 - Dickson et al (1987 Dickson et al (1987) 1982-1997 CRC octane survey (1982 1983) 1930 -1992- Gibbs (1993 1975-2014 EPA LD Trends report (Alson et al, 2014) EPA LD Trends report (Alson et al, 2014) EPA LD Trends report (Alson et al, 2014) EPA LD Trends report (Alson et al, 2014) 1983 subsequently TEL concentration. Based on the wide adoption and reliance on TEL to improve gasoline AKI, the continued and persistent usage of TEL in gasoline illustrates the value that society and industry place on personal mobility.…”

“…For example, Figure 1 illustrates that fuel antiknock quality increases with TEL's introduction and subsequent increase in concentrations in motor gasoline. TEL also complemented new and improved refining processes throughout the mid-twentieth century, such as continuous process vacuum distillation, improved thermal reforming in the late 1920s and 1930s, catalytic cracking during World War II, and platinum reforming in the 1950s (Shelton et al, 1982), all of which also increased the antiknock qualities of motor gasoline. Although thermal reforming and catalytic cracking processes improved fuel AKI during the fuel improvement age, the full deployment of mature fuel improvement technology occurred during and after World War II, enabling the power wars age once World War II ended.…”

“…Additionally, although not illustrated in Figure 3, the complementary trends of decreased real value of fuel and fuel economy actually result in near constant consumer fuel cost on a real value basis (i.e.,~constant $/mi from 1951 to 1969). Note in Figure 3 that the AFR began to rise in 1967 in response to looming emissions regulation by the Environmental Protection Agency (EPA) and the California Air Resources Board (CARB) (2015) in 1970 and 1969, respectively (Shelton et al, 1982;United States, 1999).…”

“…Prior to the maturity of three-way catalysts, two-way catalysts were commonly used to control CO and HC emissions, but they required NOx emissions to be reduced in-cylinder by reducing in-cylinder temperatures while simultaneously reducing CO. The reduced compression ratio in this approach had an additional benefit in that it complemented the lower octane unleaded fuel, as seen by the rapid declines in Figures 2 and 4, which reduced the AKI of regular grade by two points from 90 AKI in 1970 to 88 AKI in 1974 (Neligan et al, 1961;Shelton et al, 1982;Dickson et al, 1987;Gibbs, 1993;United States, 1999; U.S. EPA (U.S. Environmental Protection Agency), 1973b). However, as NOx emissions control mandates became more stringent in the late 1970s, full catalysis of CO, HC, and NOx would be required to meet them, as future opportunities to operate fuel-lean would limit future fuel economy improvements (Kummer, 1980).…”