Oil, Shmoil

Newer motorcyles seem to be spec'd with fancier oils. My bike's manual tells me to use this kind of oil: Synthetic 10W-60 - JASO MA, MA2 - API SG.  Here's a little information from me learning what this all means.

Breaking this out, here's the four pieces of info:
Oil weight:  10w-60
Type: Synthetic
Standard #1:  JASO MA / MA2
Standard #2:  API SG

The oil weight and type are easy to understand. They're recommending a very wide range oil weight - 10w-60 - 10w when it's really cold, and 60w when it's really hot. On top of that, they are specifying full synthetic, which will survive better at higher temperatures than non-synthetic oil. Basically, the best of the best. So be it. On to standards.

"JASO" is a Japanese motorcycle manufacturer standard. It's the "Japanese Engine Oil Standards Implementation Panel". The JASO standard is divided between "2T" (subdivided into "FA", "FB", "FC", "FD") and "4T" (subdivided into "MA" [sub-subdivided into "MA1" and "MA2"] and "MB"). 4T is the more stringent one, MA the more stringent subcategory, and MA2 the more stringent sub-subcategory - i.e. the highest JASO standard would be 4T/MA/MA2 (the “4T” is normally left off). JASO 4T was introduced because modern automobile engine oils were having friction modifiers added to them, which was good for cars, but not Japanese motorcycles. Most Japanese motorcycles use a "wet clutch", meaning the clutch is in the same cavity as the rest of the engine and is lubricated by the same oil. As you would guess, clutches having an even more slippery oil doesn't work out very well. For a "dry clutch", where the clutch is in a separate cavity from the engine, this wouldn't have the same concern. On to API.

"API" is a standard from the "American Petroleum Institute". Their standards for gasoline engines start with an "S", followed by another letter. The first standard (now obsolete) was "SA". "SA" through "SH" are all considered obsolete, with the last few - "SJ" through "SN" - being the current standards. The API standards are more general than the JASO standards - they are for any gasoline engine - though they do seem to refer more specifically to cars, with each standard referring to an end date (i.e. use this oil for cars manufactured before year 199x). On to a summary of what we have so far.

So, adding these together, you have JASO MA/MA2, a motorcycle standard driven by Japanese motorcycles with wet clutches, and API SG, an obsolete automobile standard for cars before 1993. On top of it all, my bike has a dry clutch - the clutch lives in a separate cavity from where the engine oil lives - which makes the JASO standard a bit odd, combined with an obsolete automobile standard. Doesn't seem to add up, right? There's something else that seems to pull this all together, and that's zinc.

When zinc in oil is mentioned, it's actually referring to one of two ingredients - zinc dialkyldithiophosphate (ZDDP), or zinc di-thiophosphate (ZDTP). They're often used together, listed as ZDDP/ZDTP. The oil industry did some testing recently, and it was found that many older engines have a short time during engine startup where lubrication between certain metal parts is insufficient when lower amounts of ZDDP/ZDTP are in the oil. This is bad because the first moments when an engine is started is when the majority of the wear takes place. The downside of the additive, though, is that the phosphorous in the ZDDP/ZDTP creates carbon build-up, and also the premature demise of catalytic converters. Because of these downsides, the newer standards of oil have been phasing out the levels of ZDDP/ZDTP. This all started with the currently obsolete API standard of SH - making the use of the obsolete SG standard, with ZDDP/ZDTP levels that were not reduced yet, not so surprising.