Synthetic oil vs Conventional oil
Diesel Oil Tests
See 540 Rat the Mechanical Engineer .See his Diesel Engine Oil Analysis for Diesel Trucks
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motoroiltests.com Diesel Oil
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I always found it a bit curious that some folks would use Diesel oil in High Performance gasoline engines, rather than the more obvious high quality gas engine oils. I assumed they figured that Diesel oils had higher zinc levels which most folks "mistakenly thought" was needed. Or maybe they figured if that oil works well for hard working Diesel engines, then it should work for their gas engines as well. But, other than some lab test reports showing zinc quantities, I haven’t seen much real data on any of that.
Is it possible that the Diesel oil fans somehow know more than the Oil Companies' Chemical Engineers and Chemists? But, based on only a casual overview, the value of using Diesel oil in gas engines seemed to be mostly just folklore that had been repeated over and over, without any real data to support that. So, since I’ve been performing a lot of motor oil testing this year, I thought is was time to do some extensive testing on Diesel oil, to see once and for all, just what the Diesel oil hype is all about.
So, finally, on with the Diesel Oil test data:
*** First I’d like to thank Mic (64 CDNSS on the Chevelle Forum) for being good enough to provide an unopened bottle of the “OLD” Rotella T Diesel oil, which many folks consider the Holy Grail of Diesel oils, and that it is the standard by which all other Diesel oils are judged. Without this oil’s numbers, we would have never known how the old and new Diesel oils compare.
*** The higher the psi result, the higher the “Load carrying capacity/Film strength”, and the better the oil is at preventing wear.
*** All oils were tested at 230* F (representative of actual running temperature).
*** Multiple tests were performed on each oil, and those results were averaged to arrive at each oil's final value shown below.
*** Test Result differences between oils of less than 10%, are not significant, and oils within that range can be considered approximately equivalent.
*** All oil bottles were thoroughly shaken before the samples were taken. This ensured that all the additive package components were distributed uniformly throughout all the oil in the bottle, and not settled to the bottom.
*** All the oils here are current new oils, recently purchased, except for the unopened OLD Rotella T mentioned above.
*** The onset of "Thermal Breakdown" is determined by the temperature at which the oil begins to smoke/vaporize. This indicates that the lighter components in the oil are beginning to boil off, which changes the oil's chemical composition for the worse. Always keep your oil below the point of thermal breakdown. If your oil does get too hot, then change it at your earliest convenience.
*** Lab Testing for component quantities shown below, was performed by ALS Tribology (formerly Staveley Labs) in Sparks, Nevada.
*** Diesel engine oils have C-type API certification rating designations. The “C” is in reference to “C”ompression ignition engines.
Gas engine oils have S-type API certification rating designations. The “S” is in reference to “S”park ignition engines.
Here are the 12 Diesel Oils that were tested. And they are ranked in the order of their “Load Carrying Capacity/Film Strength” values:
Is it possible that the Diesel oil fans somehow know more than the Oil Companies' Chemical Engineers and Chemists? But, based on only a casual overview, the value of using Diesel oil in gas engines seemed to be mostly just folklore that had been repeated over and over, without any real data to support that. So, since I’ve been performing a lot of motor oil testing this year, I thought is was time to do some extensive testing on Diesel oil, to see once and for all, just what the Diesel oil hype is all about.
So, finally, on with the Diesel Oil test data:
*** First I’d like to thank Mic (64 CDNSS on the Chevelle Forum) for being good enough to provide an unopened bottle of the “OLD” Rotella T Diesel oil, which many folks consider the Holy Grail of Diesel oils, and that it is the standard by which all other Diesel oils are judged. Without this oil’s numbers, we would have never known how the old and new Diesel oils compare.
*** The higher the psi result, the higher the “Load carrying capacity/Film strength”, and the better the oil is at preventing wear.
*** All oils were tested at 230* F (representative of actual running temperature).
*** Multiple tests were performed on each oil, and those results were averaged to arrive at each oil's final value shown below.
*** Test Result differences between oils of less than 10%, are not significant, and oils within that range can be considered approximately equivalent.
*** All oil bottles were thoroughly shaken before the samples were taken. This ensured that all the additive package components were distributed uniformly throughout all the oil in the bottle, and not settled to the bottom.
*** All the oils here are current new oils, recently purchased, except for the unopened OLD Rotella T mentioned above.
*** The onset of "Thermal Breakdown" is determined by the temperature at which the oil begins to smoke/vaporize. This indicates that the lighter components in the oil are beginning to boil off, which changes the oil's chemical composition for the worse. Always keep your oil below the point of thermal breakdown. If your oil does get too hot, then change it at your earliest convenience.
*** Lab Testing for component quantities shown below, was performed by ALS Tribology (formerly Staveley Labs) in Sparks, Nevada.
*** Diesel engine oils have C-type API certification rating designations. The “C” is in reference to “C”ompression ignition engines.
Gas engine oils have S-type API certification rating designations. The “S” is in reference to “S”park ignition engines.
Here are the 12 Diesel Oils that were tested. And they are ranked in the order of their “Load Carrying Capacity/Film Strength” values:
RED LINE, 15W40 Diesel Oil, synthetic
1. RED LINE, 15W40 Diesel Oil, synthetic, API CJ-4/CI-4 PLUS/CI-4/CF/CH-4/CF-4/SM/SL/SH/EO-O
“Load Carrying Capacity/Film Strength” = 85,663 psi
zinc = 1615 ppm
phos = 1551 ppm
moly = 173 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 2999 ppm
TBN = 8.3
The onset of thermal breakdown is approximately 285*
“Load Carrying Capacity/Film Strength” = 85,663 psi
zinc = 1615 ppm
phos = 1551 ppm
moly = 173 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 2999 ppm
TBN = 8.3
The onset of thermal breakdown is approximately 285*
ROYAL PURPLE, 15W40 Diesel Oil, synthetic
2. ROYAL PURPLE, 15W40 Diesel Oil, synthetic, API CJ-4 /SM, CI-4 PLUS, CH-4, CI-4
“Load Carrying Capacity/Film Strength” = 76,997 psi
zinc = TBD
phos = TBD
moly = TBD
total detergent/dispersant/anti-deposit build-up/anti-sludge = TBD TBN = TBD
The onset of thermal breakdown is approximately 265*
“Load Carrying Capacity/Film Strength” = 76,997 psi
zinc = TBD
phos = TBD
moly = TBD
total detergent/dispersant/anti-deposit build-up/anti-sludge = TBD TBN = TBD
The onset of thermal breakdown is approximately 265*
MOBIL 1 TURBO DIESEL TRUCK, 5W40 synthetic
3. MOBIL 1 TURBO DIESEL TRUCK, 5W40 synthetic, API CJ-4, CI-4 Plus, CI-4, CH-4 and ACEA E7
“Load Carrying Capacity/Film Strength” = 74,312 psi
zinc = 1211 ppm
phos = 1168 ppm
moly = 2 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 1596 ppm
TBN = 9.3
The onset of thermal breakdown is approximately 270*
“Load Carrying Capacity/Film Strength” = 74,312 psi
zinc = 1211 ppm
phos = 1168 ppm
moly = 2 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 1596 ppm
TBN = 9.3
The onset of thermal breakdown is approximately 270*
CHEVRON DELO 400XSP, 15W40 conventional
4. CHEVRON DELO 400XSP, 15W40 conventional, API CJ-4, CI-4 Plus, CI-4, CH-4, SM, SL, “Load Carrying Capacity/Film Strength” = 73,520 psi
zinc = 1519 ppm
phos = 1139 ppm
moly = 80 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 2205 ppm
TBN = 8.0
The onset of thermal breakdown is approximately 265*
zinc = 1519 ppm
phos = 1139 ppm
moly = 80 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 2205 ppm
TBN = 8.0
The onset of thermal breakdown is approximately 265*
MOBIL DELVAC 1300 SUPER, 15W40 conventional
5. MOBIL DELVAC 1300 SUPER, 15W40 conventional, API CJ-4, CI-4 Plus, CI-4, CH-4/SM, SL , “Load Carrying Capacity/Film Strength” = 73,300 psi
zinc = 1297 ppm
phos = 944 ppm
moly = 46 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 1843 ppm
TBN = 9.8
The onset of thermal breakdown is approximately 250*
zinc = 1297 ppm
phos = 944 ppm
moly = 46 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 1843 ppm
TBN = 9.8
The onset of thermal breakdown is approximately 250*
SHELL ROTELLA T4, 15W40 conventional
6. SHELL ROTELLA T4, 15W40 conventional, API CJ-4, CI-4 Plus, CH-4, CG-4, CF-4,CF/SM
“Load Carrying Capacity/Film Strength” = 72,022 psi
zinc = 1454 ppm
phos = 1062 ppm
moly = 0 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 2886 ppm
TBN = 9.1
The onset of thermal breakdown is approximately 250*
NOTE: This new Rotella T has SIGNIFICANTLY MORE zinc than the OLD Rotella T, NOT LESS as is often claimed. And these two Rotella oils were Lab tested more than a month apart. So, their component quantities had no chance of being mixed up. This new Rotella’s wear protection capability is just slightly BETTER than the OLD Rotella. Therefore, the new Rotella is NOT the junk some have claimed.
7. “OLD” SHELL ROTELLA T, 15W40 conventional, API CI-4 PLUS, CI-4, CH-4,CG-4,CF-4,CF,SL, SJ, SH
“Load Carrying Capacity/Film Strength” = 71,214 psi
zinc = 1171 ppm
phos = 1186 ppm
moly = 0 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 2715 ppm
TBN = 10.1
The onset of thermal breakdown is approximately 250*
NOTE: There is ABSOLUTELY NOTHING special about this OLD Rotella, as so many have always claimed. That was only folklore. It is simply ordinary Diesel oil.
VALVOLINE PREMIUM BLUE HEAVY DUTY DIESEL
8. VALVOLINE PREMIUM BLUE HEAVY DUTY DIESEL, 15W40 conventional, API CJ-4, CI-4 Plus, CI-4, CH-4, CG-4, CF-4, CF/SM
“Load Carrying Capacity/Film Strength” = 70,869 psi
zinc = TBD
phos = TBD
moly = TBD
total detergent/dispersant/anti-deposit build-up/anti-sludge = TBD
TBN = TBD
The onset of thermal breakdown is approximately 255*
CHEVRON DELO 400XSP, 5W40 synthetic,
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9. CHEVRON DELO 400XSP, 5W40 synthetic, API CJ-4, CI-4 Plus, CI-4, SL, SM,
“Load Carrying Capacity/Film Strength” = 69,631 psi zinc = TBD phos = TBD moly = TBD total detergent/dispersant/anti-deposit build-up/anti-sludge = TBD TBN = TBD The onset of thermal breakdown is approximately 255* |
SHELL ROTELLA T6, 5W40 synthetic
10. SHELL ROTELLA T6, 5W40 synthetic, API CJ-4, CI-4 Plus, CI-4, CH-4, CG-4/SM
“Load Carrying Capacity/Film Strength” = 67,804 psi
zinc = TBD
phos = TBD
moly = TBD
total detergent/dispersant/anti-deposit build-up/anti-sludge = TBD
TBN = TBD
The onset of thermal breakdown is approximately 260*
“Load Carrying Capacity/Film Strength” = 67,804 psi
zinc = TBD
phos = TBD
moly = TBD
total detergent/dispersant/anti-deposit build-up/anti-sludge = TBD
TBN = TBD
The onset of thermal breakdown is approximately 260*
LUCAS 15W40 MAGNUM Diesel Oil, conventional
11. LUCAS 15W40 MAGNUM Diesel Oil, conventional, API CI-4,CH-4, CG-4, CF-4, CF/SL
“Load Carrying Capacity/Film Strength” = 66,476 psi
zinc = 1441 ppm
phos = 1234 ppm
moly = 76 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 3393 ppm
TBN = 11.7
The onset of thermal breakdown is approximately 250*
“Load Carrying Capacity/Film Strength” = 66,476 psi
zinc = 1441 ppm
phos = 1234 ppm
moly = 76 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 3393 ppm
TBN = 11.7
The onset of thermal breakdown is approximately 250*
CASTROL GTX DIESEL, 15W40 conventional
12. CASTROL GTX DIESEL, 15W40 conventional, API CJ-4, CI-4 Plus, CI-4, CH-4, CG-4, CF-4/SN
“Load Carrying Capacity/Film Strength” = 66,323 psi
zinc = TBD
phos = TBD
moly = TBD
total detergent/dispersant/anti-deposit build-up/anti-sludge TBD
TBN = TBD
The onset of thermal breakdown is approximately 265*
“Load Carrying Capacity/Film Strength” = 66,323 psi
zinc = TBD
phos = TBD
moly = TBD
total detergent/dispersant/anti-deposit build-up/anti-sludge TBD
TBN = TBD
The onset of thermal breakdown is approximately 265*
The average value for Thermal Breakdown among the conventional Diesel oils here, was 255*, which is 17* LOWER than among the conventional gas engine oils I've tested.
The average value for Thermal Breakdown among the synthetic Diesel oils here, was 267*, which is 15* LOWER than among the synthetic gas engine oils I've tested.
And as you can see with these Diesel oils above, zinc levels alone do NOT establish their wear prevention ranking. The zinc levels are randomly up and down, relative to the ranking order. And as you will see in the complete 61 motor oil ranking list below, zinc levels clearly have NOTHING to do with an oil's protection capability or ranking order. Also, anyone who has followed my motor oil testing this year, probably noticed that these Diesel oil “Load Carrying Capacity/Film Strength” psi values are rather low, with an average value for the whole group of only 72,408 psi. This number would put an oil for gasoline engines, only in the MODEST PROTECTION category (60,000 to 75,000 psi). And individually, Red Line, the top ranked Diesel oil, ranks only 33rd out of 61 oils I’ve tested so far. The Red Line and Royal Purple, are the only Diesel oils to even make it into the GOOD PROTECTION category (75,000 to 90,000 psi) for use in gasoline engines. Overall that’s not very impressive to say the least, when you consider how wonderful many people “thought” Diesel oil was.
And considering that these oils are intended for use in heavy duty working Diesel engines as used in big rigs, bulldozers, locomotives, etc, etc, you probably expected to see some rather impressive psi numbers. But, if you were expecting that, you were obviously disappointed and maybe even shocked.
The oil testing equipment and the test procedure used here, were working perfectly fine, with no issue at all. In fact, in the middle of testing all these Diesel oils, I performed what you might call a calibration check, by re-testing once again, the number one ranked gas engine oil, the 5W30 Pennzoil Ultra, API SM, to see if its numbers would be reproduced within the normal variation range. And in this re-test, it produced numbers that were only a few percent different from its original posted value of 115,612 psi, which put that oil in the OUTSTANDING PROTECTION category (Over 90,000 psi). So, the test equipment and procedure are still right on the money. Therefore, these Diesel oil psi numbers are absolutely correct, and simply are what they are. So, what’s going on here?
Obviously since all these diesel oil numbers are so closely clustered together with only about a 20,000 psi range (compared to the gas engine oil numbers which have a much larger range of almost 60,000 psi), it is clear that the oil companies intentionally formulated them to be in this general range. Why would they do that? How can that be good enough for these hard working diesel engines?
Diesel engines of this type are made very rugged and very durable for the long haul. And in order to accomplish that, the engine’s components are designed and sized to keep the part loading at a modest level. And of course, these engines are known primarily for their impressive low end torque under boost, but NOT for their high rpm HP. All that being the case, these oils don’t need to have a higher capability. And this type of Diesel engine typically takes a LOT OF OIL. So, cost becomes a real factor when changing oil. This means that no oil company is going to make their products way better than needed, because that would make their products too expensive to be competitive in the marketplace.
And no one can complain that my test equipment and test procedure do not allow high zinc oils to perform at their highest level. Because here are some high zinc (over 1100 ppm) conventional, semi-synthetic, and full synthetic gasoline engine oils that I’ve tested previously. And they all had test results over 90,000 psi, which put them in the “OUTSTANDING PROTECTION” category for gasoline engines.
The average value for Thermal Breakdown among the synthetic Diesel oils here, was 267*, which is 15* LOWER than among the synthetic gas engine oils I've tested.
And as you can see with these Diesel oils above, zinc levels alone do NOT establish their wear prevention ranking. The zinc levels are randomly up and down, relative to the ranking order. And as you will see in the complete 61 motor oil ranking list below, zinc levels clearly have NOTHING to do with an oil's protection capability or ranking order. Also, anyone who has followed my motor oil testing this year, probably noticed that these Diesel oil “Load Carrying Capacity/Film Strength” psi values are rather low, with an average value for the whole group of only 72,408 psi. This number would put an oil for gasoline engines, only in the MODEST PROTECTION category (60,000 to 75,000 psi). And individually, Red Line, the top ranked Diesel oil, ranks only 33rd out of 61 oils I’ve tested so far. The Red Line and Royal Purple, are the only Diesel oils to even make it into the GOOD PROTECTION category (75,000 to 90,000 psi) for use in gasoline engines. Overall that’s not very impressive to say the least, when you consider how wonderful many people “thought” Diesel oil was.
And considering that these oils are intended for use in heavy duty working Diesel engines as used in big rigs, bulldozers, locomotives, etc, etc, you probably expected to see some rather impressive psi numbers. But, if you were expecting that, you were obviously disappointed and maybe even shocked.
The oil testing equipment and the test procedure used here, were working perfectly fine, with no issue at all. In fact, in the middle of testing all these Diesel oils, I performed what you might call a calibration check, by re-testing once again, the number one ranked gas engine oil, the 5W30 Pennzoil Ultra, API SM, to see if its numbers would be reproduced within the normal variation range. And in this re-test, it produced numbers that were only a few percent different from its original posted value of 115,612 psi, which put that oil in the OUTSTANDING PROTECTION category (Over 90,000 psi). So, the test equipment and procedure are still right on the money. Therefore, these Diesel oil psi numbers are absolutely correct, and simply are what they are. So, what’s going on here?
Obviously since all these diesel oil numbers are so closely clustered together with only about a 20,000 psi range (compared to the gas engine oil numbers which have a much larger range of almost 60,000 psi), it is clear that the oil companies intentionally formulated them to be in this general range. Why would they do that? How can that be good enough for these hard working diesel engines?
Diesel engines of this type are made very rugged and very durable for the long haul. And in order to accomplish that, the engine’s components are designed and sized to keep the part loading at a modest level. And of course, these engines are known primarily for their impressive low end torque under boost, but NOT for their high rpm HP. All that being the case, these oils don’t need to have a higher capability. And this type of Diesel engine typically takes a LOT OF OIL. So, cost becomes a real factor when changing oil. This means that no oil company is going to make their products way better than needed, because that would make their products too expensive to be competitive in the marketplace.
And no one can complain that my test equipment and test procedure do not allow high zinc oils to perform at their highest level. Because here are some high zinc (over 1100 ppm) conventional, semi-synthetic, and full synthetic gasoline engine oils that I’ve tested previously. And they all had test results over 90,000 psi, which put them in the “OUTSTANDING PROTECTION” category for gasoline engines.
