People tell me that synthetic 5w40's like rotella 5w40 thin out quicker than say a rotella 15w40..is this nonsense?? They say that "group 3 " synthetics like this do more than "real" synthetics like amsoil and redline. What is the truth?? Please post UOA'S to back this up!
Does synthetic 5w40's thin out compared to....
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Do some research on this site, its called shearing. The Rotella before the T6 possibly had some shearing issues, however the new T6 has better VI's to help.
And to a point, they are correct. Once you have a wider spread, some oils need more VI's to cover it. Some Boutique oils like amsoil and redline use different base stocks as an alternative.
And to a point, they are correct. Once you have a wider spread, some oils need more VI's to cover it. Some Boutique oils like amsoil and redline use different base stocks as an alternative.
I've never had a problem...at least not visually on the oil psi gauge. If it had sheared, I'm sure I would see some kind of psi drop somewhere along the line. My oil psi is always consistent-in the Jeep that is because the VW has no oil psi gauge.
Originally Posted By: Bigsyke
Do some research on this site, its called shearing. The Rotella before the T6 possibly had some shearing issues, however the new T6 has better VI's to help.
And to a point, they are correct. Once you have a wider spread, some oils need more VI's to cover it. Some Boutique oils like amsoil and redline use different base stocks as an alternative.
my rotella t6 5w40 has sheared to a 11.89 cst @100C. after 3000 miles and 4 qts of take up
Do some research on this site, its called shearing. The Rotella before the T6 possibly had some shearing issues, however the new T6 has better VI's to help.
And to a point, they are correct. Once you have a wider spread, some oils need more VI's to cover it. Some Boutique oils like amsoil and redline use different base stocks as an alternative.
my rotella t6 5w40 has sheared to a 11.89 cst @100C. after 3000 miles and 4 qts of take up
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With 4qts. of make-oil in 3K I would get something fixed.
I have had 5w40 oils shear out of grade on several UOA's. In one case, I idled down a large tractor and the low oil pressure warning light came on. That light had never come on previously, and it never did again after I switched the engine back to 15w40.
Originally Posted By: Rob_Roy
I have had 5w40 oils shear out of grade on several UOA's. In one case, I idled down a large tractor and the low oil pressure warning light came on. That light had never come on previously, and it never did again after I switched the engine back to 15w40.
Which 5w40 and 15w40 was this?
There's no doubt most 15w40s have higher HTHS than most 5w40s.
I have had 5w40 oils shear out of grade on several UOA's. In one case, I idled down a large tractor and the low oil pressure warning light came on. That light had never come on previously, and it never did again after I switched the engine back to 15w40.
Which 5w40 and 15w40 was this?
There's no doubt most 15w40s have higher HTHS than most 5w40s.
Originally Posted By: BobFout
Which 5w40 and 15w40 was this?
There's no doubt most 15w40s have higher HTHS than most 5w40s.
In the case of the low oil pressure light, both oils were Rotella products. I quit using Rotella altogether after a hot running (but within limits) 8.3L Cummins ate its camshaft and tappets. This was 4-5 years ago, so I can't comment on the performance of the current formulations.
The only other 5w40 that I've used was Schaeffer 9000; it also sheared to a SAE 30 in the JD tractors.
Which 5w40 and 15w40 was this?
There's no doubt most 15w40s have higher HTHS than most 5w40s.
In the case of the low oil pressure light, both oils were Rotella products. I quit using Rotella altogether after a hot running (but within limits) 8.3L Cummins ate its camshaft and tappets. This was 4-5 years ago, so I can't comment on the performance of the current formulations.
The only other 5w40 that I've used was Schaeffer 9000; it also sheared to a SAE 30 in the JD tractors.
Originally Posted By: SpecificationR
my rotella t6 5w40 has sheared to a 11.89 cst @100C. after 3000 miles and 4 qts of take up
At least mention how bad your tuning is and you probably had 2% or more fuel dilution.
You never see 5W-40 RTS shear that low on its own.
From looking at many, many UOA's over time, I've seen that RTS 5W-40 (not talking about T6) shears down to the 13.5cst range on average. Never less, sometimes higher. I can't call [censored], but there are a lot of Shell haters. I don't see how just RTS 5W-40 caused problems when in every single individual UOA, whether gasoline or diesel, turbo or NA, it brings back stellar results.
It was because of these results I started using it. It goes in a GM LS1 V8, a Ford 5.0 EFI V8, a Mitsu 2.4 SOHC 4 cyl, a GM 3800II V6, two lawnmowers, one pushmower, and a weed-eater. I believe that if this oil had a formulation problem, I would be the first to experience it. I am not easy on anything, and I actually am harder than normal on my vehicles because I think the oil is great.
my rotella t6 5w40 has sheared to a 11.89 cst @100C. after 3000 miles and 4 qts of take up
At least mention how bad your tuning is and you probably had 2% or more fuel dilution.
You never see 5W-40 RTS shear that low on its own.
From looking at many, many UOA's over time, I've seen that RTS 5W-40 (not talking about T6) shears down to the 13.5cst range on average. Never less, sometimes higher. I can't call [censored], but there are a lot of Shell haters. I don't see how just RTS 5W-40 caused problems when in every single individual UOA, whether gasoline or diesel, turbo or NA, it brings back stellar results.
It was because of these results I started using it. It goes in a GM LS1 V8, a Ford 5.0 EFI V8, a Mitsu 2.4 SOHC 4 cyl, a GM 3800II V6, two lawnmowers, one pushmower, and a weed-eater. I believe that if this oil had a formulation problem, I would be the first to experience it. I am not easy on anything, and I actually am harder than normal on my vehicles because I think the oil is great.
i used the 5w-40 (pre t6) in my 6.0 powerstroke for 2 oci and uoa results were terrible, sheared down to mid 30wt grade and wear numbers were noticebly higher compared to the deere plus 50 15w-40.
i know the 6.0 is known to shear motor oil, but i had a good comparision, after running it 2 consecitive oc, went back to the plus 50 and wear numbers returned to where they were.
after stating above, i think shell addressed a problem with the prior formulation, hence the t6.
i won't run it any longer, but the uoa's i have seen posted here look like the t6 is an improvement. i don't consider myself a "shell hater", just posting what my own uoa's have shown me.
i know the 6.0 is known to shear motor oil, but i had a good comparision, after running it 2 consecitive oc, went back to the plus 50 and wear numbers returned to where they were.
after stating above, i think shell addressed a problem with the prior formulation, hence the t6.
i won't run it any longer, but the uoa's i have seen posted here look like the t6 is an improvement. i don't consider myself a "shell hater", just posting what my own uoa's have shown me.
Originally Posted By: Jaymus
Originally Posted By: SpecificationR
my rotella t6 5w40 has sheared to a 11.89 cst @100C. after 3000 miles and 4 qts of take up
At least mention how bad your tuning is and you probably had 2% or more fuel dilution.
You never see 5W-40 RTS shear that low on its own.
there were at least 30 3rd gear dyno runs on the oil, and the tune is actually pretty good. im not blaming T6, but i'm not blaming my current tune or engine set up either. there are plenty of unforeseen factors at play. I'll get another UOA in the next couple of months.
here's my other thread.
http://www.bobistheoilguy.com/forums/ubb...230#Post1931230
Originally Posted By: SpecificationR
my rotella t6 5w40 has sheared to a 11.89 cst @100C. after 3000 miles and 4 qts of take up
At least mention how bad your tuning is and you probably had 2% or more fuel dilution.
You never see 5W-40 RTS shear that low on its own.
there were at least 30 3rd gear dyno runs on the oil, and the tune is actually pretty good. im not blaming T6, but i'm not blaming my current tune or engine set up either. there are plenty of unforeseen factors at play. I'll get another UOA in the next couple of months.
here's my other thread.
http://www.bobistheoilguy.com/forums/ubb...230#Post1931230
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