Do a UOA now, or wait to do the next fill?

[INDYMAC]

My 2003 G35 is coming up on a 60K oil change (5K OCI). There is PP 5W30 (old formula) in it now. I plan to replace it with PP 5W30 (new formula). Should I do a UOA on the old or new, or both (ouch$)? It's been 30K since my last UOA.
BTW- I understand that the new formula is Group III, but what was the old?

 

[Ken42]

Old formula was A group V gas to liquid base.
I would do a test on the old and see how the engine is doing.

 

[dave1251]

If indeed you have the old stock your UOA maybe skewed if you do it on your next OCI. Do to change in formulations.

 

[427Z06]

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My 2003 G35 is coming up on a 60K oil change (5K OCI). There is PP 5W30 (old formula) in it now. I plan to replace it with PP 5W30 (new formula). Should I do a UOA on the old or new, or both (ouch$)? It's been 30K since my last UOA.

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It would be interesting to see a UOA on the old formula, not many of those. Did you use the old formula prior to this OCI?

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BTW- I understand that the new formula is Group III, but what was the old?

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Ethylene-alphaolefin polymer (EOP). EOP is synthesized from ethylene, propylene and butene using a single-site catalyst, and the reaction products from the process exhibit comparable physical and chemical properties to PAOs. Even more, the feed stocks and manufacturing costs are significantly lower for EOP than PAOs.

 

[INDYMAC]

This is the 2nd OCI on the old formula (EOP). I think I will have it analyzed as recommended to see how the engine is doing.
Why did Pennzoil change the formula to the "new, improved" Group III? The EOP seemed to be working well and was cheap?
I'm confused about the comment "we don't have many UOA's of the EOP formula". I thought that's all we had so far.

 

[Steve S]

Unless you suspect a problem do it now .If there are no problems there is no need to do another uoa at the next oil change.

 

[427Z06]

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Why did Pennzoil change the formula to the "new, improved" Group III? The EOP seemed to be working well and was cheap?

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Johnny probably has a better answer to this question. However, I suspect that since they only had a pilot plant producing the basestock, unless they expanded the economies of scale, they would never be able to compete with inexpensive Group III basestocks most everyone else was using, even Mobil 1.

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I'm confused about the comment "we don't have many UOA's of the EOP formula". I thought that's all we had so far.

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I didn't actually count them. So my bad if I'm wrong.