HTHS for Rotella T5?

dnewton3

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IIRC Jim Allen has posted info that shows the T5 in 10w-30 and T6 5W-40 have essentially the same cold cranking rating. You can use 10w-30 T5, get the same cold starts, and save money over the more expensive T6.
 
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Originally Posted By: dnewton3
IIRC Jim Allen has posted info that shows the T5 in 10w-30 and T6 5W-40 have essentially the same cold cranking rating.
Interesting! Thanks.
 
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Originally Posted By: dnewton3
IIRC Jim Allen has posted info that shows the T5 in 10w-30 and T6 5W-40 have essentially the same cold cranking rating.
Actually T6 is lighter at temp's as high as 50F. [quote=dnewton3][/quote] "Conventional oil vs Synthetic oils isn't about which is better; it's about which lasts longer, in relation to cost." I couldn't disagree more. Syn' oils are "better" lubricants in many ways including cleanliness, but primarily due to their higher natural VIs which provide a lower start-up viscosity at all temp's.
 
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Originally Posted By: Quattro Pete
I'd probably run T6 in it - better for cold starts during winter.
But if you can get the vastly superior M1 0W-40 for 5 buck/qt on sale why buy the far heavier T6. Actually since the application is a VW beater, I'd just go with the cheapest 5W-30 dino for the winter. You're not going to see high oil temp's so don't need a 3.5cP oil.
 
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Originally Posted By: CATERHAM
Actually since the application is a VW beater, I'd just go with the cheapest 5W-30 dino for the winter.
I guess that was the OP's initial idea. The T5 he's considering must be cheaper than T6 and M1 0w-40 we've thrown out there.
 
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Yeah, T5 is $16/gal and T6 about $21 (USD). Going back to Dave Newton's comment above, I posted the CCS numbers of both a while back and they were in the same ballpark.
 
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Originally Posted By: CATERHAM
I couldn't disagree more. Syn' oils are "better" lubricants in many ways including cleanliness, but primarily due to their higher natural VIs which provide a lower start-up viscosity at all temp's.
Then following your assumption, the wear metals in comparable UOAs between synthetic oil and mineral oil should be significantly different when in fact they are similar and in many cases, show less wear metals with mineral oil. Please explain how you can make your statement when the UOA wear metal evidence contradicts it?
 
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Originally Posted By: BoiseRob
Then following your assumption, the wear metals in comparable UOAs between synthetic oil and mineral oil should be significantly different when in fact they are similar and in many cases, show less wear metals with mineral oil. Please explain how you can make your statement when the UOA wear metal evidence contradicts it?
You do realize that a $20 UOA is not a good tool for comparing oils, don't you?
 
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Originally Posted By: Quattro Pete
You do realize that a $20 UOA is not a good tool for comparing oils, don't you?
If synthetics are so much better in wear reduction, the UOAs would validate the results but they don't. How else do YOU compare real world results, by price? You realize price is not a good tool for comparing oils, don't you?
 
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Originally Posted By: BoiseRob
Originally Posted By: Quattro Pete
You do realize that a $20 UOA is not a good tool for comparing oils, don't you?
If synthetics are so much better in wear reduction, the UOAs would validate the results but they don't.
I never claimed that synthetics are so much better in wear reduction. They're better at keeping the engine clean, and they're better at longer oil change intervals. Let's compare a mineral oil against a synthetic oil, both changed at 10K mile intervals, for 200K miles in two identical engines. Then do a tear down and compare the cleanliness of each.
 
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^^that old gag! the imposible to complete test whistle at any rate, that is ONE reason I use a HD syn-blend is to keep my motor cleaner and to clean up what the PO possibly left behind. I love seeing the [censored] that comes out of a motor after a switch to HM, HDEO or some form of synthetic
 

dnewton3

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Engine cleanliness has little if anything to do with the base stock ... The detergent and dispersent (anti-agglomerate) portions of the additive package are what keep an engine clean. I suppose one could say that a syn has a "better" chance to clean, but that's only because they are designed for longer service intervals, and therefore get more of the additive package so they'll last longer. It's a self-fulfilling prophesey. However, it's been a while since I've pointed this out, so it bear repeating. Let's think this through, folks. Presuming we start with a reasonably clean engine, the rate at which the engine gets dirty (soot production, insolubles, etc) is reasonably constant. The engine will not get dirtier, quicker, just because you use a dino versus a syn. So, as long as the oil you've chosen can keep up with the contaminants, either oil should be able to clean decently and keep up with demand, so to speak. Analogy ... (I'm famous for them) ... You have a nice clean home. You and your wife are the only ones there. You have a maid come in once a week and clean. She does a good job, and that's all that's needed. Unless your grandkids come over and trash the place, more maids are not needed. Even if you had three maids come once a week (or the same maid three times a week) the contamination production level for you and your wife is fairly constant. Hiring more maids does not clean the house any "better" than what is needed. If the one maid for two people is sufficient, anything more than that is redundant. The extra maids cannot clean up what is not produced past the capacity of the first maid. Same with oils. A decent engine will not be "cleaner" from using syns under conventional OEM OCIs. Syn's can certainly clean "better" (better being defined as less residual) over longer OCIs because the additive package in a dino is overwhelmed sooner than in a syn. That's simply by design. In short, you cannot clean up what does not yet exist. Put some ficitious number to it if you want. Suppose an engine creates 35mg/L of contaminants over 5k miles. If the oil has an additive package that is superior to that, then the engine is going to be clean. If a dino can handle 45mg/L and a syn can handle 60mg/L, it's a moot point because both are more than adequate to handle the total contaminant load for the expected OCI. Now, if you were to push the OCI out to 10k miles, then the dino would be overwhelmed where the syn would succeed. But that is not the intent now, is it. The INTENT is to use any lube up to, but not past, it's capabilities. Be it wear, contaminants, TBN, vis, etc. Use a product to it's benefit, but not past. In practical application, the "cleanliness" of an engine is akin to the wear of an engine. As long as you don't use any lube past its capability, then it should perform about as well as any other lube. The thing with syns is that they are made to last "longer", not "better". I simply do not accept that a syn will "clean" an engine better simply by being present. Once again, it's about analyzing your operations, determining an OCI, and then picking a lube. Just like my signature says. If you want to artifically handicap the dino by pushing it past its fair limit, the same unreasonable act could be done to a syn. Syns don't last forever, they just last longer. In other words, I could use a syn for too long and make that engine dirty too. As long as you use a lube within its limits, a syn won't clean any "better", just longer ...
 
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Cleanliness does have a lot to do with the base stocks particularly with regard to varnish and coke formation. The better base stocks simply do not leave these deposits in the first place. It's one reason why syn' oils are preferred for turbo applications.
 
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Originally Posted By: CATERHAM
Cleanliness does have a lot to do with the base stocks particularly with regard to varnish and coke formation. The better base stocks simply do not leave these deposits in the first place. It's one reason why syn' oils are preferred for turbo applications.
I agree with the fact that a better dino or synthetic base stock leave less deposits to begin with.
 
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dnewton3, you know I agree with you most of the time. But why does MB require 228.5 oils for longest OCIs: http://bevo.mercedes-benz.com/bevolisten...ent_action=show Which are either full synthetics (Grp. III or IV) with a few synthetic blends, for its' longest OCIs: 1200 hrs in modern Unimogs without EGR, longer (I'm not sure how long, maybe 2400 hrs or ~100K mi) in Actros. I think the reasons are the following: synthetics are more resistant to coking in turbo bearings, also better at suspending particulate wastes like soot (esp Grp. IV PAOs). Also all the oils in that list have a TBN at least 12. And say whatever about TBN, but acids are made not only from sulfur but oxidation of nitrogen, which will always be with us (especially in Euro 4 and 5 and 6 engines that don't have EGR but rely on NOx-soot cats just before the DPF, and AdBlu). What I'm trying to say is that Grp. I and II bases get dirty as they age, not in 5 or 10000 mi but in 40-100,000 miles. Charlie
 
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