3. Comparative engine oil and fuel consumption

Figure 2 shows the trend in average motor oil consumption between 1955 and 2001, compared with the corresponding consumption of automotive fuels (gasoline + diesel) for the French domestic market. The quantities of motor oils consumed include first fill-ups, oil changes, top-ups, leaks and miscellaneous losses. Despite a significant reduction in vehicle fuel consumption, relative oil consumption has been divided by 4 in 45 years. These gains are due both to technological improvements in engines (metallurgy, geometry, dimensional precision, surface...