Oil Labelling Explained - Revision history

paulc: /* Are 5w and 0w oils too thin? */

2008-01-23T14:29:30Z

Are 5w and 0w oils too thin?

@@ Line 262: / Line 262: @@
 SAE 40 (straight 40)
-Temp degC.........................Viscosity (thickness)
+{| border="1"
 As you will see, there is plenty of viscosity at 0degC, in fact many times more than at 100degC and this is the problem especially in cold weather, can the oil flow quick enough to protect vital engine parts at start up. Not really!
@@ Line 292: / Line 308: @@
 However, if you are seeing temperatures in excess of 120degC due to mods and track use etc then there is a strong argument to using an sae 50 as it will have more viscosity at these excessive temperatures.
 There are trade offs here. Thicker oils cause more friction and therefore more heat and they waste power and affect fuel consumption so it's always best to use the thinnest oil (i.e. second number) that you can get away with and still maintain oil pressure.
 ==Other sources of information==

hbaumhardt: /* Why oils lose viscosity with use */

2007-10-23T22:19:22Z

Why oils lose viscosity with use

← Older revision		Revision as of 22:19, 23 October 2007
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	A relatively new oil test/specification, the oil is subjected to high temperature 150C and is mechanically sheared at 1 x 10^6 per second. A value of 2.8 or is considered the minumum for normal bearing wear. Here are some HTHS numbers on well known oils, the higher the number the more shear stable the oil; 4's and 5's are excellent numbers and demonstrate basestock quality e.g. Silkolene and Motul.		A relatively new oil test/specification, the oil is subjected to high temperature 150C and is mechanically sheared at 1 x 10^6 per second. A value of 2.8 or is considered the minumum for normal bearing wear. Here are some HTHS numbers on well known oils, the higher the number the more shear stable the oil; 4's and 5's are excellent numbers and demonstrate basestock quality e.g. Silkolene and Motul.

	~~Castrol RS 10w-60~~ HTHS 3.70		Mobil 1 0W40 HTHS 3.6

	Castrol RS 0w-40 HTHS 3.70		Castrol RS 10w-60 HTHS 3.7

			Castrol RS 0w-40 HTHS 3.7

	Silkolene PRO S 5w-40 HTHS 4.07		Silkolene PRO S 5w-40 HTHS 4.07
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	Motul 300V 5w-40 HTHS 4.51		Motul 300V 5w-40 HTHS 4.51

	Mobil 1 ~~Motorsport~~ 15w-50 HTHS 5.11		Redline 5w40 HTHS 4.6

			Redline 10W40 HTHS 4.7

			Mobil 1 15w-50 HTHS 5.11

	Silkolene PRO S 10w-50 HTHS 5.11		Silkolene PRO S 10w-50 HTHS 5.11
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	Motul 300V 15w-50 HTHS 5.33		Motul 300V 15w-50 HTHS 5.33

			Redline 15W50 HTHS 5.8

Andrew S at 15:07, 14 June 2007

2007-06-14T15:07:41Z

← Older revision		Revision as of 15:07, 14 June 2007
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	TRACK: Change periods will be determined by quality of the oil i.e. how shear stable it is under track conditions. A decent race oil will take about 10 hours of hard track use and a semi-syntehtic or hydrocracked base stock will last about an hour before the oil begins to lose viscosity.		TRACK: Change periods will be determined by quality of the oil i.e. how shear stable it is under track conditions. A decent race oil will take about 10 hours of hard track use and a semi-syntehtic or hydrocracked base stock will last about an hour before the oil begins to lose viscosity.

			==Are 5w and 0w oils too thin?==

			I read on many forums about 0w and 5w oils being too thin.

			0w-40, 5w-40, 10w-40 and 15w-40 are all the same thickness (14 centistokes) at 100degC.

			Centistokes (cst) is the measure of a fluid's resistance to flow (viscosity). It is calculated in terms of the time required for a standard quantity of fluid at a certain temperature to flow through a standard orifice. The higher the value, the more viscous the fluid.

			As viscosity varies with temperature, the value is meaningless unless accompanied by the temperature at which it is measured. In the case of oils, viscosity is generally reported in centistokes (cst) and usually measured at 40degC and 100degC.

			So, all oils that end in 40 (sae 40) are around 14cst thickness at 100degC.

			This applies to all oils that end in the same number, all oils that end in 50 (sae 50) are around 18.5cst at 100degC and all oils that end in 60 (sae 60) are around 24cst at 100degC.

			With me so far?

			Great!

			Now, ALL oils are thicker when cold. Confused? It's true and here is a table to illustrate this.

			SAE 40 (straight 40)

			Temp degC.........................Viscosity (thickness)

			0..........................................2579cst
			20..........................................473cst
			40..........................................135cst
			60..........................................52.2cs t
			100........................................ 14cst
			120.........................................8.8cst

			As you will see, there is plenty of viscosity at 0degC, in fact many times more than at 100degC and this is the problem especially in cold weather, can the oil flow quick enough to protect vital engine parts at start up. Not really!

			So, given that an sae 40 is 14cst at 100degC which is adequate viscosity to protect the engine, and much thicker when cold, how can a 0w oil be too thin?

			Well, it can't is the truth.

			The clever part (thanks to synthetics) is that thin base oils can be used so that start up viscosity (on say a 5w-40 at 0degC) is reduced to around 800cst and this obviously gives much better flow than a monograde sae 40 (2579cst as quoted above).

			So, how does this happen, well as explained at the beginning, it's all about temperature, yes a thin base oil is still thicker when cold than at 100degC but the clever stuff (due to synthetics again) is that the chemists are able to build these oils out of molecules that do not thin to less than 14cst at 100degC!

			What are the parameters for our recommendations?
			Well, we always talk about good cold start protection, by this we mean flow so a 5w will flow better than a 10w and so on. This is why we recommend 5w or 10w as the thickest you want to use except in exceptional circumstances. Flow is critical to protect the engine from wear!

			We also talk about oil temps, mods and what the car is used for. This is related to the second number xw-(XX) as there may be issues with oil temperatures causing the oil to be too thin and therefore the possibility of metal to metal contact.

			This is difficult to explain but, if for example your oil temp does not exceed 120degC at any time then a good "shear stable" sae 40 is perfectly capable of giving protection.

			"Shear stability" is important here because if the oil shears it thins and that's not good!

			However, if you are seeing temperatures in excess of 120degC due to mods and track use etc then there is a strong argument to using an sae 50 as it will have more viscosity at these excessive temperatures.

			There are trade offs here. Thicker oils cause more friction and therefore more heat and they waste power and affect fuel consumption so it's always best to use the thinnest oil (i.e. second number) that you can get away with and still maintain oil pressure.


	==Other sources of information==		==Other sources of information==

Mr Wiki at 13:36, 17 April 2007

2007-04-17T13:36:53Z

← Older revision		Revision as of 13:36, 17 April 2007
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	[http://en.wikipedia.org/wiki/Motor_oil Wikipedia on Motor Oil]		[http://en.wikipedia.org/wiki/Motor_oil Wikipedia on Motor Oil]


			[[Category:Engine]]
			[[Category:Fluid]]
			[[Category:Lotus Elise]]
			[[Category:S1]]
			[[Category:S2]]

hbaumhardt: /* Why oils lose viscosity with use */

2006-11-08T22:51:51Z

Why oils lose viscosity with use

← Older revision		Revision as of 22:51, 8 November 2006
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	Most semi synthetics are past their best between 3-5000 miles, synthetics are good for 9000-12000 miles on the road. ~~For~~ track a decent ~~synthetic~~ race oil will ~~last~~ 10 track ~~hours (so long as there is not excessive fuel dilution)~~.		ROAD: Most semi synthetics are past their best between 3-5000 miles, synthetics are good for 9000-12000 miles on the road.

			TRACK: Change periods will be determined by quality of the oil i.e. how shear stable it is under track conditions. A decent race oil will take about 10 hours of hard track use and a semi-syntehtic or hydrocracked base stock will last about an hour before the oil begins to lose viscosity.

	==Other sources of information==		==Other sources of information==

hbaumhardt: /* Why oils lose viscosity with use */

2006-08-23T20:21:36Z

Why oils lose viscosity with use

← Older revision		Revision as of 20:21, 23 August 2006
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	A relatively new oil test/specification, the oil is subjected to high temperature 150C and is mechanically sheared at 1 x 10^6 per second. A value of 2.8 or is considered the minumum for normal bearing wear. Here are some HTHS numbers on well known oils, the higher the number the more shear stable the oil; 4's and 5's are excellent numbers and demonstrate basestock quality e.g. Silkolene and Motul.		A relatively new oil test/specification, the oil is subjected to high temperature 150C and is mechanically sheared at 1 x 10^6 per second. A value of 2.8 or is considered the minumum for normal bearing wear. Here are some HTHS numbers on well known oils, the higher the number the more shear stable the oil; 4's and 5's are excellent numbers and demonstrate basestock quality e.g. Silkolene and Motul.

	Castrol RS 10w-60 HTHS 3.70		Castrol RS 10w-60 HTHS 3.70

	Castrol RS 0w-40 HTHS 3.70		Castrol RS 0w-40 HTHS 3.70

	Silkolene PRO S 5w-40 HTHS 4.07		Silkolene PRO S 5w-40 HTHS 4.07

	Motul 300V 10w-40 HTHS 4.19		Motul 300V 10w-40 HTHS 4.19

	Motul 300V 5w-40 HTHS 4.51		Motul 300V 5w-40 HTHS 4.51

	Mobil 1 Motorsport 15w-50 HTHS 5.11		Mobil 1 Motorsport 15w-50 HTHS 5.11

	Silkolene PRO S 10w-50 HTHS 5.11		Silkolene PRO S 10w-50 HTHS 5.11

	Silkolene PRO R 15w-50 HTHS 5.23		Silkolene PRO R 15w-50 HTHS 5.23

	Motul 300V 15w-50 HTHS 5.33		Motul 300V 15w-50 HTHS 5.33

hbaumhardt: /* Why oils lose viscosity with use */

2006-08-23T20:20:27Z

Why oils lose viscosity with use

← Older revision		Revision as of 20:20, 23 August 2006
Line 186:		Line 186:

	'''"Shearing"'''		'''"Shearing"'''

	The long chain molecules in VI Improvers are prone to "shearing" with use which reduces their ability to prevent the oil from losing viscosity. This "shearing" occurs when shear stress ruptures the long chain molecules and converts them to shorter, lower weight molecules. The shorter, lower weight molecules offer less resistance to flow and their ability to maintain viscosity is reduced.		The long chain molecules in VI Improvers are prone to "shearing" with use which reduces their ability to prevent the oil from losing viscosity. This "shearing" occurs when shear stress ruptures the long chain molecules and converts them to shorter, lower weight molecules. The shorter, lower weight molecules offer less resistance to flow and their ability to maintain viscosity is reduced.

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	'''Which oils require more VI Improvers?'''		'''Which oils require more VI Improvers?'''

	There are two scenarios where large amounts of these polymers are required as a rule.		There are two scenarios where large amounts of these polymers are required as a rule.

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	'''HTHS - High temperature High shear'''		'''HTHS - High temperature High shear'''

	A relatively new oil test/specification, the oil is subjected to high temperature 150C and is mechanically sheared at 1 x 10^6 per second. A value of 2.8 or is considered the minumum for normal bearing wear. Here are some HTHS numbers on well known oils, the higher the number the more shear stable the oil; 4's and 5's are excellent numbers and demonstrate basestock quality e.g. Silkolene and Motul.		A relatively new oil test/specification, the oil is subjected to high temperature 150C and is mechanically sheared at 1 x 10^6 per second. A value of 2.8 or is considered the minumum for normal bearing wear. Here are some HTHS numbers on well known oils, the higher the number the more shear stable the oil; 4's and 5's are excellent numbers and demonstrate basestock quality e.g. Silkolene and Motul.

hbaumhardt at 20:19, 23 August 2006

2006-08-23T20:19:49Z

← Older revision		Revision as of 20:19, 23 August 2006
Line 174:		Line 174:

	Like everything in life, you get what you pay for and the cheaper the oil the cheaper the ingredients and lower the performance levels.		Like everything in life, you get what you pay for and the cheaper the oil the cheaper the ingredients and lower the performance levels.



	==Why oils lose viscosity with use==		==Why oils lose viscosity with use==

hbaumhardt: /* Why oils lose viscosity with use */

2006-08-23T20:19:26Z

Why oils lose viscosity with use

← Older revision		Revision as of 20:19, 23 August 2006
Line 181:		Line 181:

	VI Improvers are heat sensitive long chain, high molecular weight polymers that minimise the viscosity loss of the oil at high temperatures. They work like springs, coiled at low temperatures and uncoiling at high temperatures. This makes the molecules larger (at high temps) which increases internal resistance within the thinning oil. They in effect "fight back" against the viscosity loss in the oil.		VI Improvers are heat sensitive long chain, high molecular weight polymers that minimise the viscosity loss of the oil at high temperatures. They work like springs, coiled at low temperatures and uncoiling at high temperatures. This makes the molecules larger (at high temps) which increases internal resistance within the thinning oil. They in effect "fight back" against the viscosity loss in the oil.


	'''"Shearing"'''		'''"Shearing"'''

	The long chain molecules in VI Improvers are prone to "shearing" with use which reduces their ability to prevent the oil from losing viscosity. This "shearing" occurs when shear stress ruptures the long chain molecules and converts them to shorter, lower weight molecules. The shorter, lower weight molecules offer less resistance to flow and their ability to maintain viscosity is reduced.		The long chain molecules in VI Improvers are prone to "shearing" with use which reduces their ability to prevent the oil from losing viscosity. This "shearing" occurs when shear stress ruptures the long chain molecules and converts them to shorter, lower weight molecules. The shorter, lower weight molecules offer less resistance to flow and their ability to maintain viscosity is reduced.

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	Like basestock quality, VI Improvers also vary in quality. As with many items the more you pay, the better the finished article and more expensive, usually synthetic oils are likely to incorporate better VI improvers. All other things being equal the less VI improver an oil contains, the better it will stay in grade by resisting viscosity loss.		Like basestock quality, VI Improvers also vary in quality. As with many items the more you pay, the better the finished article and more expensive, usually synthetic oils are likely to incorporate better VI improvers. All other things being equal the less VI improver an oil contains, the better it will stay in grade by resisting viscosity loss.


	'''Which oils require more VI Improvers?'''		'''Which oils require more VI Improvers?'''

	There are two scenarios where large amounts of these polymers are required as a rule.		There are two scenarios where large amounts of these polymers are required as a rule.

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	It is a fact that many synthetics require significantly less VI Improver to work as a multigrade and are therefore less prone to viscosty loss by shearing.		It is a fact that many synthetics require significantly less VI Improver to work as a multigrade and are therefore less prone to viscosty loss by shearing.


	'''HTHS - High temperature High shear'''		'''HTHS - High temperature High shear'''

	A relatively new oil test/specification, the oil is subjected to high temperature 150C and is mechanically sheared at 1 x 10^6 per second. A value of 2.8 or is considered the minumum for normal bearing wear. Here are some HTHS numbers on well known oils, the higher the number the more shear stable the oil; 4's and 5's are excellent numbers and demonstrate basestock quality e.g. Silkolene and Motul.		A relatively new oil test/specification, the oil is subjected to high temperature 150C and is mechanically sheared at 1 x 10^6 per second. A value of 2.8 or is considered the minumum for normal bearing wear. Here are some HTHS numbers on well known oils, the higher the number the more shear stable the oil; 4's and 5's are excellent numbers and demonstrate basestock quality e.g. Silkolene and Motul.

	Castrol RS 10w-60 HTHS 3.70		Castrol RS 10w-60 HTHS 3.70

	Castrol RS 0w-40 HTHS 3.70		Castrol RS 0w-40 HTHS 3.70

	Silkolene PRO S 5w-40 HTHS 4.07		Silkolene PRO S 5w-40 HTHS 4.07

	Motul 300V 10w-40 HTHS 4.19		Motul 300V 10w-40 HTHS 4.19

	Motul 300V 5w-40 HTHS 4.51		Motul 300V 5w-40 HTHS 4.51

	Mobil 1 Motorsport 15w-50 HTHS 5.11		Mobil 1 Motorsport 15w-50 HTHS 5.11

	Silkolene PRO S 10w-50 HTHS 5.11		Silkolene PRO S 10w-50 HTHS 5.11

	Silkolene PRO R 15w-50 HTHS 5.23		Silkolene PRO R 15w-50 HTHS 5.23

	Motul 300V 15w-50 HTHS 5.33		Motul 300V 15w-50 HTHS 5.33


	Most semi synthetics are past their best between 3-5000 miles, synthetics are good for 9000-12000 miles on the road. For track a decent synthetic race oil will last 10 track hours (so long as there is not excessive fuel dilution).		Most semi synthetics are past their best between 3-5000 miles, synthetics are good for 9000-12000 miles on the road. For track a decent synthetic race oil will last 10 track hours (so long as there is not excessive fuel dilution).


	==Other sources of information==		==Other sources of information==

hbaumhardt at 20:18, 23 August 2006

2006-08-23T20:18:23Z

@@ Line 156: / Line 156: @@
 Later specs like LL01 and LL04 are better performing more up to date oils.
 ==Finally==
@@ Line 171: / Line 174: @@
 Like everything in life, you get what you pay for and the cheaper the oil the cheaper the ingredients and lower the performance levels.