How often do you change your oil??
August 11th, 2013, 07:34 PM
#1
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Location: Richardson, Texas
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How often do you change your oil??
I have a '75 Delta with a stock 455 and only drive it between 500 and 1000 miles a year.
Oil & filter change once a year ample?
What are you guys doing with your cars that don't get driven that often?
Thanks in advance!
Oil & filter change once a year ample?
What are you guys doing with your cars that don't get driven that often?
Thanks in advance!
August 11th, 2013, 07:46 PM
#2
Justin
Join Date: Mar 2012
Location: utah
Posts: 3,447
I change mine twice a year before storage and before I drive it for the summer
Edit : I start it every month and let it get warm as well thought I would add this info in
Edit : I start it every month and let it get warm as well thought I would add this info in
Last edited by oldstata; August 11th, 2013 at 07:59 PM.
August 11th, 2013, 07:55 PM
#3
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Once a year is more than sufficient for that tractor motor, and that many miles.
With a highly-tuned race motor, I wouldn't argue with twice a year, but not a stock lump, especially a low-compression mid-'70s one.
- Eric
With a highly-tuned race motor, I wouldn't argue with twice a year, but not a stock lump, especially a low-compression mid-'70s one.
- Eric
August 12th, 2013, 04:42 AM
#10
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My daily drivers get Napa (Valvoline) full synthetic and a Napa Gold/Wix filter every 5k. My Oldsmobiles get Amsoil full synthetic (Z-Rod 10w-30 for the '68 and Dominator Racing 15w-40 in the '65) and a Napa Gold/Wix filter once a year in the spring. They usually see less than 2500 miles a piece per year. The '65 also gets about 100 passes at the track. I was changing the oil in the '65 every 50 passes but I sent a sample in to Amsoil and they analyzed it. They told me I could easily double my change interval.
August 12th, 2013, 05:43 AM
#12
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Every 3000 miles or 6 months. If the engine is started, it should be fully warmed up before shutting it off, which usually means driving it a few miles. Just starting it and running a few minutes in the garage and shutting it off can result in acid forming in the oil. Fully warming it up burns off the moisture that causes the acid to form, not to mention it also warms up and circulates the transmission fluid/oil and the rear end oil. Articles I have read say it is better to NOT start it than to start and not fully warm it up.
August 13th, 2013, 11:23 AM
#15
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
uhhh, you have to change oil???? 
Based on mileage and storage time. Oil will break down in the crank case even if it's not being used all that often, especially in short drive situations.
Based on mileage and storage time. Oil will break down in the crank case even if it's not being used all that often, especially in short drive situations.
August 16th, 2013, 03:29 PM
#16
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First, for brown7373, what acid is actually forming in the oil? I thought oil and water were immiscible (meaning they don't dissolve in one another), and that the oil just floats on the water because of their density difference. I've always heard that the danger, as you do say, is in starting the engine but not letting it warm up. Moisture does accumulate in the crankcase because of condensation on cylinder walls and so forth, and this water is normally boiled off when the engine is next run and reaches operating temperature. If the engine is not allowed to reach operating temperature, the water is circulated in the engine but not boiled off, and it can corrode metal parts. But I've never heard that the water actually forms an acid.
Second, Allan, I've never heard that oil has a shelf life. It actually can be recycled indefinitely, and that's what happens to oil collected by repair shops when they do oil changes. We change oil every so often not because anything has happened to the oil directly but because of the accumulation of impurities that can degrade its effectiveness. Filter out these impurities, which is what the oil filter does up to a point, and the oil is fine. But as far as I've ever heard and read, nothing happens to oil that just sits at room temperature.
August 16th, 2013, 04:39 PM
#18
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Is the oil still in the original bottles or cans it came in, or is it in the engine that was pulled out?
If the former, there would be no problem in using it, at least in an engine of that era that was designed to use it.
If the latter, of course not, as whatever impurities were in the oil when it was last driven are still there, and of course you want to drain that oil and put in fresh. But don't throw the old oil away. Take it to a place the recycles used oil so that it can be reused.
If the former, there would be no problem in using it, at least in an engine of that era that was designed to use it.
If the latter, of course not, as whatever impurities were in the oil when it was last driven are still there, and of course you want to drain that oil and put in fresh. But don't throw the old oil away. Take it to a place the recycles used oil so that it can be reused.
August 17th, 2013, 03:49 AM
#21
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My Jetfire will be changed every year because it will be driven enough. With the oil going through the turbo I figure it is likely getting hot while traveling through it. My Rallye 350 gets changed anywhere from 3 years to 5 years. It is lucky to get 200 miles a year with this year only getting 18 miles. I use mobil 1 and changed it 2 years ago. It looks like I just poured it in.
August 17th, 2013, 05:06 AM
#22
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Location: Iowa
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I guess I'm old school but never thought too much with oil coming out as clean as it went in. Oil is supposed to take the contaminants out so not to create excessive wear on engine parts.
So I repeat.........oil is cheaper than a motor.
August 17th, 2013, 05:13 AM
#23
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Why give it to the dump, or some chain store for free, when a local guy can use it and save himself a few bucks?
- Eric
August 17th, 2013, 05:26 AM
#25
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When I was a kid, every year the road crews used to re-do the road by our summer place - put down crushed stone, grade it, roll it, and oil it.
- Eric
August 17th, 2013, 05:28 AM
#26
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I agree but I only have 231 miles on it in 2 years. At this rate, It will be another 2 or 3 years before i change it again.
August 17th, 2013, 06:04 AM
#27
August 17th, 2013, 06:31 AM
#28
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I am not a chehemical engineer jauny75, but I have read numerous articles in various car magazines over the past 50 years about the potential dangers of not waming up the engine and oil sufficiently to burn off (evaporate the moisture) from the oil. Maybe the articles I have read are not accurate, but I have read many. I googled the subject and here is the first link I found. If you read aout 3/4 of the way down under Oxidation Inhibitors and Corrosion Inhibitors, it talks abut how acid can form.
http://motoroilbible.com/motor-oil-b...st-chapter.php
http://motoroilbible.com/motor-oil-b...st-chapter.php
August 17th, 2013, 06:48 AM
#29
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Here is the referenced passage from the linked document (just to save you-all a lot of hunting):
So, the question becomes, if using an oil with an adequate quantity of base additives to buffer the acidic combustion byproducts, does it matter if it sits in the engine for a while, or not?
In other words, the buffers should eliminate acids that have formed, so the oil should be relatively neutral, so there should be no harm in leaving it for a while.
Or is there more to it than that?
- Eric
Oxidation Inhibitors
As you probably can guess, oxidation inhibitors are additives that manage to reduce the tendency of an oil to oxidize (chemically react with oxygen). They are also called antioxidants. There are two types:
One type of antioxidant destroys free radicals. In fact, you may have heard of antioxidants which can be found in vitamin supplements. In human beings, free radicals can cause cell damage and even cancer. Antioxidants neutralize these free radicals in the body to reduce the chance of them causing any damage. In motor oil they serve a similar function by destroying free radicals that aid in the process of oxidation.
The other type of antioxidant reacts with the peroxides in the oil. These peroxides are involved in the process of oxidation. Reaction with the antioxidant removes them from the oxidation process, thereby lessening the chance of motor oil oxidation.
Oxidation inhibitors also serve one more very important purpose. They protect against bearing corrosion. You see, bearing corrosion is caused by acids within your motor oil. These acids come from combustion by-products, but they can also be the result of oxidation. So, by inhibiting motor oil oxidation, antioxidants also protect against bearing corrosion.
Corrosion Inhibitors
Although antioxidants prevent the acids caused by oxidation, they do nothing to neutralize the acids caused by combustion by-products. Therefore, other additives must be used in order to keep these acids in check and to protect engine components from their effects.
Some corrosion inhibitors are designed to protect non-ferrous metals by coating them so they cannot come in contact with acids within the oil. Other corrosion inhibitors are designed to actually neutralize the acids within the oil. The acid neutralizing capability of an oil is expressed by its Total Base Number (TBN).
Since diesel engines tend to have more acid build up within the oil, these oils generally have TBN between 9 and 14. Gasoline oil TBN levels are normally lower at 5 to 8. Generally, higher quality oils and/or those that are designed for longer drain intervals will have higher TBN numbers.
Synthetics will almost always fall at the high end of the scale for both gas and diesel oils, while petroleum oils will typically fall at the low end of the scale because they are changed frequently anyway. There is normally no need for petroleum oils to have high TBN values.
As you probably can guess, oxidation inhibitors are additives that manage to reduce the tendency of an oil to oxidize (chemically react with oxygen). They are also called antioxidants. There are two types:
One type of antioxidant destroys free radicals. In fact, you may have heard of antioxidants which can be found in vitamin supplements. In human beings, free radicals can cause cell damage and even cancer. Antioxidants neutralize these free radicals in the body to reduce the chance of them causing any damage. In motor oil they serve a similar function by destroying free radicals that aid in the process of oxidation.
The other type of antioxidant reacts with the peroxides in the oil. These peroxides are involved in the process of oxidation. Reaction with the antioxidant removes them from the oxidation process, thereby lessening the chance of motor oil oxidation.
Oxidation inhibitors also serve one more very important purpose. They protect against bearing corrosion. You see, bearing corrosion is caused by acids within your motor oil. These acids come from combustion by-products, but they can also be the result of oxidation. So, by inhibiting motor oil oxidation, antioxidants also protect against bearing corrosion.
Corrosion Inhibitors
Although antioxidants prevent the acids caused by oxidation, they do nothing to neutralize the acids caused by combustion by-products. Therefore, other additives must be used in order to keep these acids in check and to protect engine components from their effects.
Some corrosion inhibitors are designed to protect non-ferrous metals by coating them so they cannot come in contact with acids within the oil. Other corrosion inhibitors are designed to actually neutralize the acids within the oil. The acid neutralizing capability of an oil is expressed by its Total Base Number (TBN).
Since diesel engines tend to have more acid build up within the oil, these oils generally have TBN between 9 and 14. Gasoline oil TBN levels are normally lower at 5 to 8. Generally, higher quality oils and/or those that are designed for longer drain intervals will have higher TBN numbers.
Synthetics will almost always fall at the high end of the scale for both gas and diesel oils, while petroleum oils will typically fall at the low end of the scale because they are changed frequently anyway. There is normally no need for petroleum oils to have high TBN values.
In other words, the buffers should eliminate acids that have formed, so the oil should be relatively neutral, so there should be no harm in leaving it for a while.
Or is there more to it than that?
- Eric
August 17th, 2013, 06:55 AM
#30
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My understanding is fully warming up the engine and oil burns off the moisture that causes the acid and corrosion. Here is a link to Quaker State Oil that also talks about acid formation. I admit that Quaker State knows more about the subject than I do.
http://www.quakerstate.com/#/used-oi...rotection-test
http://www.quakerstate.com/#/used-oi...rotection-test
August 17th, 2013, 07:02 AM
#31
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And here is that quote:
The acid can be present in the oil, but needs a polar solvent, such as water, to dissociate into its constituent ions, which are the reactive components.
If the water is boiled off, the acids remaining in the oil should be relatively inactive.
- Eric
The purpose of this test, also known as the Ball Rust Test, is to determine how well an oil protects against rust formation after the engine is shut off. The need for this kind of protection might not seem obvious until you consider that water and acid are both byproducts of the combustion process. A certain amount of that water and acid ends up in your oil. So it’s important that some of your oil continues to coat critical engine parts, forming a protective rust barrier, even after your car has been shut down for the night and most of the oil has drained to the crankcase. Otherwise that water and acid could begin to rust your engine from the inside. In the Ball Rust Test a steel metal ball is submerged in the test oil. Acid is added to the oil. After 18 hours the ball is removed and inspected for signs of rust and discoloration.
If the water is boiled off, the acids remaining in the oil should be relatively inactive.
- Eric
August 17th, 2013, 07:58 AM
#32
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Location: southeastern Michigan
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I am not a chehemical engineer jauny75, but I have read numerous articles in various car magazines over the past 50 years about the potential dangers of not waming up the engine and oil sufficiently to burn off (evaporate the moisture) from the oil. Maybe the articles I have read are not accurate, but I have read many. I googled the subject and here is the first link I found. If you read aout 3/4 of the way down under Oxidation Inhibitors and Corrosion Inhibitors, it talks abut how acid can form.
http://motoroilbible.com/motor-oil-b...st-chapter.php
http://motoroilbible.com/motor-oil-b...st-chapter.php
What I was curious about was the acid formation you were talking about. The author of this article talks about acids forming from "combustion by-products." This is different from the oil itself turning into an acid. The acids he's talking about are impurities just like any of the other impurities that get into the oil during use, and the inhibitors he's talking about are added to the oil to mitigate the effects of these combustion by-products. The accumulation of these and other impurities over time as the engine is run is why we periodically change the oil.
To get back to the basic point, yes, the engine should be fully warmed up whenever it's started so that accumulated moisture can be boiled off. But, no, oil is not going to spontaneously turn into an acid if it just sits there in a cold engine.
August 17th, 2013, 08:45 AM
#33
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
I guess my original comment about oil breaking down was a poor choice of wording. What I should have said was it loses some of it's 'effectiveness' over time whilst left in the crank case? My car hasn't run for 2 years and the oil was last changed in 2008. During that span it has made (2) 300 mile trips and several cruise trips around town. Enough to warm the engine fully. However when I redid the power steering the engine admittedly didn't get warmed up while I was bleeding the air from the pump and gearbox.
In our northern climate most of the engine wear/damage is caused by starting in very cold temps when oil viscosity can be an issue. That's why I've changed over to synthetic, and have a block heater since my car spends it's entire life outside.
I change oil myself (mostly because it's easy and waaaay cheaper than using a shop). The old oil gets stored till I have about 5 gallons, then I take it to a local tire shop that uses old engine oil for winter heating. It could also go to an ECO station to be recycled, but the tire shop is way closer and occasionally they do work for me (alignment), and I remind them I drop off used oil so it works out nicely.
In our northern climate most of the engine wear/damage is caused by starting in very cold temps when oil viscosity can be an issue. That's why I've changed over to synthetic, and have a block heater since my car spends it's entire life outside.
I change oil myself (mostly because it's easy and waaaay cheaper than using a shop). The old oil gets stored till I have about 5 gallons, then I take it to a local tire shop that uses old engine oil for winter heating. It could also go to an ECO station to be recycled, but the tire shop is way closer and occasionally they do work for me (alignment), and I remind them I drop off used oil so it works out nicely.
August 17th, 2013, 09:35 AM
#34
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Every 3000 miles or 6 months. If the engine is started, it should be fully
warmed up before shutting it off, which usually means driving it a few miles.
Just starting it and running a few minutes in the garage and shutting it off can
result in acid forming in the oil. Fully warming it up burns off the moisture
that causes the acid to form, not to mention it also warms up and circulates the
transmission fluid/oil and the rear end oil. Articles I have read say it is
better to NOT start it than to start and not fully warm it up.
warmed up before shutting it off, which usually means driving it a few miles.
Just starting it and running a few minutes in the garage and shutting it off can
result in acid forming in the oil. Fully warming it up burns off the moisture
that causes the acid to form, not to mention it also warms up and circulates the
transmission fluid/oil and the rear end oil. Articles I have read say it is
better to NOT start it than to start and not fully warm it up.
I said acid would form in the oil, I never said the oil would turn into acid.
August 17th, 2013, 10:08 AM
#35
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The acid forms in the oil as a result of combustion, and gets into the oil by blowing past the rings.
If the engine doesn't run, it doesn't form any acids. If it does run, it does.
The acids are relatively inert in the absence of water, but in the presence of water, the acids dissociate at a measurable rate into H+ and a conjugate. The H+ is highly reactive, especially in the presence of water, which facilitates electrochemical reactions, and can cause corrosion in places where you don't want it.
So, by reducing or eliminating the amount of water present in the crankcase and oil, you can minimize the amount of acidity, and therefore the amount of damage.
Since water exists in the air, and will condense inside of closed spaces with temperature changes over time, running the engine from time to time to heat it up and evaporate the water is reasonable.
However, since water is a product of combustion, running the engine will add some water to the crankcase (as well as adding more acids), and, more importantly, will add a lot of water to the exhaust system, which will cause premature rusting, so unless you heat up the exhaust system enough to evaporate all of the water there, as well, you are probably doing more damage by running the engine than by letting it sit with a miniscule amount of water and acids in the crankcase.
- Eric
If the engine doesn't run, it doesn't form any acids. If it does run, it does.
The acids are relatively inert in the absence of water, but in the presence of water, the acids dissociate at a measurable rate into H+ and a conjugate. The H+ is highly reactive, especially in the presence of water, which facilitates electrochemical reactions, and can cause corrosion in places where you don't want it.
So, by reducing or eliminating the amount of water present in the crankcase and oil, you can minimize the amount of acidity, and therefore the amount of damage.
Since water exists in the air, and will condense inside of closed spaces with temperature changes over time, running the engine from time to time to heat it up and evaporate the water is reasonable.
However, since water is a product of combustion, running the engine will add some water to the crankcase (as well as adding more acids), and, more importantly, will add a lot of water to the exhaust system, which will cause premature rusting, so unless you heat up the exhaust system enough to evaporate all of the water there, as well, you are probably doing more damage by running the engine than by letting it sit with a miniscule amount of water and acids in the crankcase.
- Eric
August 17th, 2013, 03:39 PM
#36
Administrator
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The additives and friction modifiers break down. The oil gets contaminated over time, sludge forms, inside of engine gets ugly. Then if you change your oil at extreme extended intervals then the detergent loosens the sludge and distributes it around the engine and destroys bearings.
August 17th, 2013, 05:15 PM
#37
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Location: Near Muskegon Michigan
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I just run Royal Purple and yes with a zinc additive anyways, and change it once a year as I only run around 1,000 miles or less. This year looks about to be around 600 give or take. I figure that running synthetic that I am fine. Even with the added cost, that's only 1 time per year. Napa gold always.
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