I have a 93 F150 pickup (5.0L) that gets maybe 1K miles per year. I use dino oil in it, but wonder why I can't let it go for more than a year for oil change? I know everyone says change every 6 mo or 1 year, but why? Does the oil go bad? I have read about condensation, but that gets burned off/boiled off when the engine is running right?...otherwise you would see that light colored crud under the oil cap. Just trying to find out what the real story is behind change it at least once a year. Is it just the oil company marketing?
Longer than 1 year OCI with low mileage?
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Kestas
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This question has come up a number of times with vintage car owners. You can leave it in longer than one year. One member did a UOA on two-year-old oil and it was fine.
mobil submitted a paper to the SAE in the 90s that showed the results of the 5yr long "aunt millie" tests, both low usage and short cycles. if mid '90s synthetic could handle that, i don't think any usage cycle you would be comfortable with would hurt it. i am about to send in a OA on my dad's tundra that had M1 10w30 in it for 5yrs, 10k miles. i expect it will be another boringly excellent tundra OA.
JHZR2
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Im of the opinion thatif you use a good syn and ensure that most/all uses are long-distance (so the oil gets to temperature), then the oil will be good for more than a year. Some of the newer OLMs have or had the ability to go 2 years - my saab for example can do that...
Ill have a UOA on my brother's 94 3000GT VR-4 that has gone about 2 years with only highway use and limited overall mileage, sometime around Christmas.
Ill have a UOA on my brother's 94 3000GT VR-4 that has gone about 2 years with only highway use and limited overall mileage, sometime around Christmas.
The only concern I would have, from reading these boards, is the condensation and fuel dilution.
Just be sure you get it up to tempature and drive it around for 30mins or so every month or two, go tool around on the highway and give it a little exercise. Try to make sure you have it up to temp before you put it away to make sure the condensation is (as best that can be) burned off.
Just be sure you get it up to tempature and drive it around for 30mins or so every month or two, go tool around on the highway and give it a little exercise. Try to make sure you have it up to temp before you put it away to make sure the condensation is (as best that can be) burned off.
I'm at 14 months (if I'm not mistaken) and 2500 miles on the M1 0w-40 in my BMW. I'm in no hurry to change it. I may do that over the christmas break, because I've got a stash of GC green that this BMW is jonesin' for.
I sleep well at night because I get it out on the highway once in a while for an hour or more to burn off any condensation there might be.
Look for the UOA in December or January if you want some data to back this up.
I sleep well at night because I get it out on the highway once in a while for an hour or more to burn off any condensation there might be.
Look for the UOA in December or January if you want some data to back this up.
Originally Posted By: SuperDave456
The only concern I would have, from reading these boards, is the condensation and fuel dilution.
Just be sure you get it up to tempature and drive it around for 30mins or so every month or two, go tool around on the highway and give it a little exercise. Try to make sure you have it up to temp before you put it away to make sure the condensation is (as best that can be) burned off.
+1
The only concern I would have, from reading these boards, is the condensation and fuel dilution.
Just be sure you get it up to tempature and drive it around for 30mins or so every month or two, go tool around on the highway and give it a little exercise. Try to make sure you have it up to temp before you put it away to make sure the condensation is (as best that can be) burned off.
+1
When you do drive the truck, get it good and hot, at least the last trip when going for extended storage.
The oil itself will not go bad from simply aging 1 year, otherwise many on this forum would have to discard their huge oil stashes.
If you have no known fuel or engine management issues, you can go longer than a year.
So a couple of years is an OK OCI for you.
The oil itself will not go bad from simply aging 1 year, otherwise many on this forum would have to discard their huge oil stashes.
If you have no known fuel or engine management issues, you can go longer than a year.
So a couple of years is an OK OCI for you.
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The information you want is in SAE Paper #981444, entitled: "Advanced Synthetic Passenger Vehicle Engine Oils for Extended Oil Drain Performance"
Presented by Mobil at the 1998 Fuels and Lubricants Meeting of the SAE
the infamous "aunt millie test", probably the most destructive oil test ever invented, don't try this at home kids, we are trained professionals....
1. The aunt minnie test is the test of "the severity on the engine oil during this type of testing is attributed to conditions where the engine rarely reaches optimum operating temperatures."
2. The driving test consists of two short cycles, a 3 mile and 1.5 mile test.
3. "Under this severe driving condition, synthetic oil can provide excellent protection against engine wear and deposit formation."
4. The bulk oil temp ranged from 90 C in the summer to 30 C in the winter.
5. Fuel dilution was as high as 11%.
6. Cleanliness was excellent, the deck sludge rating was 9.7 out of 10.
7. "The iron content showed a low rate of increase, only 100 ppm after 40 months, although there has been a steady increase to over 600 ppm over the last 22 months. The source of iron has not been determined, as visual inspection of the engine did not indicate any abnormal wear or corrosion. In addition, elevated iron levels have not appeared in other test vehicles operating under 'aunt minnie' conditions."
The oil was a 5W30 running in a 3.1 L V6 with no oil drains.
The oil volume sampled was 5.5L and make-up was 4.4L. TBN retention was 33.
Test duration was for 60 months.
if synthetic will last 5 YEARS under these conditions, i think any TIME interval is strictly for your memory, not for the oil. note that some manufacturers say that oil SHELF life is 5 years (what, you wanted consistency???). actually, the bottles may start coming apart after then.
Presented by Mobil at the 1998 Fuels and Lubricants Meeting of the SAE
the infamous "aunt millie test", probably the most destructive oil test ever invented, don't try this at home kids, we are trained professionals....
1. The aunt minnie test is the test of "the severity on the engine oil during this type of testing is attributed to conditions where the engine rarely reaches optimum operating temperatures."
2. The driving test consists of two short cycles, a 3 mile and 1.5 mile test.
3. "Under this severe driving condition, synthetic oil can provide excellent protection against engine wear and deposit formation."
4. The bulk oil temp ranged from 90 C in the summer to 30 C in the winter.
5. Fuel dilution was as high as 11%.
6. Cleanliness was excellent, the deck sludge rating was 9.7 out of 10.
7. "The iron content showed a low rate of increase, only 100 ppm after 40 months, although there has been a steady increase to over 600 ppm over the last 22 months. The source of iron has not been determined, as visual inspection of the engine did not indicate any abnormal wear or corrosion. In addition, elevated iron levels have not appeared in other test vehicles operating under 'aunt minnie' conditions."
The oil was a 5W30 running in a 3.1 L V6 with no oil drains.
The oil volume sampled was 5.5L and make-up was 4.4L. TBN retention was 33.
Test duration was for 60 months.
if synthetic will last 5 YEARS under these conditions, i think any TIME interval is strictly for your memory, not for the oil. note that some manufacturers say that oil SHELF life is 5 years (what, you wanted consistency???). actually, the bottles may start coming apart after then.
I think it depends on how your one year driving is done.
If you drive every day with less than 10 miles, change it out. If you drive every other week with a 200 miles trip on the highway, you are ok.
If you drive every day with less than 10 miles, change it out. If you drive every other week with a 200 miles trip on the highway, you are ok.
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Time will destroy the vehicle before anything else. You can take your pick. The oil probably won't contribute or control wear that is going to occur by just sitting idle. While the per mile stuff is tremendous ..the per year total probably isn't so bad compared to (some) other services.
How would "mid ninties" synthetics compare with 2009 synthetics. In the mid ninties all synthetics were PAO as opposed to now when most are Gr. III. Those PAO syns were usually touted as high mileage which isn't the case with the newer stuff.
Kestas
Staff member
I can understand how synthetic can outperform regular oil with regard to shear resistance, oxidation resistance, and heat resistance. But how does synthetic protect better than regular oil in the "aunt millie" test?... what is the mechanism? Is it because maintains its lubrication properties better with fuel and water dilution?
As many have already posted, it'll depend on getting the engine warm enough to burn off the junk in the crankcase & what type of oil you use.
I recently performed a UOA on a BMW track car I have, that rarely gets any use anymore. The oil has been in for 5-3/4 years now, and about 6.4k miles, with two races on it. The car rarely gets started, and when it does, about 75% of the time it doesn't get the oil hot (large sump & oil cooler for racing), as it's just being moved in/out of storage. Oil in there is Amsoil Series 2000 20w-50 (too bad they discontinued it). Bottom line, is that wear was extremely low, and TBN was stellar at 6.59 even after all this time with very short drives. At this rate, the oil may last to 8 or 9 years old...
Of course your fuel dilution, any coolant contamination, and fuel sulfur content variation will effect your results. YMMV.
I recently performed a UOA on a BMW track car I have, that rarely gets any use anymore. The oil has been in for 5-3/4 years now, and about 6.4k miles, with two races on it. The car rarely gets started, and when it does, about 75% of the time it doesn't get the oil hot (large sump & oil cooler for racing), as it's just being moved in/out of storage. Oil in there is Amsoil Series 2000 20w-50 (too bad they discontinued it). Bottom line, is that wear was extremely low, and TBN was stellar at 6.59 even after all this time with very short drives. At this rate, the oil may last to 8 or 9 years old...
Of course your fuel dilution, any coolant contamination, and fuel sulfur content variation will effect your results. YMMV.
Good point 4wheels. I'm not sure why I was going to do a UOA along with my oil change (typically how I do it). What I should do is UOA and leave it in the sump if it's OK.
Originally Posted By: Kestas
I can understand how synthetic can outperform regular oil with regard to shear resistance, oxidation resistance, and heat resistance. But how does synthetic protect better than regular oil in the "aunt millie" test?... what is the mechanism? Is it because maintains its lubrication properties better with fuel and water dilution?
bingo. as far as the mid 90s oils vs today, as with all things, it depends. for this sort of profile i would use 0w40 M1, or any other oil that meets MB229.5. this means it is not only an extended range oil, but also meets some pretty rough specs as far as wear and cleanliness goes. i would probably call time at 5 years, but i wouldn't worry about anything shorter...
I can understand how synthetic can outperform regular oil with regard to shear resistance, oxidation resistance, and heat resistance. But how does synthetic protect better than regular oil in the "aunt millie" test?... what is the mechanism? Is it because maintains its lubrication properties better with fuel and water dilution?
bingo. as far as the mid 90s oils vs today, as with all things, it depends. for this sort of profile i would use 0w40 M1, or any other oil that meets MB229.5. this means it is not only an extended range oil, but also meets some pretty rough specs as far as wear and cleanliness goes. i would probably call time at 5 years, but i wouldn't worry about anything shorter...
With the high quality of conventional oils these days, I would have no problem running 2 years 3-4k miles with the latest SM rated oils.
I don't see condensation being a problem when the vehicle is not driven frequently -- this is usually only a problem for a vehicle that gets tons of short trips and the oil never gets heated up adequately to evaporate it off. An infrequently used vehicle is not necessarily the same type of service conditions.
There was a 3 year UOA on Maxlife 5W-30.
And I ran conventional 5W-30 for a 2 year OCI (2800 miles) in my 1987 Jetta, and the oil still had good TBN. This is with lots of short trips and through 2 harsh Alberta winters.
I don't see condensation being a problem when the vehicle is not driven frequently -- this is usually only a problem for a vehicle that gets tons of short trips and the oil never gets heated up adequately to evaporate it off. An infrequently used vehicle is not necessarily the same type of service conditions.
There was a 3 year UOA on Maxlife 5W-30.
And I ran conventional 5W-30 for a 2 year OCI (2800 miles) in my 1987 Jetta, and the oil still had good TBN. This is with lots of short trips and through 2 harsh Alberta winters.
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