OCI miles or time?

[Picky1]

I have a 2012 Subaru Legacy Premium 2.5 (my third Subaru) which I purchased new in March 2012. I had the factory fill changed out after 3,000 miles, and have another oil change at 7,500 (first two oil changes were free). During the oil change at 7,500 miles I switched to Subaru synthetic 5w30 since the manual specified 7,500 OCIs I felt more comfortable running synthetic.

I do not drive a lot since I work from home, the car now has 12,500 miles and per the manual the oil should be changed every 7,500 mile or 7.5 months. It has now been 7+ months since the 7,500 oil change, I check the oil all of the time and haven’t used a drop and the oil still looks like new.

Do I get the oil changed now, or hold off until I hit 15,000 mile service interval? Will holding off jeopardize my warranty?

 

[HTSS_TR]

For warranty purpose you need to change it at 7.5 months even if you have less than 3-4k miles with synthetic oil. After warranty period you can easily do 1 year/7.5k miles with any syn oil if your driving condition is not severe.

 

[simple_gifts]

I'd suggest going by the book under warranty; why load the gun?

 

[901Memphis]

Time won't hurt the oil but the double check maximum warranty length in time. I wouldn't even flinch about running two years on a synthetic if the mileage was in check.

 

[jimbrewer]

There is a reason why the manual is written that way.

Time won't hurt the oil, but a pattern of short trips and periods of inactivity sure will. Relatively low mileage won't make it alright. It makes it worse, since the additives which attack the acids never get fully heated long enough to do their job as well as they should.

When you think about it, the requirement for a calendar based change regardless of mileage is another way of saying this is super severe service. All that Synthetic, high-tech goodness does you no good sitting in the sump at ambient temperature.

I'm OK with someone running synthetic, especially if he isn't paying much of a premium for it. It sounds like you are, though. I think someone like you is a good candidate to use the regular oil as per the manual.

Or, you could do a used oil analysis at 7.5 months, and continue on if you like it. I figure its cheaper and easier to follow the manual with the regular stuff.

 

[toneydoc]

Do what you need to do to keep the warranty in effect. And use whatever oil you like. Dino or synthetic. 5-6k miles on a quality synthetic every 6 months is fine. You will not miss a few bucks and will have peace of mind.

 

[Merkava_4]

I go OLM 50% or 6 months. Whichever comes first.

 

[901Memphis]

I've seen oil analysis at 3 years with pretty normal TAN , i am sure Dnewton has some stowed away somewhere. People freak about time but its not a big deal. The oil isn't getting any more acidic sitting in the sump.

 

[ChrisD46]

Even after warranty I'm staying with 6 months / 6,500 miles on PP synthertic ... I'm re-thinking what is severe service and what is not . Even if vehicle gets up to temp for 25 minutes + for 3 ~ 4 days a week , I've been fooling myself into thinking I'm not severe service . The way I see it - if I can't get through hearing the long version of : "Ina - Gadda - Da - Vida" on the interstate without applying the brakes heavily ...Then it's severe service

 

[jimbrewer]

"The way I see it - if I can't get through hearing the long version of : "Ina - Gadda - Da - Vida" on the interstate without applying the brakes heavily ...Then it's severe service"

There's an SAE paper on that I think.

 

[sw99]

There needs to be a balance. If you drive a lot, than miles. If it sits a lot, then time. If both, find the happy medium...

 

[demarpaint]

Still under a warranty and you come up on the time limit in the owners manual and you're short on the miles, then you go by time. Come up on the miles stated in the owners manual and you're short on the time, you go by miles.

 

[gfh77665]

Highway cruising is the easiest on oil. Biggest factor is number of cold starts/short runs. Time is all but irrelevant.

 

[901Memphis]

25 minutes after the oil is up to temperature? That is not severe service by any definition.

Take a look at this thread for some actual data plot points for time and temperature of oil and coolant.

http://www.bobistheoilguy.com/forums/ubb...nt=2&page=2