What oil API rating is suitable for a diesel engine?
What oil API rating is suitable for a diesel engine? For most diesel engines operating in New Zealand, an SAE 15W-40 multigrade Diesel Engine Oil will be suitable. This allows starting down to -20o C and continuous operation up to ambient temperatures of 40o C. As well, SAE 10W-30 multigrade DEOs are available. What is the most current API service classification for diesel engines? The current API Service Classification is SN The suffixes (0, 5, 10, 15 and 25) followed by the letter W designate the engine oil's "winter" grade. Look to your owner's manual. It specifies the viscosity grade...