Oil

[Ken S]

I'm dusting this post off... So here's another oil question for you folks. I just had my first oil change done at the dealer after breaking 1000 miles. Normally, I do all my changes myself, but this one was free so I figured what the heck. Anyway, after I got my car back and glanced at the RO I realized they had used 10W30 instead of 5W30. Do I need to be concerened? It's s summer time here so morning temps are around 60 degrees. 10W30 and 5W30 should flow about the same, correct? Ken

[Weasel]

I have an 04 Acura TL and posted this on an Acura forum I used to hangout at. The magazine in question reflects the company's policies. "Got my Acura Style magazine today and within the pages of this fine publication is a Q&A section in which readers write in Acura related questions. One question of note is a reader's concern about when to change the factory fill oil on his new 2003 TL with 1800 miles. (A little dated but still relevant). His dealer advised against changing the oil before 3750 miles, "because it has chemicals that must process through the engine thoroughly. The "expert" agreed with this advice and added "The oil originally installed at the factory is a very special blend normally referred to as break-in oil. It contains special additives that are beneficial to the early stages of an engine's life." It goes on to advise to stick with the manufacture's drain interval afterwards"

[JoeGT]

[quote name='Ken S']I'm dusting this post off... So here's another oil question for you folks. I just had my first oil change done at the dealer after breaking 1000 miles. Normally, I do all my changes myself, but this one was free so I figured what the heck. Anyway, after I got my car back and glanced at the RO I realized they had used 10W30 instead of 5W30. Do I need to be concerened? It's s summer time here so morning temps are around 60 degrees. 10W30 and 5W30 should flow about the same, correct? Ken[/quote] Ken, you've got nothing to be worried about. In general, the only benefit of 5w-30 over 10w-30 is that you should get a slightly better fuel economy. According to API J300 specs, the 5w must have both lower pumpability viscosity @ a lower temperature AND a lower pour point. The former translates to less viscosity/friction during startup and when the oil is relatively cool, the latter means it won't gel up/solidify until it gets VERY cold. FYI, one bonus of a 10w-30 over 5w-30, assuming the same type of base oil used, is that 10w-30 will need less "viscosity boost" from the Viscosity Modifier additive (or to say it another way, the base oil provides more of the viscosity at high temperature). This is beneficial because base oil is always far more shear stable than any of the Viscosity Modifers. Over time, and under high shear conditions, the VMs break down, and if the oil relied heavily on them to reach the target high temperature viscosity, then the oil vicosity could drop significantly. NOTE, the reason this comparison only works for oils w/ the same base oil types is that higher quality base oils (highly processed mineral oils and synthetic oils) have naturally relatively LOW cold viscosity while STILL having relatively HIGH hot viscosity (which means much less VMs are needed). I hope this answers your questions w/o going too much overboard.