Does the time between oil changes matter?

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Sep 7, 2014
I drove my truck mostly on the weekends. I will do about 7K in a year and a half. Does the time between oil changes matter as much as milage? If it is not it seems as though it was a good way for the auto service industry to keep cars coming in. Thoughts.
If it's just about the money,
once a year is a good compromise that won't break your budget considering all your other ownership costs.

But if you want to know for the truth, then you'll need to get an oil analysis to check your specific usage with your specific oil. many people here extend to 2,3 more years for low use vehicles.
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I don't think there's any conspiracy by the automakers to keep cars coming in as you say however for the general public who tend to be less than current with auto maintenance I do think that for them it's a good idea to bring in a vehicle if they cannot service them themselves.
For us bitogers who know better we know that oil cannot tell time,however the oil certainly can accumulate moisture and fuel if primarily short tripped,or if the PVC isn't working properly and those engines will require a shorter oci.
For guys like me who run mostly highway miles a name brand synthetic should easily run 10000 miles.
So let's start by finding out what you drive,where you drive at,what oil whether syn or mineral and is the engine well maintained.
I get my vehicles up to operating temp and maintain it for at least 40 minutes every time I drive them,with very few exceptions.
That type of service evaporates any accumulated fuel and water which keeps the oil in serviceable condition for longer than a short tripper.
Keep that in mind.
And no,time in sump is irrelevant. Oil cannot tell time. There are a pile of used oil analysis with low miles and in service for years and the used oil analysis indicated the oil was still serviceable.
The whole "peace of mind" nonsense and "cheap insurance" is laughable. Changing the oil before it's reached it's condemnation point isn't cheap at all. Consider what it takes to get it. Especially considering the whole exercise isn't going to extend engine life whatsoever.
And peace of mind is hillarious. Is someone truly implying their minds won't give them peace if their oil isn't changed.
I dont believe in time being a factor. I really think the time basis of an oil change is just quick lube myths. Ive had the same Pennzoil Ultra in my honda for over two years and its still holding up great. Under the valve cover looks fantastic.
Time becomes a factor if your oil is heavily contaminated through short trips. The elevated contamination depletes additives faster.

You'll see reports here of people with intelligent oil life monitors that reduce significantly with short trips.

I have UOA on Pennzoil Ultra Euro 5w40 that at 5,200 miles and 15 months will not be able to reach the 10,000 mile interval that Mercedes set. There's a reason they set a time limit as well.
It doesn't in your instance. If you drove the kids to the school bus stop 10x a week it would, but you warm it up.
Miles matter more than time IMO. I haven't changed the oil in my Olds Aurora since April, 2010. It doesn't get driven much, it sits in the garage and it's fine. When I start driving it more, I'll change it. Keeping the oil topped off is the most important thing. 5-10,000 miles of nothing but short trips with cold weather mixed in - it's probably time.
As long as the oil filter doesn't rust out I wouldn't worry about it. I have a Duramax that is going on 3 years without a change due to being used only two or three times a year. Every oil sample comes back as fine.
Originally Posted By: Clevy
And peace of mind is hillarious. Is someone truly implying their minds won't give them peace if their oil isn't changed.

Well yeah.....

I even view my time here on BITOG as "counseling".
In your mild California climate even short trips
won't build up condensation in the oil (fuel dilution perhaps) but from the sound of things if you're getting the oil up to temperature every time you start the engine then time is not a factor and you can changes the oil and filter based solely on mileage..

7,000 miles on a conventional oil is probably about time to change your oil.
Originally Posted By: Clevy
Is someone truly implying their minds won't give them peace if their oil isn't changed.

Oh yeah... I've seen many members here implying exactly that. Can't get a good night's sleep thinking there's "dirty" oil sitting in their engine.

To those people, I usually say just go ahead and do it. Changing an oil is cheaper than paying for a shrink or treating ulcers.
yea, just not just thinking either.

You can tell people go on the internet and probably spend quite a few minutes reading or searching for posts on the subject.
Then when, they post not necessarily looking for a neutral answer but people to just validate what they are feeling in their gut.

All this is wasted time and energy in mental deliberation, instead just making a decision one way or another and having your thoughts and energy move onto other things.
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When I was talking to Mobil (back when they had techs in Oz to talk to), about M1, they offered that annual oil changes were their recommendation for vehicles out of warranty...40,000km, or 5,000km, either way, 12 months. 12-18, I wouldn't get my knickers bunched.

If you are playing dino, and by the looks of it doing 4,500-5,000 miles a year, a year sounds perfect...Doesn't have to be the first Sunday after the full moon that follows the equinox precise.
Been debating a bit of that myself....since I have 15-16 months on my QSUD with a delco (hengst) filter.

Oil is nearly clean, as the fill has maybe 2k on it.

I kinda don't care, with as much as I've learned here....It's not driven much, but I do warm it up to move the oil, and I try to drive it a distance once in a while to clear things out.

My thought is unless it gets trapped in the garage (like it did last year) due to the nasty winter, I think I'm going to let it roll to 2 years...
It takes 18 months for my truck to reach 7500 miles and 24 months for my car to reach ~8500 miles. The truck is used all year round, more so in the "colder" temps and the car is basically a "warm" weather/vacation vehicle. Both have super clean valve trains when looking through the oil fill. I've bought both of these vehicle new. Up until now the truck used Motorcraft 5W-20, it now has Havoline 5W-20 synthetic and the car has always used various 5W-30 synthetic oils. At oil change time the oils on both always come out dark golden. I know that is not a judgement of the oil but the fact that the valve train is darn near spotless says something for the OCI's and the oil.

It is my belief that if you have a car that isn't driven everyday but is always fully warmed up when you do drive it, that you don't need to change the oil every year. I will have around 5k on the oil in my Corvette by the time I reach the one year mark, and my oil life monitor is still around 70% at this point so I feel it's a waste of good oil to drain it just because one year has passed. To me the mileage is more important and M1 can go a lot longer than 5k.
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