learn that synthetic diesel engine oils reduce the demand on oil stocks.Ĥ. recognize that synthetic diesel-engine oils extend crankcase oil drain intervals and the use of these oils can save energy by reducing internal engine friction.ģ. be aware of the differences between natural and synthetic diesel engine oils.Ģ. To understand how longer crankcase drain intervals can save energy.ġ. To understand the use of synthetic oils in diesel engines. 90,000 Mile Diesel Engine Oil Changes? 90,000 MILE DIESEL
