Motor Oils: Synthetic Vs Conventional

With more and more new vehicles going with lower viscosity oils such as 0-20 or 5-20 for greater fuel savings, either a synthetic oil is specified or a conventional may be used, if stipulated in the owner's manual. For example, my 2014 Forester uses 0-20 synthetic oil with the factory fill to be changed initially at 3000 miles and 7500 thereafter. The scuttlebutt on the web states the factory fill Idemitsu(Japanese manufactured oil) has high levels of molybdenum, zinc and phosphorous which are friction modifiers for the break-in period so everything in the engine seats as it should without wear. My first two years of oil changes are gratis at the dealer and reportedly use Idemitsu synthetic 0-20 oil but without the same levels of the friction modifiers used in the factory fill oil. My choice thereafter will probably be mag1 0-20 synthetic oil, manufactured by Warren oil company, one of the oldest and most established oil companies in America. While I believe any of the oils meeting the latest SN specs would probably suffice, Warren does post its ingredients while other companies reportedly do not:
http://www.mag1.com/Products.aspx?id=bb59b3e3-741c-44a2-9b27-d24fab3f7773
It's also among the least expensive synthetics coming in at just under 30 bucks for a case of six quart bottles in Amazon. I bought some recently. Other synthetics appear to be running about the same for a 4 or 5 quart jug at Walmart.
I'm not sure that synthetics really offer greater protection than conventional oils. Several years ago, Consumer Reports tested a variety of synthetic and conventional motor oils in heavy duty use in New York taxis and, after tearing the engines apart, couldn't find any meaningful differences in wear or deposits from any of the oils they tested. The only difference they did find was in the pour-point in extremely cold sub-zero weather wherein one synthetic oil, Mobil One, flowed much better than the other oils tested. It's interesting to note that the pour point of Mag1 oil is the same as Mobil One. But it appears that unless you're driving in extremely cold weather, way below zero, you're unlikely to see differences in engine wear. I understand you've got to follow the owner's manual for warranty coverage so that's the final word on the matter. Still, I wonder if the high priced synthetics really live up to the hype...

When I was a Master Tech for BMW we did not use synthetic oils. During the years from 1975-1995 we used 20/50 Valvoline Racing oil as our standard oil. I worked on some cars for many years and those that changed their oil every 3,500 miles had no wear that I could measure on cams and other upper components that I was able to check easily. The engines were completely clean with old a light golden color to the aluminum alloys. I serviced engines with 150,000+ miles that looked just like this.

I have nothing against synthetic oils though. They do have some good characteristics under brutal conditions like racing. They resisted the effects of extreme heat with low oil pressure better than standard oils.

However, like many other additives that were tested, they normally only showed their better qualities under conditions that would not be considered normal driving conditions.

With the increased cost of oil in general, the cost difference between the two types is of no real consequence. It is a minor expense over the life of a cars engine. So if your dealer uses a particular synthetic oil and the cost of an oil change is similar to buying and oil and filter, then it might be easier to let them change it. Then any long warranties they have provided will always be no problem when you need to obtain repairs. Plus it can give you an edge if you are a good customer should a repair under "Good Will" be contemplated.

Most engines are so clean burning today that 7,500 miles between changes has become pretty typical. Some people still change their oil at 3,000-3,500 miles and though it may not be necessary, it is still a minor expense over the life of the car.

Dude. You're driving a Subaru. An economy car. Come down to earth.

My Prius is supposed to get 0-20 semi synthetic, though we switched to fully synthetic. Factory recommended intervals are every 10K since the gas engine does not see the same duty cycles as a traditional car.

Synthetics offer better friction protection, helpful for both gas mileage and longevity.

Hoping to get 400,000 miles out of this car, given that I have put 15,000 on it in just 4 months, that wont be to far out.

It has Mobil 1 and Castrol 0-20 testing well.

I really don't think that you need to overthink this oil choice issue for a low-performance, low-stress econo car and $100/year worth of oil. Just use decent oil and change it. If you have a high-revving air-cooled Porsche or a 1968 flat-tappet muscle car it's a different story. But there are some pretty bad oils out there that are mostly hype and there are useless additives that are an entire waste of money except for marketing.

Here is another POV from an SAE engineer that does his own shear testing:


I have done extensive motor oil “Wear Testing” over the past year or so, to see how nearly a hundred different motor oils compare regarding their wear protection capability. Because I wanted to cut through all the misinformation that is out there about motor oil, and get to the truth and find out what the FACTS really are. The resulting oil test data is NOT a theory. It is NOT an opinion. It is the real deal, because it is REAL WORLD TEST DATA, just like engine dyno output data is real world test data.

Oil film strength testing is the ONLY way to determine an oil’s wear protection capability, because oil film strength is the last line of defense against metal to metal contact and subsequent wear or damage. In order to reach metal to metal contact, you MUST penetrate the film strength of the oil. And oil thicker than a mere film becomes liquid oil. Of course liquids are NOT compressible, which is how hydraulics work. Since liquids cannot be compressed, ALL oils provide THE SAME wear protection when they are in liquid form, no matter if they cost $1.00 per quart or $20.00 per quart. So, since the determining factor between wear and no wear, is an oil’s film strength capability, that makes oil film strength testing the GOLD STANDARD for determining how capable an oil is at preventing wear, and how different oils directly compare to each other.

Oil film strength capability DIRECTLY APPLIES to flat tappet lobe/lifter interfaces, cam gear/distributor gear interfaces, mechanical fuel pump pushrod tip/cam eccentric interfaces and other highly loaded engine component interfaces.

For those folks who are interested in this real world test data, posted below is the “Load Carrying Capacity/Film Strength” ranking list from all the real world motor oil “Wear Testing” (dynamic friction testing under load) that I’ve performed so far on new oils, at a representative operational temperature of 230*F. The list includes modern API certified low zinc oils, traditional high zinc High Performance/Racing oils, Diesel oils, low zinc oils with zinc additives added in, and Break-In oils. Lower ranked oils are not necessarily “bad”, they simply don’t provide as much reserve wear protection capability as higher ranked oils. Everyone can decide for themselves, how much reserve wear protection capability they are comfortable with for any given engine build. The higher the psi value, the BETTER wear protection.


The higher the psi value, the BETTER wear protection.


Oil categories for gasoline engines:

• Over 90,000 psi = OUTSTANDING wear protection

• 75,000 to 90,000 psi = GOOD wear protection

• 60,000 to 75,000 psi = MODEST wear protection

• Below 60,000 psi = UNDESIRABLE wear protection




1. 5W30 Pennzoil Ultra, API SM synthetic = 115,612 psi
I have not been able to find this oil with the latest API SN certification. The bottle says, “No leading synthetic oil provides better wear protection”. For once, a product’s hype turns out to be true.
zinc = 806 ppm
phos = 812 ppm
moly = 66 ppm

2. 10W30 Lucas Racing Only synthetic = 106,505 psi
zinc = 2642 ppm
phos = 3489 ppm
moly = 1764 ppm
NOTE: This oil is suitable for short term racing use only, and is not suitable for street use.

3. 5W30 Mobil 1, API SN synthetic = 105,875 psi
zinc = 801 ppm
phos = 842 ppm
moly = 112 ppm

4. 0W30 Amsoil Signature Series 25,000 miles, API SN synthetic = 105,008 psi
zinc = 824 ppm
phos = 960 ppm
moly = 161 ppm


5. 10W30 Valvoline NSL (Not Street Legal) Conventional Racing Oil = 103,846 psi
zinc = 1669 ppm
phos = 1518 ppm
moly = 784 ppm
NOTE: This oil is suitable for short term racing use only, and is not suitable for street use.

6. 5W50 Motorcraft, API SN synthetic = 103,517 psi
zinc = 606 ppm
phos = 742 ppm
moly = 28 ppm

7. 10W30 Valvoline VR1 Conventional Racing Oil (silver bottle) = 103,505 psi
zinc = 1472 ppm
phos = 1544 ppm
moly = 3 ppm

8. 10W30 Valvoline VR1 Synthetic Racing Oil, API SL (black bottle) = 101,139 psi
zinc = 1180 ppm
phos = 1112 ppm
moly = 162 ppm

9. 5W30 Chevron Supreme, API SN conventional = 100,011 psi
This oil only cost $4.29 per quart at an Auto Parts Store when I bought it.
zinc = 1018 ppm
phos = 728 ppm
moly = 161 ppm

10. 5W20 Castrol Edge with Titanium, API SN synthetic = 99,983 psi
zinc = 1042 ppm
phos = 857 ppm
moly = 100 ppm
titanium = 49 ppm

11. 20W50 Castrol GTX ,API SN conventional = 96,514 psi
zinc = 610 ppm
phos = 754 ppm
moly = 94 ppm

12. 30 wt Red Line Race Oil synthetic = 96,470 psi
zinc = 2207 ppm
phos = 2052 ppm
moly = 1235 ppm
NOTE: This oil is suitable for short term racing use only, and is not suitable for street use.

13. 0W20 Mobil 1 Advanced Fuel Economy, API SN synthetic = 96,364 psi
zinc = 742 ppm
phos = 677 ppm
moly = 81 ppm

14. 5W30 Quaker State Ultimate Durability, API SN synthetic = 95,920 psi
zinc = 877 ppm
phos = 921 ppm
moly = 72 ppm

15. 5W30 Castrol Edge with Titanium, API SN synthetic = 95,717 psi
zinc = 818 ppm
phos = 883 ppm
moly = 90 ppm
titanium = 44 ppm

16. 10W30 Joe Gibbs XP3 NASCAR Racing Oil synthetic = 95,543 psi
zinc = 743 ppm
phos = 802 ppm
moly = 1125 ppm
NOTE: This oil is suitable for short term racing use only, and is not suitable for street use.

17. 5W20 Castrol GTX, API SN conventional = 95,543 psi
zinc = TBD
phos = TBD
moly = TBD
NOTE: Oil numbers 16 and 17 were tested weeks apart, but due to the similarities in their wear scar sizes, their averages ended up the same.

18. 5W30 Castrol GTX ,API SN conventional = 95,392 psi
zinc = 830 ppm
phos = 791 ppm
moly = 1 ppm

19. 10W30 Amsoil Z-Rod Oil synthetic = 95,360 psi
zinc = 1431 ppm
phos = 1441 ppm
moly = 52 ppm

20. 5W30 Valvoline SynPower, API SN synthetic = 94,942 psi
zinc = 969 ppm
phos = 761 ppm
moly = 0 ppm

21. 5W30 Valvoline Premium Conventional, API SN = 94,744 psi
zinc = TBD
phos = TBD
moly = TBD

22. 5W20 Mobil 1, API SN synthetic = 94,663 psi
zinc = 764 ppm
phos = 698 ppm
moly = 76 ppm

23. 5W20 Valvoline SynPower, API SN synthetic = 94,460 psi
zinc = 1045 ppm
phos = 742 ppm
moly = 0 ppm

24. 5W30 Lucas, API SN conventional = 92,073 psi
zinc = 992 ppm
phos = 760 ppm
moly = 0 ppm

25. 5W30 O'Reilly (house brand), API SN conventional = 91,433 psi
This oil only cost $3.99 per quart at an Auto Parts Store when I bought it.
zinc = 863 ppm
phos = 816 ppm
moly = 0 ppm

26. 5W30 Maxima RS530 Synthetic Racing Oil = 91,162 psi
zinc = 2162 ppm
phos = 2294 ppm
moly = 181 ppm

27. 5W30 Red Line, API SN synthetic = 91,028 psi
zinc = TBD
phos = TBD
moly = TBD

28. 5W20 Royal Purple API SN synthetic = 90,434 psi
zinc = 964 ppm
phos = 892 ppm
moly = 0 ppm

29. 10W30 Quaker State Defy, API SL semi-synthetic = 90,226 psi
zinc = 1221 ppm
phos = 955 ppm
moly = 99 ppm

30. 10W60 Castrol TWS Motorsport, API SJ conventional = 90,163 psi
This oil is manufactured in Europe and is sold in the US for BMW models M3, M5, M6, Z4M, and Z8.
zinc = TBD
phos = TBD
moly = TBD

31. 5W20 Valvoline Premium Conventional, API SN = 90,144 psi
zinc = TBD
phos = TBD
moly = TBD

32. 30 wt Castrol Heavy Duty, API SM conventional = 88,089 psi
zinc = 907 ppm
phos = 829 ppm
moly = 56 ppm

33. 20W50 LAT Synthetic Racing Oil, API SM = 87,930 psi
zinc = TBD
phos = TBD
moly = TBD

34. 10W30 Joe Gibbs HR4 Hotrod Oil synthetic = 86,270 psi
zinc = 1247 ppm
phos = 1137 ppm
moly = 24 ppm

35. 5W20 Pennzoil Ultra, API SM synthetic = 86,034 psi
I have not been able to find this oil with the latest API SN certification.
zinc = TBD
phos = TBD
moly = TBD

36. 15W40 RED LINE Diesel Oil synthetic, API CJ-4/CI-4 PLUS/CI-4/CF/CH-4/CF-4/SM/SL/SH/EO-O = 85,663 psi
zinc = 1615 ppm
phos = 1551 ppm
moly = 173 ppm

37. 5W30 Royal Purple API SN synthetic = 84,009 psi
zinc = 942 ppm
phos = 817 ppm
moly = 0 ppm

38. 20W50 Royal Purple API SN synthetic = 83,487 psi
zinc = 588 ppm
phos = 697 ppm
moly = 0 ppm

39. 20W50 Kendall GT-1 High Performance with liquid titanium, API SN conventional = 83,365 psi
zinc = 991 ppm
phos = 1253 ppm
moly = 57 ppm
titanium = 84 ppm

40. 5W30 Mobil 1 Extended Performance 15,000 mile, API SN synthetic = 83,263 psi
zinc = 890 ppm
phos = 819 ppm
moly = 104 ppm

41. 0W20 Castrol Edge with Titanium, API SN synthetic = 82,867 psi
zinc = TBD
phos = TBD
moly = TBD

42. 5W30 LAT Synthetic Racing Oil, API SM = 81,800 psi
zinc = 1784 ppm
phos = 1539 ppm
moly = 598 ppm

43. 15W40 ROYAL PURPLE Diesel Oil synthetic, API CJ-4 /SM, CI-4 PLUS, CH-4, CI-4 = 76,997 psi
zinc = TBD
phos = TBD
moly = TBD

44. 5W30 Lucas API SM synthetic = 76,584 psi
zinc = 1134 ppm
phos = 666 ppm
moly = 0 ppm

45. 5W30 GM's AC Delco dexos 1 API SN semi-synthetic = 76,501 psi
zinc = 878 ppm
phos = 758 ppm
moly = 72 ppm

46. 5W50 Castrol Edge with Syntec API SN, synthetic, formerly Castrol Syntec, black bottle = 75,409 psi
zinc = 1252 ppm
phos = 1197 ppm
moly = 71 ppm

47. 5W30 Royal Purple XPR (Extreme Performance Racing) synthetic = 74,860 psi
zinc = 1421 ppm
phos = 1338 ppm
moly = 204 ppm
NOTE: This particular bottle of oil was just opened, but was out of a 3 ½ year old case.

48. 5W40 MOBIL 1 TURBO DIESEL TRUCK synthetic, API CJ-4, CI-4 Plus, CI-4, CH-4 and ACEA E7 = 74,312 psi
zinc = 1211 ppm
phos = 1168 ppm
moly = 2 ppm

49. 15W40 CHEVRON DELO 400LE Diesel Oil, conventional, API CJ-4, CI-4 Plus, CH-4, CF-4,CF/SM, = 73,520 psi
zinc = 1519 ppm
phos = 1139 ppm
moly = 80 ppm

50. 15W40 MOBIL DELVAC 1300 SUPER Diesel Oil conventional, API CJ-4, CI-4 Plus, CI-4, CH-4/SM, SL = 73,300 psi
zinc = 1297 ppm
phos = 1944 ppm
moly = 46 ppm

51. 15W40 Farm Rated Heavy Duty Performance Diesel Oil conventional CI-4, CH-4, CG-4, CF/SL, SJ = 73,176 psi
zinc = 1325ppm
phos = 1234 ppm
moly = 2 ppm

52. 15W40 SHELL ROTELLA T Diesel Oil conventional, API CJ-4, CI-4 Plus, CH-4, CF-4,CF/SM = 72,022 psi
zinc = 1454 ppm
phos = 1062 ppm
moly = 0 ppm

53. Brad Penn, Penn Grade 1 Nitro 70 Racing Oil semi-synthetic = 72,003 psi
zinc = TBD
phos = TBD
moly = TBD

54. 0W30 Brad Penn, Penn Grade 1 semi-synthetic = 71,377 psi
zinc = 1621 ppm
phos = 1437 ppm
moly = 0 ppm

55. 15W40 “OLD” SHELL ROTELLA T Diesel Oil conventional, API CI-4 PLUS, CI-4, CH-4,CG-4,CF-4,CF,SL, SJ, SH = 71,214 psi
zinc = 1171 ppm
phos = 1186 ppm
moly = 0 ppm

56. 10W30 Brad Penn, Penn Grade 1 semi-synthetic = 71,206 psi
zinc = 1557 ppm
phos = 1651 ppm
moly = 3 ppm

57. 15W40 VALVOLINE PREMIUM BLUE HEAVY DUTY DIESEL Oil conventional, API CJ-4, CI-4 Plus, CI-4, CH-4, CG-4, CF-4, CF/SM = 70,869 psi
zinc = TBD
phos = TBD
moly = TBD

58. 15W50 Mobil 1, API SN synthetic = 70,235 psi
zinc = 1,133 ppm
phos = 1,168 ppm
moly = 83 ppm

59. 5W40 CHEVRON DELO 400LE Diesel Oil synthetic, API CJ-4, CI-4 Plus, CI-4, SL, SM = 69,631 psi
zinc = TBD
phos = TBD
moly = TBD

60. 30wt Edelbrock Break-In Oil conventional = 69,160 psi
zinc = 1545 ppm
phos = 1465 ppm
moly = 4 ppm

61. 5W30 Motorcraft, API SN synthetic = 68,782 psi
zinc = 796 ppm
phos = 830 ppm
moly = 75 ppm

62. 10W40 Edelbrock synthetic = 68,603 psi
zinc = 1193 ppm
phos = 1146 ppm
moly = 121 ppm
This oil is manufactured for Edelbrock by Torco.


63. 5W40 SHELL ROTELLA T6 Diesel Oil synthetic, API CJ-4, CI-4 Plus, CI-4, CH-4, SM, SL = 67,804 psi
zinc = TBD
phos = TBD
moly = TBD

64. 15W40 LUCAS MAGNUM Diesel Oil, conventional, API CI-4,CH-4, CG-4, CF-4, CF/SL = 66,476 psi
zinc = 1441 ppm
phos = 1234 ppm
moly = 76 ppm

65. 15W40 CASTROL GTX DIESEL Oil conventional, API CJ-4, CI-4 Plus, CI-4, CH-4, CG-4, CF-4/SN = 66,323 psi
zinc = TBD
phos = TBD
moly = TBD

66. 10W30 Royal Purple HPS (High Performance Street) synthetic = 66,211 psi
zinc = 1774 ppm
phos = 1347 ppm
moly = 189 ppm

67. 10W40 Valvoline 4 Stroke Motorcycle Oil, API SJ conventional = 65,553 psi
zinc = 1154 ppm
phos = 1075 ppm
moly = 0 ppm

68. 5W30 Klotz Estorlin Racing Oil, API SL synthetic = 64,175 psi
zinc = 1765 ppm
phos = 2468 ppm
moly = 339 ppm

69. “ZDDPlus” added to Royal Purple 20W50, API SN, synthetic = 63,595 psi
zinc = 2436 ppm (up 1848 ppm)
phos = 2053 ppm (up 1356 ppm)
moly = 2 ppm (up 2 ppm)

The amount of ZDDPlus added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 24% LOWER than this oil had BEFORE the ZDDPlus was added to it. Most major Oil Companies say to NEVER add anything to their oils, because adding anything will upset the carefully balanced additive package, and ruin the oil’s chemical composition. And that is precisely what we see here. Adding ZDDPlus SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

70. Royal Purple 10W30 Break-In Oil conventional = 62,931 psi
zinc = 1170 ppm
phos = 1039 ppm
moly = 0 ppm

71. 10W30 Lucas Hot Rod & Classic Hi-Performance Oil, conventional = 62,538 psi
zinc = 2116 ppm
phos = 1855 ppm
moly = 871 ppm

72. 0W20 Klotz Estorlin Racing Oil, API SL synthetic = 60,941 psi
zinc = TBD
phos = TBD
moly = TBD

73. 10W30 Comp Cams Muscle Car & Street Rod Oil, synthetic blend = 60,413 psi
zinc = 1673 ppm
phos = 1114 ppm
moly = 67 ppm
This oil is manufactured for Comp Cams by Endure.

74. 10W40 Torco TR-1 Racing Oil with MPZ conventional = 59,905 psi
zinc = 1456 ppm
phos = 1150 ppm
moly = 227 ppm

75. Summit Racing 10W40 Premium Racing Oil, API SL = 59,483 psi
zinc = TBD
phos = TBD
moly = TBD

76. 10W40 Edelbrock conventional = 59,120 psi
zinc = TBD
phos = TBD
moly = TBD
This oil is manufactured for Edelbrock by Torco.

77. 0W20 LAT Synthetic Racing Oil, API SM = 57,228 psi
zinc = TBD
phos = TBD
moly = TBD


78. “ZDDPlus” added to O’Reilly (house brand) 5W30, API SN, conventional = 56,728 psi
zinc = 2711 ppm (up 1848 ppm)
phos = 2172 ppm (up 1356 ppm)
moly = 2 ppm (up 2 ppm)

The amount of ZDDPlus added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 38% LOWER than this oil had BEFORE the ZDDPlus was added to it. Adding ZDDPlus SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.


79. “ZDDPlus” added to Motorcraft 5W30, API SN, synthetic = 56,243 psi
zinc = 2955 ppm (up 1848 ppm)
phos = 2114 ppm (up 1356 ppm)
moly = 76 ppm (up 2 ppm)

The amount of ZDDPlus added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 12% LOWER than this oil had BEFORE the ZDDPlus was added to it. Adding ZDDPlus SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

80. “Edelbrock Zinc Additive” added to Royal Purple 5W30, API SN, synthetic = 54,044 psi
zinc = 1515 ppm (up 573 ppm)
phos = 1334 ppm (up 517 ppm)
moly = 15 ppm (up 15 ppm)

The amount of Edelbrock Zinc Additive added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was a whopping 36% LOWER than this oil had BEFORE the Edelbrock Zinc Additive was added to it. Adding Edelbrock Zinc Additive SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

81. 10W30 Comp Cams Break-In Oil conventional = 51,749 psi
zinc = 3004 ppm
phos = 2613 ppm
moly = 180 ppm

82. “Edelbrock Zinc Additive” added to Lucas 5W30, API SN, conventional = 51,545 psi
zinc = 1565 ppm (up 573 ppm)
phos = 1277 ppm (up 517 ppm)
moly = 15 ppm (up 15 ppm)

The amount of Edelbrock Zinc Additive added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was a “breath taking” 44% LOWER than this oil had BEFORE the Edelbrock Zinc Additive was added to it. Adding Edelbrock Zinc Additive SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

83. “Edelbrock Zinc Additive” added to Motorcraft 5W30, API SN, synthetic = 50,202 psi
zinc = 1680 ppm (up 573 ppm)
phos = 1275 ppm (up 517 ppm)
moly = 89 ppm (up 15 ppm)

The amount of Edelbrock Zinc Additive added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 22% LOWER than this oil had BEFORE the Edelbrock Zinc Additive was added to it. Adding Edelbrock Zinc Additive SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

84. 30wt Lucas Break-In Oil conventional = 49,455 psi
zinc = 4483 ppm
phos = 3660 ppm
moly = 3 ppm

540 RAT
Member SAE (Society of Automotive Engineers)
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#32
Old Apr 29th, 13, 3:35 PM
540 RAT 540 RAT is offline
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Default Re: Motor oil ?
And regarding viscosity:


Consider THE BENEFITS OF USING THINNER OIL:

• Thinner oil flows quicker at cold start-up to begin lubricating critical engine components much more quickly than thicker oil can. Most engine wear takes place during cold start-up before oil flow can reach all the components. So, quicker flowing thinner oil will help reduce start-up engine wear, which is actually reducing wear overall.

• Thinner oil also flows more at normal operating temperatures. And oil FLOW is lubrication, but oil pressure is NOT lubrication. Oil pressure is only a measurement of resistance to flow. Running thicker oil just to up the oil pressure is the wrong thing to do, because that only reduces oil flow/lubrication. Oil pressure in and of itself, is NOT what we are after.

• The old rule of thumb that we should have at least 10 psi for every 1,000 rpm is perfectly fine. Running thicker oil to achieve more pressure than that, will simply reduce oil flow for no good reason. It is best to run the thinnest oil we can, that will still maintain at least the rule of thumb oil pressure. And one of the benefits of running a high volume oil pump, is that it will allow us to enjoy all the benefits of running thinner oil, while still maintaining enough oil pressure. A high volume oil pump/thinner oil combo is preferred over running a standard volume oil pump/thicker oil combo. Because oil “flow” is our goal for ideal oiling, NOT simply high oil pressure.

• Oil flow is what carries heat away from internal engine components. Those engine components are DIRECTLY oil cooled, but only INdirectly water cooled. And better flowing thinner oil will keep critical engine components cooler because it carries heat away faster. If you run thicker oil than needed, you will be driving up engine component temps.

• Thinner oil will typically increase HP because of less viscous drag and reduced pumping losses, compared to thicker oils. That is why very serious Race efforts will generally use watery thin oils in their engines. But, an exception to this increase in HP would be in high rpm hydraulic lifter engines, where thinner oil can allow the lifters to bleed-off at higher rpm. In everyday street vehicles, where fuel consumption is a consideration, thinner oils will also typically increase fuel economy. The majority of new cars sold in the U.S. now call for 5W20 specifically for increased fuel economy. And now Diesel trucks are increasingly calling for 5W30, also for fuel economy improvement.

• With the exception of high rpm hydraulic lifter engines, almost no engine should ever need to run oil thicker than a multi-viscosity 30 weight. The lower the first number cold viscosity rating, the better the cold flow. For example, 0W30 flows WAY better cold than 20W50. And 0W30 flows WAY better cold than straight 30wt, which is horrible for cold start-up flow and should be avoided at all cost. And the lower the second number hot viscosity rating, the better the hot flow. For example, 0W30 flows WAY better hot than 20W50.

• Thicker oil DOES NOT automatically provide better wear protection than thinner oils. Extensive “dynamic wear testing under load” of dozens and dozens of motor oils, has shown that the base oil and its additive package “as a whole”, is what determines an oil’s wear protection capability, NOT its viscosity. For example, some 5W20 oils have proven to provide OUTSTANDING wear protection, while some 15W50 oils have only been able to provide MODEST wear protection. So, do not run thicker oil under the false assumption that it can provide better wear protection for our engines.

• BOTTOM LINE: Thinner oils are better for most engine lubrication needs.

540 RAT
Member SAE (Society of Automotive Engineers)