I drive 1000 miles/yr. Why change the oil yearly?

[fishugly]

In this last decade, I've only been putting around 1,000 miles per year on this van. I know it's recommended to change the oil yearly but it's tough for me when I pull the dipstick and the oil still looks relatively fresh. I'm guessing I'm going to be told that the oil starts breaking down upon use and that's the reason it should be changed. But still... I would like to be convinced, one way or the other.

I also see that some lesser know names (STP for example) are selling full synthetic oil for the same price as regular oil from the fancier names. If someone asked me to assume, I'd assume that these lesser known synthetics would perform better than a bigger name regular oil. But, that's only my assumption. I would like to be convinced one way or another.

FWIW, my 1995 5 cylinder has ~115,000 easy miles on her. She runs great and seems to burn little if any oil.

[Glenn]

Oil is cheap, much cheaper than repairing engine wear.

Oil has contaminates and acids from use. Over time this will cause damage.
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Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"

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#BlueSquare

[Abscate]

You can shut down all the meaningless debate by getting an oil analysis done by Blackstone and measuring the TBN number to see how much acid capacity is consumed by sitting.

Get the car up to temperature once every two weeks (30 minute run) and my guess is your oil will be fine for 2-3 years, but the data trumps the usual stupid oil debate.

FYI - I run two cars in this mode and find the above to be true for my situation. I typically change the oil every other year and use the oil as top off for a daily driver high mileage car that uses one quart every 2000-2500 miles.
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[RichBenn]

Cold, sitting oil “supposedly”, at least open oil, goes bad. Do not buy oil and let it sit for years. That’s possibly why car mfg require changing oil every 12 months, regardless of mileage. May also be some engine effect, like the moisture in the air getting to it and spoiling it.

My Chevy Volt (plug in hybrid) turns on the gas engine to if you go a month or so on electric. That may be more preventing gas varnishing than oil, although I’ve seen sticky lifters and oil bathed tensioners after a car has sat for years.(as well as many other problems).

Can’t say whether better oils are better regarding this “go bad” aspect or not. There are so many additives and synthetics today that I wouldn’t be surprised.

Perhaps someone has done oil analyses on sitting oil - sounds like a little research into why would be good.
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Rich

[fishugly]

Thank you all for your replies.

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[RichBenn]

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[Bulli Klinik]

I would be more concerned with the lack of oil on the bearing surfaces due to starting it infrequently than I would the oil going bad from sitting.

I'd consider using an oil additive like Lucas to prevent dry starts. At least it will keep some oil on the bearings. Better yet, go out and start it once in awhile.
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Mike K
Bulli Klinik
Colorado Springs

[Abscate]

Car in question is run every week to two weeks.

Bearing wear on startup is an internet mythology of epic proportion.

Start, don’t race, few seconds to pump up, then drive in cold engine mode just like the user manual says.

Important thing for this OP is to get the car hot enough to get water out. Penn State study says that 20 minutes of driving , 30 minutes in winter
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[jjvincent]

It’s funny how nobody ever brings up the transmission in these debates. Yet I’ve never seen a post where someone has a worn out motor due to the points mentioned. Yet we just could care less about the transmission. Manuals wear out the bearings and automatics wear out the valve bodies. Both are really expensive to fix yet we fixate on the engine.

[volkybus]

you know I THINK CHANGING THE oIL EVERY YEAR IS JUST OVERATED... i ALwase do it but on my air cooled lawn mower I change every other year and they last me at least 15 years... as far as the transmission on a VW I think about every 5 years should be enoulf..now on my high millage toyota the engine oil was changed every 3,000 miles or every year and the oil pressure relief froze open and blew all the seals...fresh good oil every time too.....that car is seasonal too so it unused for long streshes of time....good luck

[Abscate]

Your lawn mower gets about 25 hours of use a year and also is low stress and power. You could probably use Crisco in it and get long life

The big danger is getting water out of a low use engine which accumulated by the normal hot cold condense cycle from air in non-desert climates.

I recovered a 99 Volvo with a seized engine that sat from May to Jan, and the sump was full of chocolate milk from condensate. One oil change and it was all set.
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