I'm not an oil engineer so I don't mix...
Oil compatibility myths
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Many years ago I knew a lady that worked for Shell oil and her only thing was that if you have used a straight weight oil and then went to a multi weight you would have a motor that used oil from that time on. Made sense to me since the parts had worn clearances for the thicker oil and the thin would pass on through.
The only time I would mix oils is to use up odd quarts of leftover oil....and then I try to use oils with similar additive packages. For instance, if I had a quart or two of Royal Purple leftover I would mix it with Valvoline Synpower which has (or had before dexosG2) a similar additive package (ie: higher sodium and no moly).
My reasoning is that if I mixed it 50/50 with say, Havoline...I'd have half the moly of Havoline and half the sodium of RP...which may or may not be as good as either oil individually. Of course I would add any brand to my crankcase if I was low and that's all that was available (because oil brands are compatible even if mixing isn't optimal).
PS: As I mentioned, dexos G2 has changed some formulations so I'd have to do new research before mixing....
My reasoning is that if I mixed it 50/50 with say, Havoline...I'd have half the moly of Havoline and half the sodium of RP...which may or may not be as good as either oil individually. Of course I would add any brand to my crankcase if I was low and that's all that was available (because oil brands are compatible even if mixing isn't optimal).
PS: As I mentioned, dexos G2 has changed some formulations so I'd have to do new research before mixing....
Originally Posted By: VQLT
The oldest is that you need to use the same brand or bad things will happen.. the engine gets 'used' to a brand.
How did a myth like this get started? was is a marketing campaign to make sure you did not buy a competitors oil or is there a factual basis for the myth
Back in the day 10W30 meant 10weight. 100K miles in the 60s and 70s meant your engine was worn out. You changed your oil every 3000 miles too. My father did most of his oil changes himself. 4 cans of oil and a trusty sharp can opener or a metal punch with a spout if he could find it. If he went to a garage to get his oil changed they asked what brand he used.
So in fact i think marketing wasnt like it is now. The local garages seemed to have 4 or 5 brands..unlike today.
The oldest is that you need to use the same brand or bad things will happen.. the engine gets 'used' to a brand.
How did a myth like this get started? was is a marketing campaign to make sure you did not buy a competitors oil or is there a factual basis for the myth
Back in the day 10W30 meant 10weight. 100K miles in the 60s and 70s meant your engine was worn out. You changed your oil every 3000 miles too. My father did most of his oil changes himself. 4 cans of oil and a trusty sharp can opener or a metal punch with a spout if he could find it. If he went to a garage to get his oil changed they asked what brand he used.
So in fact i think marketing wasnt like it is now. The local garages seemed to have 4 or 5 brands..unlike today.
I once mixed 3 quarts of 10w-30 Valvoline with 2 quarts of 10w-40 Castrol GTX in a SBC, and after only 4 months that engine blew up on me because as it turns out, there was no oil in the sump. And then on top of that, my grandmother died the very next year!
So I don't ever mix my oils after that.
So I don't ever mix my oils after that.
My $0.04 worth ...
1.) Back in the day I worked a lube room at Flying A station in a fairly rich part of the country. We did a lot of service work, like $40K month. The boss had a drum that we had to drain all the oil cans into at the end of the change. He'd use that oil in the company pick-up and on poor folks cars when the widow could not afford to change the oil, or something... We all dipped into the old drum to keep our cars and trucks full. Nary a problem anywhere
2.) What do you do on vacation when the sump is a qt low, and you are 500 miles from anywhere? Panic because the station you stopped at does not have your oil brand? No, you top up and keep going. You know that oils No 2 job is cooling and heat transfer and a full sump is better than a 1/2 empty one.
So mixing works and always has. Is it as good as a one brand/one viscosity run - prolly not. So, if you're concerned, clip 1,000 miles off your OCI and cruise on.
Me, I figure it's new clean oil so I extend the interval figuring I just did a partial change on the road
1.) Back in the day I worked a lube room at Flying A station in a fairly rich part of the country. We did a lot of service work, like $40K month. The boss had a drum that we had to drain all the oil cans into at the end of the change. He'd use that oil in the company pick-up and on poor folks cars when the widow could not afford to change the oil, or something... We all dipped into the old drum to keep our cars and trucks full. Nary a problem anywhere
2.) What do you do on vacation when the sump is a qt low, and you are 500 miles from anywhere? Panic because the station you stopped at does not have your oil brand? No, you top up and keep going. You know that oils No 2 job is cooling and heat transfer and a full sump is better than a 1/2 empty one.
So mixing works and always has. Is it as good as a one brand/one viscosity run - prolly not. So, if you're concerned, clip 1,000 miles off your OCI and cruise on.
Me, I figure it's new clean oil so I extend the interval figuring I just did a partial change on the road
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My riding mower always gets an oil mix.
Its engine contains 1.5L of oil. When doing an oil change, only 1L comes out and I only have to put in 1L to fill it up. So there's still 0.5L (33%) of the previous oil in it.
I contacted the manufacturer about this (Toro) and they answered that I don't need to drain the remaining oil which would involve tilting the engine. For this engine, 1L of new oil is enough for a proper oil change according to them.
Its engine contains 1.5L of oil. When doing an oil change, only 1L comes out and I only have to put in 1L to fill it up. So there's still 0.5L (33%) of the previous oil in it.
I contacted the manufacturer about this (Toro) and they answered that I don't need to drain the remaining oil which would involve tilting the engine. For this engine, 1L of new oil is enough for a proper oil change according to them.
I was firmly in the “no mixing” crowd until I started using this forum. The more I read, the more I realized most modern oils you buy are mixed anyway, especially synthetic blend. I tried It with the mother-in-law’s beater with a leaky valve cover. I used whatever loose quarts I had until I replaced the gasket. No problems.
Then I tried it in the family van. I had lots of AAP and AZ clearance oil. I put in 4 quarts of 0W-20, a quart of 20W-50, and a quart of 5W-30, all synthetic. I did the math, and it was right in the 5W-30 range. It’s at 3K and hasn’t lost a bit. Mileage is great, and it runs quiet.
Then I tried it in the family van. I had lots of AAP and AZ clearance oil. I put in 4 quarts of 0W-20, a quart of 20W-50, and a quart of 5W-30, all synthetic. I did the math, and it was right in the 5W-30 range. It’s at 3K and hasn’t lost a bit. Mileage is great, and it runs quiet.
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Originally Posted By: Crispysea
I was firmly in the “no mixing” crowd until I started using this forum. The more I read, the more I realized most modern oils you buy are mixed anyway, especially synthetic blend.
What ???
Oils are "blended" from a variety of ingredients, with design intent to pass multiple suites of tests required by the API and various OEMs.
NONE are mixed...where did you come to that understanding ?
Mixing is taking fully formulated oils as I described and combining them, either through need, or some ASSumption as to an intent.
They are NOT the same...and NO oil manufacturer takes jugs of 0W20 and 20W50 and calculated that it will be a 5W30.
BTW, how did you go about calculating the 5W part of your mix...it would be a useful technique to understand.
I was firmly in the “no mixing” crowd until I started using this forum. The more I read, the more I realized most modern oils you buy are mixed anyway, especially synthetic blend.
What ???
Oils are "blended" from a variety of ingredients, with design intent to pass multiple suites of tests required by the API and various OEMs.
NONE are mixed...where did you come to that understanding ?
Mixing is taking fully formulated oils as I described and combining them, either through need, or some ASSumption as to an intent.
They are NOT the same...and NO oil manufacturer takes jugs of 0W20 and 20W50 and calculated that it will be a 5W30.
BTW, how did you go about calculating the 5W part of your mix...it would be a useful technique to understand.
The engineers that design an oil have used (and rejected) specific base oils & additives to achieve a desired result. When we mix something else in, the result is unknown and may not be as good as the original. That's not to say it will harm your engine. If you are worried, don't use it for an extended oil change. One could always mix in advance, send a sample out for a voa, then decide based on the analysis results.
Originally Posted By: Shannow
Originally Posted By: Crispysea
I was firmly in the “no mixing” crowd until I started using this forum. The more I read, the more I realized most modern oils you buy are mixed anyway, especially synthetic blend.
What ???
Oils are "blended" from a variety of ingredients, with design intent to pass multiple suites of tests required by the API and various OEMs.
NONE are mixed...where did you come to that understanding ?
Mixing is taking fully formulated oils as I described and combining them, either through need, or some ASSumption as to an intent.
They are NOT the same...and NO oil manufacturer takes jugs of 0W20 and 20W50 and calculated that it will be a 5W30.
BTW, how did you go about calculating the 5W part of your mix...it would be a useful technique to understand.
Exactly, what the composition of the base stock happens to be that is used by the manufacturer to produce a formulated motor oil is not the question. Nothing is "blended" after the fact. ExxonMobil does not take formulated conventional Mobil oil and add some formulated M1 oil to make a blend.
Originally Posted By: Crispysea
I was firmly in the “no mixing” crowd until I started using this forum. The more I read, the more I realized most modern oils you buy are mixed anyway, especially synthetic blend.
What ???
Oils are "blended" from a variety of ingredients, with design intent to pass multiple suites of tests required by the API and various OEMs.
NONE are mixed...where did you come to that understanding ?
Mixing is taking fully formulated oils as I described and combining them, either through need, or some ASSumption as to an intent.
They are NOT the same...and NO oil manufacturer takes jugs of 0W20 and 20W50 and calculated that it will be a 5W30.
BTW, how did you go about calculating the 5W part of your mix...it would be a useful technique to understand.
Exactly, what the composition of the base stock happens to be that is used by the manufacturer to produce a formulated motor oil is not the question. Nothing is "blended" after the fact. ExxonMobil does not take formulated conventional Mobil oil and add some formulated M1 oil to make a blend.
I could see the myth about never being able to run conventional again after a change with synthetic being developed as a marketing tool...tell the customer to try some fancy synthetic, then mention afterwards that they can't go back to cheaper stuff and hope they return to your shop for the more expensive changes in the future.
They kind of did it backwards with me at Midas some years ago, though...I decided to try a synth or semi-synth change in my RAV6 just for the heck of it and then got the warning before I signed the paperwork about never being able to use conventional again. I was scared for a second, then realized that the very existence of semi-synth meant that synth and dino types could be mixed.
They kind of did it backwards with me at Midas some years ago, though...I decided to try a synth or semi-synth change in my RAV6 just for the heck of it and then got the warning before I signed the paperwork about never being able to use conventional again. I was scared for a second, then realized that the very existence of semi-synth meant that synth and dino types could be mixed.
OVERKILL
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Originally Posted By: krismoriah72
Back in the day 10W30 meant 10weight.
The W has always meant "Winter". Remember, there were single-weight Winter-rated oils available like 20W, 15W, 10W...etc.
Back in the day 10W30 meant 10weight.
The W has always meant "Winter". Remember, there were single-weight Winter-rated oils available like 20W, 15W, 10W...etc.
Additive clash! 'Clash' is a concept consumers can digest.
Out of the 3 major additive pack producers out there, the ZDDP from Lubrizol for example, will battle it out mercilessly with the ZDDP from Infineum in the name of each clan's honor, and the result will be clumped up and blood laced oil. Do you want the blood of the innocent in your engine oil? OF course not!
Do not mix. Bad things will happen
Out of the 3 major additive pack producers out there, the ZDDP from Lubrizol for example, will battle it out mercilessly with the ZDDP from Infineum in the name of each clan's honor, and the result will be clumped up and blood laced oil. Do you want the blood of the innocent in your engine oil? OF course not!
Do not mix. Bad things will happen
Originally Posted By: PeterPolyol
Additive clash! 'Clash' is a concept consumers can digest.
Out of the 3 major additive pack producers out there, the ZDDP from Lubrizol for example, will battle it out mercilessly with the ZDDP from Infineum in the name of each clan's honor, and the result will be clumped up and blood laced oil. Do you want the blood of the innocent in your engine oil? OF course not!
Do not mix. Bad things will happen
Mix oils and your engine might look like Paul Simonon hit it with his bass!
Additive clash! 'Clash' is a concept consumers can digest.
Out of the 3 major additive pack producers out there, the ZDDP from Lubrizol for example, will battle it out mercilessly with the ZDDP from Infineum in the name of each clan's honor, and the result will be clumped up and blood laced oil. Do you want the blood of the innocent in your engine oil? OF course not!
Do not mix. Bad things will happen
Mix oils and your engine might look like Paul Simonon hit it with his bass!
4WD
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Originally Posted By: OVERKILL
Originally Posted By: krismoriah72
Back in the day 10W30 meant 10weight.
The W has always meant "Winter". Remember, there were single-weight Winter-rated oils available like 20W, 15W, 10W...etc.
Originally Posted By: krismoriah72
Back in the day 10W30 meant 10weight.
The W has always meant "Winter". Remember, there were single-weight Winter-rated oils available like 20W, 15W, 10W...etc.
The Esso advertisement is correct, when cold it meet the requirements for a 10W but isn't labeling it a "10 weight" oil.
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