1. National Highway Transportation Administration [Internet]. Available from: 〈https://www.nhtsa.gov/〉.
2. United States Enviromental Protection Agency. Available from: 〈https://www.epa.gov/〉.
3. Mock P. Emission Standards for Passenger Cars and Light-Commercial Vehicles in the European Union. ICCT Policy Updat [Internet]. 2019;(January 2019). Available from: 〈http://www.europarl.europa.eu/news/en/press-room/20181218IPR22101/curbing-co2〉-.
4. Effects of lubricant composition on fuel efficiency in modern engines;Inoue;SAE Trans,1995
5. The effect of 0W-20 low viscosity engine oil on fuel economy;Tanaka,2010