Hi,
I am trying to get better understanding how VII work, and what shearing does to the oil. What's the advantage of 10w dyno against 5w dyno.
Looking at UOA for dyno oils, I can see that 10w30 is holding up the viscosity much better. After few kmiles, 10w30 is (more often than not) still in w30 area (around 10cSt). And 5w30 often shears down to something like 7.5-9 cSt, becoming 5w20.
Seen this table several times on different web pages (for example here):
SAE.............Kinematic
Viscosity.......(cSt)
................100° C Min
0W..............3.8
5W..............3.8
10W.............4.1
15W.............5.6
20W.............5.6
25W.............9.3
Let's imagine that we have removed all VII from 5w30 and 10w30 (both dino) oils. In another words, it sheared down completely to the "straight 5" and "straight 10". What will be the viscosity at the operating temperature in both cases? According to this table, it will be almost identical: 3.8 or 4.1 cSt. Is anything wrong with this data? If so, what would be the correct numbers?
(I'm quite new to BITOG, so if I am asking something obvious, please point me to the right direction...)
I am trying to get better understanding how VII work, and what shearing does to the oil. What's the advantage of 10w dyno against 5w dyno.
Looking at UOA for dyno oils, I can see that 10w30 is holding up the viscosity much better. After few kmiles, 10w30 is (more often than not) still in w30 area (around 10cSt). And 5w30 often shears down to something like 7.5-9 cSt, becoming 5w20.
Seen this table several times on different web pages (for example here):
SAE.............Kinematic
Viscosity.......(cSt)
................100° C Min
0W..............3.8
5W..............3.8
10W.............4.1
15W.............5.6
20W.............5.6
25W.............9.3
Let's imagine that we have removed all VII from 5w30 and 10w30 (both dino) oils. In another words, it sheared down completely to the "straight 5" and "straight 10". What will be the viscosity at the operating temperature in both cases? According to this table, it will be almost identical: 3.8 or 4.1 cSt. Is anything wrong with this data? If so, what would be the correct numbers?
(I'm quite new to BITOG, so if I am asking something obvious, please point me to the right direction...)