API-SN (Introduced October 2010)
Category SM were introduced in October 2010 for 2011 and older vehicles, designed to provide improved high temperature deposit protection for pistons, more stringent sludge control, and seal compatibility. API SN with Resource Conserving matches ILSAC GF-5 by combining API SN performance with improved fuel economy, turbocharger protection, emission control system compatibility, and protection of engines operating on ethanol-containing fuels up to E85
For bikes=Not recommended//Resource conserving oil have extra additives which hamper bike's lubrication in the long run,,also added friction modifiers cause wet clutch slippage(not recommended for Jap scooters)
API-SM (Introduced on 30 November 2004)
Category SM oils are designed to provide improved oxidation resistance, improved deposit protection, better wear protection, and better low-temperature performance over the life of the oil. Some SM oils may also meet the latest ILSAC specification and/or qualify as Energy Conserving. They may be used where API Service Category SJ and SL earlier categories are recommended.
For Bikes=Not recommended if energy conserving,,
API-SL(2001 Gasoline Engine Service):
Category SL was adopted to describe engine oils for use in 2001. It is for use in service typical of gasoline engines in present and earlier passenger cars, sports utility vehicles, vans and light trucks operating under vehicle manufacturers recommended maintenance procedures. Oils meeting API SL requirements have been tested according to the American Chemistry Council (ACC) Product Approval Code of Practice and may utilize the API Base Oil Interchange and Viscosity Grade Engine Testing Guidelines. They may be used where API Service Category SJ and earlier categories are recommended..
For bikes(Higly recommended--->>>Devilskreed choice award<<<)Non energy conserving good for bike with not extra added friction modifiers but low ZDDP(Zinc-phosphorus quantity than predecessors' i.e(0.05%-- ZDDP is a last resort protection against metal-to-metal contact).However, this in itself may not be a problem since normal operation of a motorcycle on the street would never result in metal-to-metal contact any more than it would in your automobile. Remember these SL oils meet the most demanding protection requirements of modern, high-reving, powerful 4-stroke automobile engines (among others). And there is no reason to believe the lubrication requirements of street motorcycles is measurably different.
API-SJ (1997 Gasoline Engine Service)
Category SJ was adopted in 1996 to describe engine oil first mandated in 1997. It is for use in service typical of gasoline engines in present and earlier passenger cars, vans, and light trucks operating under manufacturers recommended maintenance procedures. Oils meeting API SH requirements have been tested according to the American Chemistry Council (ACC) Product Approval Code of Practice and may utilize the API Base Oil Interchange and Viscosity Grade Engine Testing Guidelines. They may be used where API Service Category SH and earlier categories are recommended.
ForBikes=COmpatible and recommended..
API-SH Obsolete For model year 1996 and older engines.
For bikes=Compatible but there are better alternatives
API-SG Obsolete For model year 1993 and older engines.
For bikes=Compatible but there are better alternatives
API-SF=Chacha oil--recommended on all pakistani bikes..Can be used but there are WAY WAY better alternatives
Synthetic or Conventional
All motor oils have several special additives formulated into the oil to protect from corrosion and wear, plus detergents to keep combustion products in the oil. For normal (non-extreme) use, "dino" oils protect as well as the synthetic oils. However, if you plan to race, run at extremely high temperatures, or plan to extend oil-change intervals, or simply want the best, then a synthetic or semi-synthetic may be your best choice.
By far liqui-moly is the best available mineral oil in 20w50 Viscosity ratings..
I am still looking for a good fully-semi synthetic oil..Till now found none..Zic oils have a history of causing ruckus in Honda 100CC's and above to i tend to stay away,.
