4. Conclusion

In all countries where reliable lubricant statistics are available, the share of motor oil consumption is by far the largest, ranging from a third to over half of all lubricants. However, in the industrialized countries of Western Europe and North America, not only the tonnage but also the relative share of motor oils has been declining since 1999, as shown in table . This trend is not due to the continuing increase in the number of vehicles on the road, nor to the increase in average distances travelled, as shown by the rise in fuel consumption. It is due to the considerable lengthening of oil change intervals for modern engines (20,000 to 50,000 km on passenger cars and up to 100,000 km, and sometimes more on trucks), as well as to the reduction in engine oil consumption (tighter rings and seals, less volatile oils...).) in order to reduce pollutant emissions from the...