2012 Buick Regal GS | Pennzoil Plat 5w-30 | 3,800mi, 13 months (Time-based OCI)

[Oneill5491]

I'm on a mission to find the longest time-based OCI I can safely get away with on synthetic oil. I feel that the 12-month maximum that a lot of people advocate for on this board is too conservative especially for a light-duty passenger vehicle.

My Regal is a daily driver but accumulates miles slowly since my daily commute is just a few miles. I captured a sample of my oil without changing it so I'm still running on this oil and plan to do another UOA at around the 18-month mark.

It's unfortunate that the NAPA/WIX analysis doesn't include an actual number for fuel dilution since I'm running a DI engine, but the diagnosis summary states it was okay.

Vehicle: 2012 Buick Regal GS
Engine: EcoTec LHU DI 2.0T I4
Oil: Pennzoil Platinum Full Synthetic 5w-30
Miles on Oil: 3,800
Time on Oil: 13 Months
Miles on Engine: 48,100

 

[CleverUserName]

The base number is 2.6. That oil is done. Change it now.

 

[madeej11]

Iron is obviously high for that mileage. Looks like viscosity is in the 20weight range possibly due to Gdi, turbo and short trip fuel dilution. My opinion would be to change it out. Other members may feel differently. jmo. Good luck. (At 2.6) I'm not really worried about tbn just yet.

 

[PPWarrior]

You need to change it sooner and use a better quality oil-- Mobil or Castrol.

 

[4WD]

Originally Posted by CleverUserName
The base number is 2.6. That oil is done. Change it now.


Think it surely would be between now and 18 months ...

 

[Oneill5491]

Hey thanks for your input guys.

Originally Posted by CleverUserName
The base number is 2.6. That oil is done. Change it now.

At a base value of 2.6, I'm not too worried about that yet as I understand oil is still usable with TBN > 1.

Originally Posted by madeej11
Looks like viscosity is in the 20weight range possibly due to Gdi, turbo and short trip fuel dilution. My opinion would be to change it out.

That's an interesting point. Didn't know much about Viscosity values until I looked it up just now. The analyst said it was within "operating range", so I wonder what they establish as acceptable limits for 30 weight oil.

Sounds like I'll be changing it out before 18 months.

 

[Malo83]

Originally Posted by PPWarrior
You need to change it sooner and use a better quality oil-- Mobil or Castrol.

He's using the best oil available, agree on the oil changes.

 

[CleverUserName]

Originally Posted by Oneill5491
Hey thanks for your input guys.

Originally Posted by CleverUserName
The base number is 2.6. That oil is done. Change it now.

At a base value of 2.6, I'm not too worried about that yet as I understand oil is still usable with TBN > 1.

Originally Posted by madeej11
Looks like viscosity is in the 20weight range possibly due to Gdi, turbo and short trip fuel dilution. My opinion would be to change it out.

That's an interesting point. Didn't know much about Viscosity values until I looked it up just now. The analyst said it was within "operating range", so I wonder what they establish as acceptable limits for 30 weight oil.

Sounds like I'll be changing it out before 18 months.


You don't have TAN so the condemnation limit is in question, however I'm sure its > 50% TBN depletion so it's time to be changed.

Originally Posted by Malo83
Originally Posted by PPWarrior
You need to change it sooner and use a better quality oil-- Mobil or Castrol.

He's using the best oil available, agree on the oil changes.


That's not the best oil available. It's walmart oil, LOL.

 

[madeej11]

Walmart oil is just as adequate as the others. This thread is getting stupid. Out.

 

[4WD]

Originally Posted by madeej11
Walmart oil is just as adequate as the others. This thread is getting stupid. Out.


Yep - There is hardly an oil sold at Walmart that could not do his OCI ...
But if it takes 13 months to get to just 3800 miles ?
The slightly elevated iron is probably a small clue it goes through many of the warm up cycles where a bit of extra wear takes place ... Not worth paying for another UOA either ... Spend that at Walmart on oil ...

 

[Linctex]

There's probably no need for synthetic oil in this low-miles-per year application.

But honestly, $6 price difference over 1 whole year is only 50 cents a month.

I would keep doing what you are doing, and just change it once a year.
18 months will NOT kill this engine, either. 6 of one, half dozen.....