SL 10w30 versus SJ 5w30

[Patman]

I seem to recall that when they released the specs for the SL formulations of oils, that they made the requirements stricter in order to qualify for 5w status. So if this is true, would a 10w30 oil in SL formulation perhaps have been able to qualify for 5w30 status under the old SJ requirements?

 

[Whimsey]

I could be dead wrong but unless you're talking about the fuel ecomomy tests for the SL oils and the cold cranking simulator test temps I don't think there is any different specs for 5W-30 and 10W-30. The cold crank test under SJ were 5W-30@ -25*C,3500cP. 10W-30@ -20*C,3500cP. For SL the 5w-30@-30*c, 6600cP. 10w-30@ -25*c,7000cP. Even measuring the SJ 5W-30 with the SL 10W-30 the cold crank @ the same temp(-25*C)the 10W-30 is still twice as large. I don't have any info on SJ fuel econconmy testing. I think the overall performance characteristics between a 5W-30 and 10W-30 are the same within their respective grades of SJ and SL. Whimsey