Classic car oil
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Originally Posted By: 05LGTLtd
Widman graph is not the end all to accuracy, but I double dog dare you to tell me there is any real world difference in the performance of these two oils in the context of the the OP's use:
http://www.epc.shell.com/Docs/GPCDOC_Local_TDS_United_States_Shell_Rotella_T5_0W-30_%28CH-4%29_%28en-US%29_TDS_v1.pdf
http://www.epc.shell.com/Docs/GPCDOC_X_cbe_24855_key_140007079163_201203220846.pdf
(Yes I left a '0' out and it should be 68.02 not 68.2, not going to go back and change it now)
The Rotella spec's you've provided are incorrect especially the the KV40 of 65cSt as the net VI would be an impossible 180.
The following PDS gives a more realistic KV40 of 78.89cSt and KV100 of 12cSt with a VI of 147:
http://theoilnet.com/Atlantic-States-Lub...10W30-10W40.pdf
More importantly, T5 has a HTHSV of 3.5cP while Defy 5w30 is likely no higher than 3.2-3.3cP. That in conjunction with it's higher 163 VI translates into an oil that is significantly lighter at all temperatures and particularly on start-up.
Widman graph is not the end all to accuracy, but I double dog dare you to tell me there is any real world difference in the performance of these two oils in the context of the the OP's use:
http://www.epc.shell.com/Docs/GPCDOC_Local_TDS_United_States_Shell_Rotella_T5_0W-30_%28CH-4%29_%28en-US%29_TDS_v1.pdf
http://www.epc.shell.com/Docs/GPCDOC_X_cbe_24855_key_140007079163_201203220846.pdf
(Yes I left a '0' out and it should be 68.02 not 68.2, not going to go back and change it now)
The Rotella spec's you've provided are incorrect especially the the KV40 of 65cSt as the net VI would be an impossible 180.
The following PDS gives a more realistic KV40 of 78.89cSt and KV100 of 12cSt with a VI of 147:
http://theoilnet.com/Atlantic-States-Lub...10W30-10W40.pdf
More importantly, T5 has a HTHSV of 3.5cP while Defy 5w30 is likely no higher than 3.2-3.3cP. That in conjunction with it's higher 163 VI translates into an oil that is significantly lighter at all temperatures and particularly on start-up.
Ok, here's the graph with correct numbers"
Sorry about that.
Originally Posted By: CATERHAM
More importantly, T5 has a HTHSV of 3.5cP while Defy 5w30 is likely no higher than 3.2-3.3cP. That in conjunction with it's higher 163 VI translates into an oil that is significantly lighter at all temperatures and particularly on start-up.
What gets me about the "too thick" argument is that at the temps given by the OP the actual differences are pretty much irrelevant. If he originally stated that he starts his car year round at 32*F, you would still say that the defy 5w30 was a good choice. Well at 40*F that T5 is no thicker than the Defy would be at 32*F. OP is not trying to optimize economy in this application as far as we know. (Not that I think you could measure an economy difference between these two oils in this application.) Even at 40*, within a minute or two of idle, the oils are so near identical it's meaningless. I'd guess the vast majority of his starts are above 50*F in this Classic Mustang, making it even less relevant.
Yes The T5 is a "thicker" oil, but in this case both the oils are acceptable. They both have good AW packs, they both will perform within the prescribed parameters. Saying one is better than the other is splitting unnecessary hairs, imho.
Sorry about that.
Originally Posted By: CATERHAM
More importantly, T5 has a HTHSV of 3.5cP while Defy 5w30 is likely no higher than 3.2-3.3cP. That in conjunction with it's higher 163 VI translates into an oil that is significantly lighter at all temperatures and particularly on start-up.
What gets me about the "too thick" argument is that at the temps given by the OP the actual differences are pretty much irrelevant. If he originally stated that he starts his car year round at 32*F, you would still say that the defy 5w30 was a good choice. Well at 40*F that T5 is no thicker than the Defy would be at 32*F. OP is not trying to optimize economy in this application as far as we know. (Not that I think you could measure an economy difference between these two oils in this application.) Even at 40*, within a minute or two of idle, the oils are so near identical it's meaningless. I'd guess the vast majority of his starts are above 50*F in this Classic Mustang, making it even less relevant.
Yes The T5 is a "thicker" oil, but in this case both the oils are acceptable. They both have good AW packs, they both will perform within the prescribed parameters. Saying one is better than the other is splitting unnecessary hairs, imho.
Originally Posted By: 05LGTLtd
Ok, here's the graph with correct numbers"
Sorry about that.
Originally Posted By: CATERHAM
More importantly, T5 has a HTHSV of 3.5cP while Defy 5w30 is likely no higher than 3.2-3.3cP. That in conjunction with it's higher 163 VI translates into an oil that is significantly lighter at all temperatures and particularly on start-up.
What gets me about the "too thick" argument is that at the temps given by the OP the actual differences are pretty much irrelevant. If he originally stated that he starts his car year round at 32*F, you would still say that the defy 5w30 was a good choice. Well at 40*F that T5 is no thicker than the Defy would be at 32*F. OP is not trying to optimize economy in this application as far as we know. (Not that I think you could measure an economy difference between these two oils in this application.) Even at 40*, within a minute or two of idle, the oils are so near identical it's meaningless. I'd guess the vast majority of his starts are above 50*F in this Classic Mustang, making it even less relevant.
Yes The T5 is a "thicker" oil, but in this case both the oils are acceptable. They both have good AW packs, they both will perform within the prescribed parameters. Saying one is better than the other is splitting unnecessary hairs, imho.
There is no "splitting hairs" here as your reasoning is flawed.
QS Defy 5w30 is 20% lighter at room temperature and more so at lower temp's . Rotella 10w30 is almost a 40 wt oil and is simply way heavier than necessary. Heck, even Mobil 1 0W-40 is 15% lighter than Rotella at room temperature and no one is suggesting the OP run that.
Ok, here's the graph with correct numbers"
Sorry about that.
Originally Posted By: CATERHAM
More importantly, T5 has a HTHSV of 3.5cP while Defy 5w30 is likely no higher than 3.2-3.3cP. That in conjunction with it's higher 163 VI translates into an oil that is significantly lighter at all temperatures and particularly on start-up.
What gets me about the "too thick" argument is that at the temps given by the OP the actual differences are pretty much irrelevant. If he originally stated that he starts his car year round at 32*F, you would still say that the defy 5w30 was a good choice. Well at 40*F that T5 is no thicker than the Defy would be at 32*F. OP is not trying to optimize economy in this application as far as we know. (Not that I think you could measure an economy difference between these two oils in this application.) Even at 40*, within a minute or two of idle, the oils are so near identical it's meaningless. I'd guess the vast majority of his starts are above 50*F in this Classic Mustang, making it even less relevant.
Yes The T5 is a "thicker" oil, but in this case both the oils are acceptable. They both have good AW packs, they both will perform within the prescribed parameters. Saying one is better than the other is splitting unnecessary hairs, imho.
There is no "splitting hairs" here as your reasoning is flawed.
QS Defy 5w30 is 20% lighter at room temperature and more so at lower temp's . Rotella 10w30 is almost a 40 wt oil and is simply way heavier than necessary. Heck, even Mobil 1 0W-40 is 15% lighter than Rotella at room temperature and no one is suggesting the OP run that.
I'd recommend Rotella or Delo 10w30, but really any modern 10w30 will be just fine.
Now i am really confused.
My 68 camaro w/ a 250 6 cylinder. Is used spring and summer.i usually use 30w diesel that my neighbor has is a 55 gallon barrel. Oil is probally 20 Yeats old.
Is this ok or what should I change to?
My 68 camaro w/ a 250 6 cylinder. Is used spring and summer.i usually use 30w diesel that my neighbor has is a 55 gallon barrel. Oil is probally 20 Yeats old.
Is this ok or what should I change to?
I'd bet that a straight thirty was among the grades originally recommended for warm weather use in this engine.
Doesn't make it optimal, but does make it workable.
I doubt that you're doing the engine any harm.
Just avoid romping on it (not that this engine has a lot to romp on) until the oil is warmed up.
I don't think that these old, low performance sixes have any special oil requirements.
When we had an old Chevy inline six, it just got whatever 10W-40 I could find cheap and it seemed perfectly content.
Of course, that was thirty years ago.
Doesn't make it optimal, but does make it workable.
I doubt that you're doing the engine any harm.
Just avoid romping on it (not that this engine has a lot to romp on) until the oil is warmed up.
I don't think that these old, low performance sixes have any special oil requirements.
When we had an old Chevy inline six, it just got whatever 10W-40 I could find cheap and it seemed perfectly content.
Of course, that was thirty years ago.
How about Defy 5w30 or something like that?
QS Defy 10w30 and quality filter such as MC FL1A or NAPA Gold 1515.
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