A vehicle gasoline engine converts gasoline into power so that the car can move, and lubricants are important for engines and also gear boxes. Manufacturers have produced numbers of engine oils, and gear oils for engines and gear boxes to SAE International Standards. Some products not only can improve the lubrication of both the engine and gear box but also can raise power of vehicle this can be easily seen in the advertisement declared by the manufacturers. To observe the lubrication performance, a multi-leveled (heavy duty) gear oil was added to a gasoline engine as the oil in the vehicle. The oil was checked at about every 10,000 kilometers. The engine was detailed disassembled, cleaned, and parts were measured. The wear of components of the engine parts were checked and recorded finally. Based on the experiment results, some gear oil seems possible to be used as engine oil in particular vehicles. Vehicle owners should change oil periodically in about every 6,000 miles (or 10,000 kilometers). Used car owners may change engine oil in even longer distance.
 Standard: J300_201501. Issuing: Fuels and Lubricants Tc 1 Engine Lubrication. Publisher: SAE International. Revised: 2015-01-20.
 Standard: J306_ 200506. Issuing: Fuels and Lubricants Tc 1 Engine Lubrication. Publisher: SAE International. Revised: 2005-06-14.
 Viscosity Classifications, Comparative Viscosity Classifications, tribology-abc.com.uk. http://www.tribology-abc.com/abc/viscosity.htm. 07.Aug.2016
 Amiyo Basu, Axel Berndorfer, Carlos Buelna, James Campbell et al., “Smart sensing of Oil Degradation and Oil Level Measurements in Gasoline Engines", SAE Technical Paper 2000-01-1366, 2000, doi:10.4271/2000-01-1366.
 Christopher D. DeDene, and Zhanping You. “The Performance of Aged Asphalt Materials Rejuvenated with Waste Engine Oil”. J. Pavement Res. Technol. 7(2):145-152.
 Cock, V. R. 1998. Laboratory Handbook for Mineral Oil and Organic Oil Analysis. Academy Press, London. 111-113.
 Accord Service Manual, (1994~1997). Engine Block. pp7-15~7-22.