increase in consumption after changing oil brands

Status
Not open for further replies.
F

friendly_jacek

Joined
May 4, 2003
Messages
6,619
Location
southeast US
I was always puzzled by this and experienced that myself. according to http://www.corrosioncontrol.net/motoroil_faq.htm
Quote:
There is usually an increase in consumption after changing oil brands. In this scenario, it is usually only for a short period of time and then returns to its previous low level. The change occurs because motor oils differ in additive packages, which make up about 20% of the product. This change in the detergent/dispersant chemistry tends to remove previously deposited material that is helping to seal. Once this deposit is removed, the new chemistry will produce a deposit that regains full sealing benefits and controls oil consumption to the original lower level. Any increased oil consumption not related to these circumstances is generally due to a mechanical problem.
Are they talking about valve-steam seal? Also, I'm skeptical as most additives are very similar: ZDDP, Moly, calcium sulfonate, etc.
 
I wouldn't exactly say "impossible," but until someone shows me some scanning electron microscope images of these alleged additive deposits which help seal, then I'm really hard pressed to believe in them. I've never experienced a consumption jump when changing brands personally, so I tend to believe its halo effect- observing what you EXPECT to observe- coupled with the fact that a dipstick is a pretty imprecise measuring tool since its reading can be altered by a change in oil temperature, a difference in time between shutdown and reading, the tilt of the land, etc. etc. etc.
 
No, it's real. Once I lost 0.5 qt of oil immediately after oil change with different brand with higher viscosity and detergent levels (HDEO) in a relatively new car with 0 oil consumption before and after. According to Valvoline FAQ it happens only in 5-10% of cases:
Quote:
I converted the customer from 'Company X' to Valvoline and the customer reported sudden increase in oil consumption. Is my product at fault? This classic complaint can happen in 5-10% cases when changing brands of motor oils. This has been occurring for years, and can occur when changing from one brand to the other (same company), as well as one company to another. Remember, in all such changes, increase in consumption of oil is observed for a short period of time (1-2 change intervals), and then returns to the previous low level. Interestingly, if one returns to the original brand, higher oil consumption is again observed! Top
 
I had it happen once, when I first dumped a Mobil 1/Mobil Super blend in my wifes Chevy it gobbled up 3/4 of a quart the first 500 miles. The vehicle normally needs no top offs during an OCI. After about 750 miles the consumption returned to nearly nothing. Previously it had a steady diet of mostly Castrol but there were others. I change brands a lot but that's the only time any of my vehicles has done that...so it can happen but it's certainly not a given.
 
Originally Posted By: 440Magnum
... but until someone shows me some scanning electron microscope images of these alleged additive deposits which help seal, then I'm really hard pressed to believe in them...
You're in luck. You're talking to such a guy. I operate a scanning electron microscope and I look at sealing surfaces - both sides. Your assumption is correct and there are no such deposits on the sealing surface. It's the thin layer of oil that does the sealing. Deposits on sealing surfaces are never a good sign.
 
Originally Posted By: Kestas
I operate a scanning electron microscope and I look at sealing surfaces - both sides. Your assumption is correct and there are no such deposits on the sealing surface. It's the thin layer of oil that does the sealing. Deposits on sealing surfaces are never a good sign.
What sealing surfaces are those?
 
How about this theory: Since new oil increases wear, the rings/cylinder interface need to break in into a new layer of metal exposed after oil change?
 
Originally Posted By: friendly_jacek
How about this theory: Since new oil increases wear, the rings/cylinder interface need to break in into a new layer of metal exposed after oil change?
Since when???
 
So in reality we need to be recycling old oil amongst ourselves and make our own addpacks/additives ? That link is new to me.
 
Last edited:
OR If someone wants to come pick up my Penn Ultra after 3K changes... It's all yours. I'll even have it put in the new container ready for you.
 
I had it happen in a Mazda V-6. Used Castrol GTX 5W30 and went to Pep Boys private label (I forget the name back then). It was API approved and correct for the engine. From no oil usage to one quart in 3,000 miles. I thought it a fluke and used it again with the very same outcome......went back to the previous oil and it never used any again. It can and does happen!
 
Originally Posted By: PZR2874
So in reality we need to be recycling old oil amongst ourselves and make our own addpacks/additives ? That link is new to me.
LOL I used to change oil in my "good" cars at 1500mi just to feed the appetite of a beater(bought used with a dubious history), that was using a quart in about 500 miles... Interestingly after a year or so, it dropped to less than a quart in 2K and "earned" it's own fresh changes, which made no further improvement... I read most of the info in that link, chances I'm gonna believe fresh oil is a "downgrade" vs used is zero & none...
 
Originally Posted By: TFB1
I read most of the info in that link, chances I'm gonna believe fresh oil is a "downgrade" vs used is zero & none...
so is other words, you'll stick with belief over knowledge. Interesting.
 
^I don't think that's what he meant. Take MY Speed for instance.... I'd rather introduce fresh oil every 3k than have X% of fuel dilution. my 2¢ EDIT: Especially when I can feel the difference in the performance from the OC
 
Last edited:
Its been reported before and can take upto 3 OCIs before it returns to nornmal depending how bad the varnish buildup is. Clogging of the oil filter from the varnish removal process often is doesn't help either as it may so clogged that the oil filter into bypass mode. Several oil filter changes maybe required in first OCIs.
 
Last edited:
Status
Not open for further replies.

Similar threads

paulri
How does blowby gas increase oil consumption?
2
Replies
28
Views
2K
chris719
T
Rate of Oil Consumption - Increases with Oil Aging?
Replies
12
Views
926
paulri
paulri
What causes oil consumption to progress, further into the OCI?
2
Replies
31
Views
3K
Stumpy
O
Which of the major brands have foil seals on their 5 quart bottles?
2
Replies
20
Views
895
bbhero
O
Another Youtuber trying HPL trying to stop Oil Consumption
2 3 4
Replies
64
Views
2K
buster
Top