Originally Posted By: Joe90_guy
Typically a European 5W30 is limited by 3.5 min HTHS. A lot of these oils are formulated with Shellvis VIs which have good polymeric efficiency but relatively poor HTHS performance. Typically a 5W30 will have a high KV100 to make the 3.5 min HTHS (12.0 cst isn't uncommon). These oils aren't limited by KO30 shear.
The corresponding 5W40 will almost certainly be limited by KO30 shear before it's limited by HTHS (3.7 min if API specs are part of the spec claim). Even with Shellvis, you're probably talking about an actual 3.9 HTHS if the oil is going to meet 12.5 min after KO30.
Hope this helps...
There's some new terminology for me.
KO30 = Kurt Orbahn test, 30 passes?
Isn't the standard KO test 90 passes?
Typically a European 5W30 is limited by 3.5 min HTHS. A lot of these oils are formulated with Shellvis VIs which have good polymeric efficiency but relatively poor HTHS performance. Typically a 5W30 will have a high KV100 to make the 3.5 min HTHS (12.0 cst isn't uncommon). These oils aren't limited by KO30 shear.
The corresponding 5W40 will almost certainly be limited by KO30 shear before it's limited by HTHS (3.7 min if API specs are part of the spec claim). Even with Shellvis, you're probably talking about an actual 3.9 HTHS if the oil is going to meet 12.5 min after KO30.
Hope this helps...
There's some new terminology for me.
KO30 = Kurt Orbahn test, 30 passes?
Isn't the standard KO test 90 passes?