Is it true that most 5w30 conventional oils shear to 20wt after little use? The dinos that I usually use are MC5k and Havy DS 5w30. If this is true in those brands, I want to go ahead and use MC 5w-20, especially for the price with performance. Oh my engine calls for 5w30 too.
5W-30 Shear question
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I would say no, that statement is not true.
Some 5w30 conventionals shear to a high 20wt depending on the application it's used in and how it's used.
I've had 5W30 shear slightly, but never any into the 20wt region. Some have though.
Some 5w30 conventionals shear to a high 20wt depending on the application it's used in and how it's used.
I've had 5W30 shear slightly, but never any into the 20wt region. Some have though.
+1 Zaedock.
Most of the used oil analysis on 30 weight oil show them staying in grade. Occasionally, given the right engine and service life, one will shear down to a 20 weight.
Little use? No. 7500 miles perhaps.
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However ..5w30's ..of perhaps the same vintage as your car MAY have been more shear prone than those of today.
However ..5w30's ..of perhaps the same vintage as your car MAY have been more shear prone than those of today.
If your talking about your Q45, I'd be a little hesitant to put 5w20 in that. I'd stick with the nissan spec'd XXw30.
+1
My understanding is that oils will shear down and thin a bit.
But not after 'a little' use. More like 3k+, and not a big deal.
Dino is worse in this respect.
If an oil is really old and beat up, with abuse and heat, it can start to thicken. But this is way after an oil change is due, and is unusual.
But not after 'a little' use. More like 3k+, and not a big deal.
Dino is worse in this respect.
If an oil is really old and beat up, with abuse and heat, it can start to thicken. But this is way after an oil change is due, and is unusual.
Most of the bad shearing took place with older formulations with weaker base stocks and VI improvers. The new modern day oils are less likely to have the same shear rate. When the new GF-5 oils come out they will be even more shear stable. Use your 5w30.
Pleanty of used oil analysis on here to review. Not much shearing with modern oils.
Stick with 5w30, as mentioned above.
I've looked at 5w30 conventional shearing a few times. Seems most shear to 20W. Looking at five used oil analysis posted here today on the first page, the 5w30 conventionals sheared as follows:
Brand OCI 100C Vis.
QS 2800 8.2
Chev 4900 9.0
Val? 5300 9.2
GTX 2500 8.3
Shell 5200 8.8
SAE J300 specs 30W 100C Vis. as 9.3 min. So all 5 above sheared to 20W. Basically the same results I saw last time I looked.
Conversely, last time I looked, most syns stayed above 9.3 (30W)over the OCI.
Brand OCI 100C Vis.
QS 2800 8.2
Chev 4900 9.0
Val? 5300 9.2
GTX 2500 8.3
Shell 5200 8.8
SAE J300 specs 30W 100C Vis. as 9.3 min. So all 5 above sheared to 20W. Basically the same results I saw last time I looked.
Conversely, last time I looked, most syns stayed above 9.3 (30W)over the OCI.
Thanks for the replies. I'll stick with the 5w30 for my car!! I'm glad that I posted this because I was going to pick up a jug.
Originally Posted By: mechtech2
My understanding is that oils will shear down and thin a bit.
But not after 'a little' use. More like 3k+, and not a big deal.
conventional is worse in this respect.
If an oil is really old and beat up, with abuse and heat, it can start to thicken. But this is way after an oil change is due, and is unusual.
It appears to my untrained eye, in reading many used oil analysis, that many of the engines that tend to shear traditional 5w30 conventionals also tend to shear traditional conventional 10w30 oils as well. Would you agree with this?
My understanding is that oils will shear down and thin a bit.
But not after 'a little' use. More like 3k+, and not a big deal.
conventional is worse in this respect.
If an oil is really old and beat up, with abuse and heat, it can start to thicken. But this is way after an oil change is due, and is unusual.
It appears to my untrained eye, in reading many used oil analysis, that many of the engines that tend to shear traditional 5w30 conventionals also tend to shear traditional conventional 10w30 oils as well. Would you agree with this?
If you see energy conserving on the label, you can count on it shearing to a 20wt. If it doesn't, consider yourself lucky.
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Originally Posted By: Brian Barnhart
I've looked at 5w30 conventional shearing a few times. Seems most shear to 20W. Looking at five used oil analysis posted here today on the first page, the 5w30 conventionals sheared as follows:
Brand OCI 100C Vis.
QS 2800 8.2
Chev 4900 9.0
Val? 5300 9.2
GTX 2500 8.3
Shell 5200 8.8
SAE J300 specs 30W 100C Vis. as 9.3 min. So all 5 above sheared to 20W. Basically the same results I saw last time I looked.
Conversely, last time I looked, most syns stayed above 9.3 (30W)over the OCI.
How many were fuel diluted?
How many were turbo's?
Flashpoints?
Some engines appear to shear oils. The same oils don't "routinely" shear.
I've looked at 5w30 conventional shearing a few times. Seems most shear to 20W. Looking at five used oil analysis posted here today on the first page, the 5w30 conventionals sheared as follows:
Brand OCI 100C Vis.
QS 2800 8.2
Chev 4900 9.0
Val? 5300 9.2
GTX 2500 8.3
Shell 5200 8.8
SAE J300 specs 30W 100C Vis. as 9.3 min. So all 5 above sheared to 20W. Basically the same results I saw last time I looked.
Conversely, last time I looked, most syns stayed above 9.3 (30W)over the OCI.
How many were fuel diluted?
How many were turbo's?
Flashpoints?
Some engines appear to shear oils. The same oils don't "routinely" shear.
Originally Posted By: Gary Allan
Originally Posted By: Brian Barnhart
I've looked at 5w30 conventional shearing a few times. Seems most shear to 20W. Looking at five used oil analysis posted here today on the first page, the 5w30 conventionals sheared as follows:
Brand OCI 100C Vis.
QS 2800 8.2
Chev 4900 9.0
Val? 5300 9.2
GTX 2500 8.3
Shell 5200 8.8
SAE J300 specs 30W 100C Vis. as 9.3 min. So all 5 above sheared to 20W. Basically the same results I saw last time I looked.
Conversely, last time I looked, most syns stayed above 9.3 (30W)over the OCI.
How many were fuel diluted?
How many were turbo's?
Flashpoints?
Some engines appear to shear oils. The same oils don't "routinely" shear.
Gary,
Do you have data for any dino GF-4 5W30 that doesn't shear over a typical OCI in a most non-turbo engines it's used in?
Originally Posted By: Brian Barnhart
I've looked at 5w30 conventional shearing a few times. Seems most shear to 20W. Looking at five used oil analysis posted here today on the first page, the 5w30 conventionals sheared as follows:
Brand OCI 100C Vis.
QS 2800 8.2
Chev 4900 9.0
Val? 5300 9.2
GTX 2500 8.3
Shell 5200 8.8
SAE J300 specs 30W 100C Vis. as 9.3 min. So all 5 above sheared to 20W. Basically the same results I saw last time I looked.
Conversely, last time I looked, most syns stayed above 9.3 (30W)over the OCI.
How many were fuel diluted?
How many were turbo's?
Flashpoints?
Some engines appear to shear oils. The same oils don't "routinely" shear.
Gary,
Do you have data for any dino GF-4 5W30 that doesn't shear over a typical OCI in a most non-turbo engines it's used in?
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