GC in a wet clutch?

[sunruh]

my street bike has a catalytic converter. quite a few do. so your point, isn't.

 

[Mike_dup1]

A whole lot more don't.

 

[Tree Hugger]

Originally Posted By: Mike_dup1
Most auto oils now have lower zinc and phosphorus (high pressure) additives in their oils. This was done to increase catalytic converter life in automobiles. Most "motorcycle" oils have a much greater percentage of high pressure additives in their oil for this reason.


In order to comply with new standards intended to avoid damage to catalytic converters, oil blenders were compelled to reformulate their additive packages using less of the cheap and effective ZDDP, and more of better, but more expensive, additives.
However, they found they can still produce the older, cheaper, formulations and sell that oil at a vastly higher price as 'motorcycle oil' to the gullible.

 

[Craig750]

What are the new additives you refer too?

 

[Tree Hugger]

I did read what one oil company had changed to once, but I don't remember. Or care. The key thing is that the performance of SM oils is better, however the 'wizards' achieve it. I believe specific add packs are not only proprietary, but also change as ingredient prices change... There are many other ways to achieve compliance with the standards, ZDDP is only a conveniently cheap one.

 

[mechanicx]

Some motorcycle oils do have higher zddp levels, like Mobil 4T has racing oil levels ~1600 ppm ircc. I do generally think SM is better and SM doesn't necessarily mean lower phopshorus and zinc. I think most HD oils are SM 1200 ppm and non EC and I think this is probably as good or better than the run of the mill motorcycle oil and adequate for anything short of a sportbike on a racetrack. I'd think if a scooter had a cat and says only to use non-EC 10W30 then the engine would be designed to run on lower phosphorus oils.