Change in brand brings increase in consumption?Why

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We've had many posts in which members have claimed a sometimes drastic increase in oil consumption when changing brands. PP appears especially prominent in these claims.
I don't think I've ever seen this myself, but there are too many members claiming to have seen this for it to be dismissed as myth or mere anecdote.
I wonder why a change in brand of oil might cause any change in oil consumption?
What technical explanation might there be for this?
Higher volatility?
This would bring only a small increase.
Switching from an oil at the thicker end of the grade to one at the thinner end?
Again, not that much of a difference.
What might cause a very noticeable increase in oil consumption when doing no more than changing brands within the same grade?
Is this real? I think it is based upon the number of longtime members who say they've seen it.
The question is how we can explain this in rational terms.
 
I think Mola or some of the other guys have chimed in on this before. Large changes in oil composition and additives can cause some "consumption" as the additives neutralize each other and interact. It's that chemistry stuff, above my head. I saw this when I switched my Forester from RT6 to Mobil1 0W40.

Therefore, I choose to stick all to Pennzoil synthetics. I've exclusively used PUP in my Fusion for the past 100k, and it still does not use any oil whatsoever, even over the last 17.2k OCI. It did thicken up just a hair, but with no top-off that's likely to be expected a little. I may drop back to 15k and not even bother checking UOAs anymore.
 
I haven't seen any drastic changes in oil consumption on my cars or trucks, but don't switch oils much. My Hayabusa would use way more Mobil 1 full synthetic motorcycle oil than Valvoline or any other conventional motorcycle oil - same weight used, 10W-40. I'd think high volatility certainly does play a role. One reason I look for oils that have a low NOACK.
 
I believe that increased oil consumption when changing brands is caused by a new mini-break-in. This can be caused by small difference in viscosity and different levels of different additives. I believe this because the oil consumption usually goes back to it original value after an oil change or two with the new oil. One reason I don't switch brands unless there is a good compelling reason. Ed
 
Originally Posted By: Eddie
I believe that increased oil consumption when changing brands is caused by a new mini-break-in.


It's caused by the existing "Tribo-Chemical Barrier" being UTTERLY DESTROYED
by the new formulation, and as the new TCB is formed in its place instead!

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Originally Posted By: Eddie
I believe that increased oil consumption when changing brands is caused by a new mini-break-in. This can be caused by small difference in viscosity and different levels of different additives. I believe this because the oil consumption usually goes back to it original value after an oil change or two with the new oil. One reason I don't switch brands unless there is a good compelling reason. Ed


And what would be this magical oil usage mechanism?
 
Originally Posted By: Linctex
Originally Posted By: Eddie
I believe that increased oil consumption when changing brands is caused by a new mini-break-in.


It's caused by the existing "Tribo-Chemical Barrier" being UTTERLY DESTROYED
by the new formulation, and as the new TCB is formed in its place instead!

grin.gif
crackmeup2.gif
lol.gif
grin2.gif



But seriously though, this would make some sense for increased wear. It makes no apparent sense for increased consumption.

(Unless the tribolayer seals leaks, which I don't think it will, much.)

Apart from volatility and viscosity difference, to explain that you'd have to go for something like a negative interaction between the VII's reducing the effective viscosity.

I dunno if there's any experimental evidence for that and if there is I bet it'll be hard to find.
 
I've changed brand of oil in all my cars. Never had a issue!! The cars that use oil i had to add oil. The car that never had to add oil not a drop. Every 10k or 5k My feeling each oil has something to offer in the way of cleaning. Just my input
 
I consumed a bit when going from 0w20 Castrol Magnatec to using the "Make The Switch" promo of PUP 0w20 of 1/4 qt over 5k miles and then none after that. Did 9-10k OCI with PUP 0w20 no issue.
 
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