Changing oil less often is better for your engine - SAE

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From the other Mobil post where they tested AP I noticed this graph. It shows Fe in the 30ppm range and gradually dropping over the 20,000 mile interval. What you need built into an oil though to be comfortable going that far is good oxidation resistance, which not all oils have. That leads to deposits. I'm not sure why the image was rotated, but it does show that as time went oil the wear metals dropped significantly.



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Wear metals are always higher in the first OCI. Most of this comes from the bedding-in or 'sacrificial' wear that engine designers purposely allow for. An engine after a few thousand miles is a measurably more efficient lump of metal than it is in its brand new state, so some wear is a good thing.

Arguably the life of an engine oil becomes easier as time goes by. The antiwear system has less to do because there's less metal-on-metal asperity action & lower concentrations of wear metal in oil reduces the tendency of the oil to oxidise. In the longer term, you will very likely see blow-by increase as the rings wear & lose their tension. This isn't good for oil both from an oxidation point of view & because of higher levels of oil strip-out.
 
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Originally Posted by madeej11

You have to change your oil at 3750 because you probably own sorry to say, a piece of junk. What kind of foolishness is that to even buy a vehicle that needs an OCI of 3750 miles. Talk about starting off badly right from the get go. Also I think that's news to everyone here that 90% fall under severe service. Where did you come up with that figure? That's not even close. They may OCI as such but they certainly don't need to.



Amazing how so many are willing to show their ignorance on a forum.
 
Originally Posted by SonofJoe
Wear metals are always higher in the first OCI. Most of this comes from the bedding-in or 'sacrificial' wear that engine designers purposely allow for. An engine after a few thousand miles is a measurably more efficient lump of metal than it is in its brand new state, so some wear is a good thing.

Arguably the life of an engine oil becomes easier as time goes by. The antiwear system has less to do because there's less metal-on-metal asperity action & lower concentrations of wear metal in oil reduces the tendency of the oil to oxidise. In the longer term, you will very likely see blow-by increase as the rings wear & lose their tension. This isn't good for oil both from an oxidation point of view & because of higher levels of oil strip-out.


Great points as always.
cheers3.gif
 
Originally Posted by SonofJoe
Wear metals are always higher in the first OCI. Most of this comes from the bedding-in or 'sacrificial' wear that engine designers purposely allow for. An engine after a few thousand miles is a measurably more efficient lump of metal than it is in its brand new state, so some wear is a good thing.

Arguably the life of an engine oil becomes easier as time goes by. The antiwear system has less to do because there's less metal-on-metal asperity action & lower concentrations of wear metal in oil reduces the tendency of the oil to oxidise. In the longer term, you will very likely see blow-by increase as the rings wear & lose their tension. This isn't good for oil both from an oxidation point of view & because of higher levels of oil strip-out.


SonofJoe, do you prefer the 10w30 grade due to less VII's, and often lower volatility? Some have noticed a reduction in blow by and oil consumption with 10w30's, despite the market ruling them obslete at this point.
 
Originally Posted by madeej11

You have to change your oil at 3750 because you probably own sorry to say, a piece of junk. .


That's a silly statement.
 
Arguably the 'ideal' 10W30 doesn't yet exist.

Euro ACEA 10W30s are usually cursed by their need to meet 3.5 min HTHS. Not only does this mean they're extremely difficult to make (without great gobs of synthetic base stock) but it means they contain far more VII than they ideally should & this in turn incrementally pushes up Noack.

US ILSAC 10W30s only need to meet 2.9 cP min HTHS but are cursed by their need to pass Sequence VI Fuel Economy tests. As often as not, this means the oil's CCS is dropped way below the 7000 cP max spec (some times as low as 3800-ish). This again jacks up the VII content and pushes up the Noack quite markedly.

My ideal 10W30 would be an API only (ie non-ILSAC, non-ACEA) beast that met 2.9 min HTHS & didn't need to pass the Sequence VI. In my time I made quite a few all Group II 10W30 oils with a KV100 of 9.31 cst & a CCS-30 of 6,999 cP. They all contained the barest minimum of VII & had relatively low Noacks. Unsurprisingly they performed brilliantly on all sorts of rig & engines tests!!
 
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Originally Posted by SonofJoe
Arguably the 'ideal' 10W30 doesn't yet exist.

Euro ACEA 10W30s are usually cursed by their need to meet 3.5 min HTHS. Not only does this mean they're extremely difficult to make (without great gobs of synthetic base stock) but it means they contain far more VII than they ideally should & this in turn incrementally pushes up Noack.

US ILSAC 10W30s only need to meet 2.9 cP min HTHS but are cursed by their need to pass Sequence VI Fuel Economy tests. As often as not, this means the oil's CCS is dropped way below the 7000 cP max spec (some times as low as 3800-ish). This again jacks up the VII content and pushes up the Noack quite markedly.

My ideal 10W30 would be an API only (ie non-ILSAC, non-ACEA) beast that met 2.9 min HTHS & didn't need to pass the Sequence VI. In my time I made quite a few all Group II 10W30 oils with a KV100 of 9.31 cst & a CCS-30 of 6,999 cP. They all contained the barest minimum of VII & had relatively low Noacks. Unsurprisingly they performed brilliantly on all sorts of rig & engines tests!!

Interesting info,thank you. What do you think of Delo 10w30? It's not "resource conserving" as far as I can tell.
 
Originally Posted by SonofJoe
I'm going to go out on a limb here and say that however hard you look, you won't find a single professional oil formulator out there that genuinely believes engine oil has anything to do with TGDI timing chain wear. Timing chain wear problems are a function of chain design, manufacture & metallurgy.

Yes, timing chain wear is now a specified engine test that has to be passed by oil formulators to get spec approvals but has this actually changed the way oils are formulated? I could be wrong but I'd bet serious money that it hasn't.


Are these timing chain wear tests done on the OEM's specific chain design, or is the wear test done on some very specific standard chain and sprocket design and test setup so the true anti-wear effect of just the oil formulation can be detected? If chain and sprocket design and metallurgy was all over the place it could mask the oil's anti-wear performance.
 
Originally Posted by dogememe
Originally Posted by SonofJoe
Arguably the 'ideal' 10W30 doesn't yet exist.

Euro ACEA 10W30s are usually cursed by their need to meet 3.5 min HTHS. Not only does this mean they're extremely difficult to make (without great gobs of synthetic base stock) but it means they contain far more VII than they ideally should & this in turn incrementally pushes up Noack.

US ILSAC 10W30s only need to meet 2.9 cP min HTHS but are cursed by their need to pass Sequence VI Fuel Economy tests. As often as not, this means the oil's CCS is dropped way below the 7000 cP max spec (some times as low as 3800-ish). This again jacks up the VII content and pushes up the Noack quite markedly.

My ideal 10W30 would be an API only (ie non-ILSAC, non-ACEA) beast that met 2.9 min HTHS & didn't need to pass the Sequence VI. In my time I made quite a few all Group II 10W30 oils with a KV100 of 9.31 cst & a CCS-30 of 6,999 cP. They all contained the barest minimum of VII & had relatively low Noacks. Unsurprisingly they performed brilliantly on all sorts of rig & engines tests!!

Interesting info,thank you. What do you think of Delo 10w30? It's not "resource conserving" as far as I can tell.


Hmmmm...tricky...

On the plus side it's got a decently high CCS.

On the minus side it's an HDDO, not a PCMO, which means this stuff probably contains a shed load of ashless dispersant which will seriously ramp up the Noack of the oil.

I did try and find a Noack number for Delo 10W30 but all I could find was a generic 'less than 13%'. Such coyness on Chevron's part says to me this stuff has a high Noack; 12%-ish maybe? In which case I might say avoid.

PS - if anyone has more info I'm happy to change my mind...
 
Originally Posted by SonofJoe
Arguably the 'ideal' 10W30 doesn't yet exist.
Euro ACEA 10W30s are usually cursed by their need to meet 3.5 min HTHS. ...
US ILSAC 10W30s only need to meet 2.9 cP min HTHS but are cursed by their need to pass Sequence VI Fuel Economy tests. ...
Does the "ideal" 5W-20 exist, at least for engines specified for xW-20? Seems they would not suffer those particular "curses," therefore might not require as much VII? I recall you'd prefer 10W-20, which unfortunately remains purely hypothetical hereabouts.

Thanks, SoJ, for the interesting and informative series of posts in this thread!
 
Originally Posted by SonofJoe
Originally Posted by dogememe
Originally Posted by SonofJoe
Arguably the 'ideal' 10W30 doesn't yet exist.

Euro ACEA 10W30s are usually cursed by their need to meet 3.5 min HTHS. Not only does this mean they're extremely difficult to make (without great gobs of synthetic base stock) but it means they contain far more VII than they ideally should & this in turn incrementally pushes up Noack.

US ILSAC 10W30s only need to meet 2.9 cP min HTHS but are cursed by their need to pass Sequence VI Fuel Economy tests. As often as not, this means the oil's CCS is dropped way below the 7000 cP max spec (some times as low as 3800-ish). This again jacks up the VII content and pushes up the Noack quite markedly.

My ideal 10W30 would be an API only (ie non-ILSAC, non-ACEA) beast that met 2.9 min HTHS & didn't need to pass the Sequence VI. In my time I made quite a few all Group II 10W30 oils with a KV100 of 9.31 cst & a CCS-30 of 6,999 cP. They all contained the barest minimum of VII & had relatively low Noacks. Unsurprisingly they performed brilliantly on all sorts of rig & engines tests!!

Interesting info,thank you. What do you think of Delo 10w30? It's not "resource conserving" as far as I can tell.


Hmmmm...tricky...

On the plus side it's got a decently high CCS.

On the minus side it's an HDDO, not a PCMO, which means this stuff probably contains a shed load of ashless dispersant which will seriously ramp up the Noack of the oil.

I did try and find a Noack number for Delo 10W30 but all I could find was a generic 'less than 13%'. Such coyness on Chevron's part says to me this stuff has a high Noack; 12%-ish maybe? In which case I might say avoid.

PS - if anyone has more info I'm happy to change my mind...

Hmm, now you're making me reconsider using it LOL. I mean it's already in my truck but I could use a different oil next time...
 
Great, great posts here soj...

Here's a interesting observation I made months and months ago guys....

Warren Oil had a 10w30 with a NOACK of like 7.9%

CCS of 4600

Havoline 10w30 had a NOACK was like soj said of 12%

CCS of 5600+

I'm going to check the CCS of the Warren Oil...

Well.. too low of a CCS for the Warren Oil. Can't always be a winner
lol.gif
 
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Originally Posted by dogememe
Hmm, now you're making me reconsider using it LOL. I mean it's already in my truck but I could use a different oil next time...


You should be fine to use it. Your engine will still run efficiently.
 
Brigadier, is that the best you can do. Ignorance is displayed in many ways, like buying that vehicle and ignoring to do your research. You never replied to that 90% thing either. That is ignorance.
 
Originally Posted by ZeeOSix
Originally Posted by SonofJoe
I'm going to go out on a limb here and say that however hard you look, you won't find a single professional oil formulator out there that genuinely believes engine oil has anything to do with TGDI timing chain wear. Timing chain wear problems are a function of chain design, manufacture & metallurgy.

Yes, timing chain wear is now a specified engine test that has to be passed by oil formulators to get spec approvals but has this actually changed the way oils are formulated? I could be wrong but I'd bet serious money that it hasn't.


Are these timing chain wear tests done on the OEM's specific chain design, or is the wear test done on some very specific standard chain and sprocket design and test setup so the true anti-wear effect of just the oil formulation can be detected? If chain and sprocket design and metallurgy was all over the place it could mask the oil's anti-wear performance.



I'm out of the loop as regards these exact tests. However if they follow the usual pattern of test development, it will work something like this...

The test will be primarily developed by the OEM using an engine (not a rig) using all standard OEM parts. The engines (which will essentially be brand new for each test) will be part dismantled, precisely measured (particularly all aspects of the timing chain) & rebuilt. An exact test protocol will be developed using a standardised fuel. Each test will have a short run in period followed by a lengthy, any usually very severe, run on a fresh candidate oil. After completion of the test, the oil will be drained & analysed. The engine will be stripped down & measured in great detail. Any wear or stretch in the chain will be measured to the nearest micron. This will then be judged next to a prescribed set of 'acceptable' limits & the test judged to be a pass or fail.

As this test is specifically focused on timing chain wear, it would be normal for the OEM to produce & store a specific batch of timing chains (plus associated gubbins) dedicated for testing.

This sounds both complex & expensive and it is!

Now here's the thing. The OEM can't say something like 'absolutely no wear or stretch us permitted' (even though ideally that's what they want). If they did, no oils would ever be deemed 'acceptable'. So the test limits will allow for an 'acceptable' level of wear & stretch. This definition of 'acceptable' is usually arrived at by a process of negotiation by all parties (ie Oil companies, AddCos, test houses, industry bodies, etc) and NOT just set by the OEM.

This often leads to a 'generous interpretation' of what is acceptable & a test that most up-to-date oils can pass (or get very close to passing). The test serves to exclude the very bad rather than force the formulation of something exceptionally good.

Also remember these tests are usually one simulated OCI pass or fail tests. With these tests, you almost never consecutively repeat the procedure 20 times to simulate what happens over the full lifetime of the vehicle.

Hope that helps...
 
Originally Posted by bbhero
Great, great posts here soj...

Here's a interesting observation I made months and months ago guys....

Warren Oil had a 10w30 with a NOACK of like 7.9%

CCS of 4600

Havoline 10w30 had a NOACK was like soj said of 12%

CCS of 5600+

I'm going to check the CCS of the Warren Oil...

Well.. too low of a CCS for the Warren Oil. Can't always be a winner
lol.gif






You've raised a very important point.

If you're making a 10W30 using the same slate of base oils (say Chevron Group II) & the same DI/VII, then a drop in CCS from 5,600 to 4,300 will ALWAYS increase the Noack of the oil.

However if you make the Havoline oil from all Group II & the Warren oil from a 70:30 blend of Group II: Group III, you can very easily find that the Warren oil has a much lower Noack despite having a lower CCS.

Likewise, if you made both oils from all Group II but you made the Havoline oil with OCP VII & the Warren oil from HSD VII, you would see the same thing.

How can the average bloke in the street tell? Sadly you can't & the oil companies will never let on.
 
Here's the thing with this study that bothers me. That "aged oil" that supposedly shows lower engine wear, is also going to have contamination in it, especially direct injected applications that are dumping more fuel into it. So why would we want to leave our oil in longer when that's going on? Also, you can't possibly get every last drop of old oil out when you change it, there could be 10-15% of your total capacity left behind no matter how long you leave the drain plug off. I know with my Corvette, the manual says the capacity is 7 quarts, but when I refill it, the dipstick shows full with only 6 quarts added. So a lot is being left behind (I have seen pics of the oil pan and I believe a good half quart gets stuck in there alone) So my thought is that if the old oil helps "reactivate" the new oil, we don't really need to do anything different than we're already doing, as you'll always have that little bit of old oil doing it's job.
 
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