Synthetic For Engine Cleaning

Joined
Feb 6, 2010
Messages
734
Location
KY, USA
I'm running approximately 15 year old conventional Citgo Supergard 10w40 in my '16 Versa. It just hit 30K miles and I did a transmission fluid drain/fill/filters. It will be due for an OC in about 1K miles and was wondering if since I have a few jugs of 15 year old 10w30 Pennzoil Platinum in the garage whether the members of the forum thought it would be beneficial to run synthetic oil for one OCI to help clean the engine then go back to the conventional or would you just continue to run the conventional? I know synthetic is supposed to be better oil but I've got probably around 8-10 cases of conventional that needs to be used up so I can't afford to just let it sit and switch to synthetic full time. I've ran conventional 10w40 for 45 years without any issues. Will the synthetic actually do any more cleaning than the conventional? I don't know much about oil technology thus the reason for the question.
 
Joined
Nov 9, 2008
Messages
18,648
Location
NH
Does that 15 years old oil meet required spec on your car?

Seems to me like if you used an in-spec oil and changed on a reasonable OCI, that you would have no reason to fear crud buildup in only 30k. Not on a modern EFI setup. I wouldn’t think of worrying about this.
 
Joined
Nov 20, 2006
Messages
26,836
Location
MA, Mittelfranken.de
No. Engine oil is not a cleaning solvent.
Provides exceptional cleaning power for dirty engines.

I can attest to the cleaning power of Mobil 1 oils seen during a tear down.
 
Joined
Aug 7, 2020
Messages
859
Not saying I agree or disagree, but, from the Mobil1 container ...

M1.jpg
 
Joined
Jan 18, 2020
Messages
1,757
Location
United States
mobil 1 new life 0w40 (now FS) was the oil XOM used to demonstrate sludge cleanup. this can be attributed to esterex additive. other mobil 1 oils like EP may perform similarly.
 

Attachments

  • 1152527D-E8FA-4BA5-9118-1A61A8D9C520.jpeg
    1152527D-E8FA-4BA5-9118-1A61A8D9C520.jpeg
    104.1 KB · Views: 131
Joined
May 30, 2010
Messages
13,845
Location
North Carolina

I can attest to the cleaning power of Mobil 1 oils seen during a tear down.
That, and mobil used to specifically state that the mobil 1 high mileage was intended to clean. I don't know if they still state that.


EDIT; Looks like they still state it.

 
Last edited:
Joined
Feb 9, 2017
Messages
699
Location
Vancouver, Canada
Personally, I'd not recommend flush either as there are risks of sludge chunks plugging some passages.
Oil meant for diesel engines and suitable for gas engines is what I'd use for a couple of shorter OCIs.
 
Joined
Sep 8, 2005
Messages
15,229
Location
Canada
15-year old oil is from about 2005, which means it should be SM-spec. So it is a ‘modern’ conventional oil that will have good quality group-II base oils and a strong add-pack.
At reasonable intervals, it should keep an engine perfectly clean without issue.
 
Joined
Dec 7, 2008
Messages
3,778
Location
Virginia

I can attest to the cleaning power of Mobil 1 oils seen during a tear down.
With one OCI? You agree that Mobil 1 will clean a 'dirty' engine by using it once?
 
Top