What is the API rating recommended for use In Indian Royal Enfield Standard 350?
Dear Yahoo Users,
Kindly advice on the API rating recommended for use in Royal Enfield 350. I am using oil of multi-grade viscosity 20w50 API SF/CC,but I am doubted with the API rating. I don't think that in Royal En-field the engine oil has to meet the JASO rating as the clutch and the gearbox are in separate cavity. So its a car oil which is on operation. But the latest API rating is SM which is still hard to find in India.Brands like Castrol sell oil with API SL ratings but from my part of knowledge I hope those are meant for latest vehicles equipped with catalytic converters,the anti wear additives like Phosphorous and zinc has been reduced in ppm than the earlier ratings SG,SH,SJ.
Kindly advice.
20w50 is the correct multigrade oil and API "SL" will be fine, I have been using "SL" for three years and have had no problems.
Watch out for the API "SM", don't use it.
"SM" rated motor oils contain much lower levels of anti-scuff additive called "ZDDP" (Zinc Dialkyl Dithio Phosphate). On pushrod engines with flat tappet cams, such as Royal Enfields, the level of ZDDP may be inadequate to prevent rapid cam lobe and lifter wear. To avoid such problems, you should add a ZDDP additive to the crankcase, or use an oil that meets the previous "SL" service rating, or use diesel motor oil or racing oil that contains adequate levels of ZDDP to protect the camshaft and lifters.
So, luck is with you, you can get the "SL" oil which is good, but not the "SM" which would be bad, or you could find some 20w50 diesel motor oil (because it still has all the additives) and that will probably be the future choice for many bullet owners.
Thank you for your question, I learned a lot and discarded some previous ideas when I researched the matter.
