Delvac 1 5w-40 ESP in a 4.7 tundra

[Jmoney7269]

Scored a major good deal on some mobil delvac 1 5w40. $27 a gallon plus the $13 mail in rebate, $14 for a top quality oil is a win in my book. Anyways on the website it says that it can be used in mixed fleet gas vehicles. Since I use this vehicle all the time pulling stuff and basically driving It like I stole it, I figured this stuff cant hurt. Its whole life has been on EP 5W-30 with 10k-15k OCI. First thing I immediately noticed was the startup lifter noise dissipated and is now non existent. To me it even seems to idle a little smoother.....
So since this is a robust top notch diesel oil, can I run it at the same OCI as when I was using the EP?

 

[Garak]

Yes, perhaps even longer, verifiable by UOA.

 

[dnewton3]

Originally Posted by Jmoney7269
Scored a major good deal on some mobil delvac 1 5w40. $27 a gallon plus the $13 mail in rebate, $14 for a top quality oil is a win in my book. Anyways on the website it says that it can be used in mixed fleet gas vehicles. Since I use this vehicle all the time pulling stuff and basically driving It like I stole it, I figured this stuff cant hurt. Its whole life has been on EP 5W-30 with 10k-15k OCI. First thing I immediately noticed was the startup lifter noise dissipated and is now non existent. To me it even seems to idle a little smoother.....
So since this is a robust top notch diesel oil, can I run it at the same OCI as when I was using the EP?


The only thing it will "hurt" is your fuel mileage due to grade pumping loss, but that is very minuscule, and if you're driving it "like you stole it" it won't be visible to you at all anyway.
As for the OCI duration ... did you take any UOAs with the lighter grade PCMO? If you did, I'd say do the same thing with the HDEO and let the data speak to you. If you didn't take UOAs, then why worry about it now? It's not like you were following any OEM limits anyway. It's highly likely you were under-utilizing the PCMO; I don't see why the same would not apply to the HDEO. My point is that unless you have data for comparison, it's all just a guess. And so if you're going to guess, it's my estimate that there's no sane reason to think that the HDEO will suffer any indignity that the PCMO was able to avoid.