Reducing OCIs with Age

[camrydriver111]

I've heard a few people recommend reducing OCIs with engine age. For example: run full OCIs up to 100k miles, reduce OCI to 75% up to 150 miles, run 50% OCI after that. This is most relevant with European OCIs of 10k miles or more. The logic is as the engine wears it will contaminate the oil quicker, and you need to change it sooner.

I was wondering if any BITOGers follow this practice, or have any experience with it?

 

[Lyman]

My Jeep is now over 150,000 miles and the oil is still clean as can be at 5,000 miles OCIs. I see no reason to shorten the OCI unless you are having problems.

 

[Shannow]

I wouldn't see the point really.

As they age, they are worth less to you both in monetary (retained OR resale value) and emotional terms.

Keep on trucking at the manufacturer's OCI IMO.

 

[demarpaint]

I did just the opposite with a few beaters over the years. As they aged and fell out of the lime light for whatever reason, I stretched the OCI a bit more, especially if the vehicle leaked or used some oil. No point in spending more money on an old ride I was losing interest in.

 

[01rangerxl]

Might be a good idea on vehicles with longer manufacturer suggested OCIs, but I find myself doing the opposite. I've been slacking off more. I wrote 182K miles for the next change on my 2002 Ranger's sticker...right now it's about 1000 miles over that, but I do plan to change it this weekend. Whoops. Granted, my OCI was pretty arbitrary anyway.

 

[CT8]

It gets to a point of return for the money spent.

 

[Ihatetochangeoil]

I've been doing UOA for several years, and my current ride with 70K has no substantial differences in either wear metals nor contaminates than my old ride which was the same engine in a different model year with 200+K on it.

I see no logic in doing what you have stated; but all my experience is with American iron and API oils. I DID see my oil pressure drop with engine age, but it remained within factory specs.

 

[BigCahuna]

It will always be cheaper to change your oil VS changing the motor or the car itself.No matter how old your car gets,,,

 

[hpb]

I stretch the intervals further and further as they get older.

 

[Ram01]

Stretch the OCI as it gets older just top off as needed.

 

[Nick1994]

Originally Posted By: hpb
I stretch the intervals further and further as they get older.
That's what I was about to say.

My car is sitting at only 210k miles. It's still a spring chicken!

I'm considering stretching out the oil even further.

 

[HTSS_TR]

Originally Posted By: demarpaint
I did just the opposite with a few beaters over the years. As they aged and fell out of the lime light for whatever reason, I stretched the OCI a bit more, especially if the vehicle leaked or used some oil. No point in spending more money on an old ride I was losing interest in.

I did exactly the same with my former LS400.

I first do 7.500 miles with name brand Dino and mid priced filter, after about 120-150k miles changed to synthetic and do 15-20k miles or 1 year with cheap filter.

The E430 is 16 years old with 18x,xxx miles, but I keep doing 1 year OCI of around 10-12k miles.

 

[RooflessVW]

The VW is 12 years old and has 140k and I still do 10k/1yr oil and filter intervals.

The BMW is 10 years old and has 125k and I do 15k/1year oil and filter intervals.

I don't normally hit the miles, but I would have no issues if I did.

 

[slacktide_bitog]

On a related note, do you think OLM's calculate shorter OCI's as they rack up the miles? No owner'a manual suggests shorter drains with high miles, either.

 

[marc1]

Originally Posted By: demarpaint
I did just the opposite with a few beaters over the years. As they aged and fell out of the lime light for whatever reason, I stretched the OCI a bit more, especially if the vehicle leaked or used some oil. No point in spending more money on an old ride I was losing interest in.


Couldn't agree more. As my vehicles age the OCI goes up. My powertrains always far outlast other parts of the vehicle.

 

[vitez]

Interesting theory, and it might hold some validity if the engine was getting very worn. Basing presumed engine wear on miles driven alone though is really just a WAG.

Me? The Mrs.'s 2005 Chrysler Pacifica with the 3.5 V6 is at 289K km (180K miles) using an annual OCI with AMSOIL Signature Series 0w30 and an EAO42 filter. No plans on messing with success.

 

[SirTanon]

My Fusion is over 213,000 miles, and I've run the same 7,500 mile OCI in it since I first got it.

My used oil analysis have been excellent, so I plan on making my next OCI a 10,000 mile OCI. Then again, the engine is pretty darn clean.

Rather than adjusting your OCI length on how many miles are on the car/engine, maybe you should consider basing them on how clean the engine is, and how good your used oil analysis have been coming back.

 

[WobblyElvis]

Over the past few years I extended the OCI on my car from 7,500 miles to 14,000 and analyzed the oil a few times along the way. Over the years the car gradually burnt more oil and lately, at 170,000 miles, it burns a quart every 4,500 miles. I thought that with fresh oil constantly entering the pan I could extend the OCI.
The used oil analysis came back fine but I ran the filter 19,800 miles and it came out black and loaded with carbon. I think the oil consumption/blow by contaminates the oil. So even if you are constantly adding oil, you still have to change it just as often.

 

[Kuato]

Originally Posted By: Ihatetochangeoil
I've been doing used oil analysis for several years, and my current ride with 70K has no substantial differences in either wear metals nor contaminates than my old ride which was the same engine in a different model year with 200+K on it.

I see no logic in doing what you have stated; but all my experience is with American iron and API oils. I DID see my oil pressure drop with engine age, but it remained within factory specs.



^This. Only a used oil analysis can answer that question, everything else is speculation.

 

[Joe90_guy]

I would say there's an argument for moving to a heavier, less volatile engine oil as your car ages.

As your bores and ring faces wear with age, the engine will need a thicker hydrodynamic film for the metal surfaces to ride on. The easiest way to do this is moving to a higher viscosity oil.

Also as the bores & rings wear, the engine will produce more blow-by which will directionally both dump more fuel into the oil and strip more of the light front-end out of the oil to be routed through the intake to be burnt. Moving to a thicker, but less volatile oil mitigates against this. A progression from 5W20 to 10W30 to 15W40 to 20W50 might make sense.



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