Straight weight synthetic oil

[kenmac]

The Kawasaki engine on my z turn calls for 30 or 10w30

 

[Copperhead]

Amsoil has several different offerings that are straight 30w oils, but also qualify as 10w30. From small air cooled engines all the way up to heavy commercial truck diesel varieties. The "10" before the w is just the winter flow rating. Same for 0, 5, 15, etc in front of any other multi oil. A 5w30, 10w30, or straight 30 are all 30w oils. They just have different flow ratings, which is achieved with viscosity improvers. But some, like the Amsoil stuff, the Group IV PAO synthetic they use in their 30w oil does not need any viscosity improvers to achieve a lower winter flow rating. Thus, it is a straight 30 but has a winter flow rating of a 10w30. And viscosity improvers are what breaks down in a oil. The oil itself doesn't break down. VI will shear under pressure. A straight 30w that also has a low winter flow rate and not use VI to do it is a very stout oil.

 

[davesl708]

Thanks for all the input. The chipper runs full throttle for hours while I chip and shred year round. I will get some straight syn and see if the consumption declines.