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So I read a suggestion- but am not going to do it unless its plausible.
That using a lighter weight oil is better for your engine. Makes sense right? Less resistance, the less load on the engine, more hp to the wheels. My question is why not do it? Do car companies worry about oil leaks and thats why a lighter weight is not suggested or is there another reason?So my car takes 5W-30. What would happen if I switched to 0W-30?
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Less resistance more wear!!!
The lower the viscosity, the more wear will inevitably occur. This is why it is best to use the proper oil viscosity recommended by the auto manufacturer as it will protect hot and at cold start ups. Obviously a 10W-10 motor oil won’t have the film strength to prevent engine wear at full operating temperature like a 5W-20, 10W-30 or 5W-30 motor oil for example.
The VI additives have the effect of keeping the oil from thinning excessively when heated. The actual mechanics of this system are a little more complex in that these additives are added to a thinner oil so that it will be fluid at a cold temperature. The VI additives then prevent thinning as the oil is heated so that it now can pass the SAE viscosity rating at 210. For example; if you have a SAE 10 motor oil it will flow like a 10W at the colder temperature. But at 210 degrees it will be a SAE 10 giving us a 10W-10 or SAE 10 viscosity rating. Obviously this is good at cold start up, but terrible at engine operating temperature especially in warmer climates. But by adding the VI additives we can prevent the oil from thinning as it is heated to achieve higher viscosity numbers at 210 degrees. This is how they make a petroleum based motor oil function for the 10W-30 rating. The farther the temperature range, like with a 10W-40, then more VI additives are used. With me so far? Good, now for the bad news.
Drawbacks of Viscosity Improving additives
Multi-grade motor oils perform a great service not being too thick at cold startup to prevent engine wear by providing more instantaneous oil flow to critical engine parts. However, there is a draw back. These additives shear back in high heat or during high shear force operation and break down causing some sludging. What’s worse is once the additive begins to be depleted the motor oil no long resists thinning so now you have a thinner motor oil at 210 degrees. Your 10W-30 motor oil can easily become a 10W-20 or even a SAE 10 (10W-10) motor oil. I don’t have to tell you why that is bad. The more VI additives the worse the problem which is why auto manufacturers decided to steer car owners away from motor oils loaded with VI additives like the 10W-40 and 20W-50 viscosities.
The less change a motor oil has from high to low temperatures gives it a high Viscosity Index. Synthetic motor oils that are made from Group IV (4) PAO base stocks have Viscosity Indexes of more than 150 because they are manufactured to be a lubricant and don’t have the paraffin that causes the thickening as they cool. But petroleum based motor oils (Group I (1) & II (2)) usually have Viscosity Indexes of less than 140 because they tend to thicken more at the colder temperature due to the paraffin despite the addition of Viscosity Improving additives. The higher the Viscosity Index number the less thinning and thickening the motor oil has. In other words, high number good, low number bad. Low numbers thicken more as they cool and thin more hot. You see these Viscosity Index ratings posted on data sheets of motor oils provided by the manufacturer.
As already mentioned, VI improving additives can shear back under pressure and high heat conditions leaving the motor oil unable to protect the engine properly under high heat conditions and cause sludging. Also there is a limit to how much viscosity improving additives can be added without affecting the rest of the motor oil’s chemistry. Auto manufacturers have moved away from some motor oils that require a lot of viscosity improving additives, like the 10W-40 and 20W-50 motor oils, to blends that require less viscosity additives like the 5W-20, 5W-30 and 10W-30 motor oils. Because stress loads on multi viscosity motor oils can also cause thinning many racers choose to use a straight weight petroleum racing motor oil or a PAO based Synthetic which do not have the VI additives. But only the Group IV (4) PAO based synthetics don’t need VI additives. Read on to learn why:Less resistance more wear!!!
The lower the viscosity, the more wear will inevitably occur. This is why it is best to use the proper oil viscosity recommended by the auto manufacturer as it will protect hot and at cold start ups. Obviously a 10W-10 motor oil won’t have the film strength to prevent engine wear at full operating temperature like a 5W-20, 10W-30 or 5W-30 motor oil for example.
The VI additives have the effect of keeping the oil from thinning excessively when heated. The actual mechanics of this system are a little more complex in that these additives are added to a thinner oil so that it will be fluid at a cold temperature. The VI additives then prevent thinning as the oil is heated so that it now can pass the SAE viscosity rating at 210. For example; if you have a SAE 10 motor oil it will flow like a 10W at the colder temperature. But at 210 degrees it will be a SAE 10 giving us a 10W-10 or SAE 10 viscosity rating. Obviously this is good at cold start up, but terrible at engine operating temperature especially in warmer climates. But by adding the VI additives we can prevent the oil from thinning as it is heated to achieve higher viscosity numbers at 210 degrees. This is how they make a petroleum based motor oil function for the 10W-30 rating. The farther the temperature range, like with a 10W-40, then more VI additives are used. With me so far? Good, now for the bad news.
Drawbacks of Viscosity Improving additives
Multi-grade motor oils perform a great service not being too thick at cold startup to prevent engine wear by providing more instantaneous oil flow to critical engine parts. However, there is a draw back. These additives shear back in high heat or during high shear force operation and break down causing some sludging. What’s worse is once the additive begins to be depleted the motor oil no long resists thinning so now you have a thinner motor oil at 210 degrees. Your 10W-30 motor oil can easily become a 10W-20 or even a SAE 10 (10W-10) motor oil. I don’t have to tell you why that is bad. The more VI additives the worse the problem which is why auto manufacturers decided to steer car owners away from motor oils loaded with VI additives like the 10W-40 and 20W-50 viscosities.
The less change a motor oil has from high to low temperatures gives it a high Viscosity Index. Synthetic motor oils that are made from Group IV (4) PAO base stocks have Viscosity Indexes of more than 150 because they are manufactured to be a lubricant and don’t have the paraffin that causes the thickening as they cool. But petroleum based motor oils (Group I (1) & II (2)) usually have Viscosity Indexes of less than 140 because they tend to thicken more at the colder temperature due to the paraffin despite the addition of Viscosity Improving additives. The higher the Viscosity Index number the less thinning and thickening the motor oil has. In other words, high number good, low number bad. Low numbers thicken more as they cool and thin more hot. You see these Viscosity Index ratings posted on data sheets of motor oils provided by the manufacturer.
As already mentioned, VI improving additives can shear back under pressure and high heat conditions leaving the motor oil unable to protect the engine properly under high heat conditions and cause sludging. Also there is a limit to how much viscosity improving additives can be added without affecting the rest of the motor oil’s chemistry. Auto manufacturers have moved away from some motor oils that require a lot of viscosity improving additives, like the 10W-40 and 20W-50 motor oils, to blends that require less viscosity additives like the 5W-20, 5W-30 and 10W-30 motor oils. Because stress loads on multi viscosity motor oils can also cause thinning many racers choose to use a straight weight petroleum racing motor oil or a PAO based Synthetic which do not have the VI additives. But only the Group IV (4) PAO based synthetics don’t need VI additives. Read on to learn why:What type of car?
what engine?
what year?
How many miles?I can tell you for-sure you will lower your oil pressure using that oil.
My truck calls for 10-30 but i ran 10-40 but i also have almost 300k. I did this to bring the oil pressure up…. Its like dreamer would say (Band aid)
Leave ur oil type alone…
Group IV (4) and Group V (5) base oil (synthetics) are chemically made from uniform molecules with no paraffin and don’t need Viscosity Additives. However, in recent years Group III (3) based oils have been labeled “synthetic” through a legal loophole. These are petroleum based Group II (2) oils that have had the sulfur refined out making them more pure and longer lasting. Group III (3) “synthetic” motor oils must employ Viscosity Additives being petroleum based.
Group V (5) based synthetics are usually not compatible with petroleum or petroleum fuels and have poor seal swell. These are used for air compressors, hydraulics, etc. It’s the Group IV (4) PAO based synthetics that make the best motor oils. They are compatible with petroleum based oils and fuels plus they have better seal swell than petroleum. Typically PAO based motor oils use no Viscosity Additives yet pass the multi-grade viscosity requirements as a straight weight! This makes them ideal under a greater temperature range. One advantage of not having to employ Viscosity Improving additives is having a more pure undiluted lubricant that can be loaded with more longevity and performance additives to keep the oil cleaner longer with better mileage/horsepower.What type of car?
what engine?
what year?
How many miles?I can tell you for-sure you will lower your oil pressure using that oil.
My truck calls for 10-30 but i ran 10-40 but i also have almost 300k. I did this to bring the oil pressure up…. Its like dreamer would say (Band aid)
Leave ur oil type alone…
Group IV (4) and Group V (5) base oil (synthetics) are chemically made from uniform molecules with no paraffin and don’t need Viscosity Additives. However, in recent years Group III (3) based oils have been labeled “synthetic” through a legal loophole. These are petroleum based Group II (2) oils that have had the sulfur refined out making them more pure and longer lasting. Group III (3) “synthetic” motor oils must employ Viscosity Additives being petroleum based.
Group V (5) based synthetics are usually not compatible with petroleum or petroleum fuels and have poor seal swell. These are used for air compressors, hydraulics, etc. It’s the Group IV (4) PAO based synthetics that make the best motor oils. They are compatible with petroleum based oils and fuels plus they have better seal swell than petroleum. Typically PAO based motor oils use no Viscosity Additives yet pass the multi-grade viscosity requirements as a straight weight! This makes them ideal under a greater temperature range. One advantage of not having to employ Viscosity Improving additives is having a more pure undiluted lubricant that can be loaded with more longevity and performance additives to keep the oil cleaner longer with better mileage/horsepower.There is no difference between 0w30 and 5w30 when the oil is at operating temperature.
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=cfrm Wealth of oil info at these forums.
There is no difference between 0w30 and 5w30 when the oil is at operating temperature.
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=cfrm Wealth of oil info at these forums.
[quote=”OnThe7ThDayFord” post=32592]My truck calls for 10-30 but i ran 10-40 but i also have almost 300k. I did this to bring the oil pressure up…. Its like dreamer would say (Band aid)[/quote]
Correct me if I am wrong here, but what is this accomplishing? You are moving to thicker oil and gaining more pressure when the motor is warm, but that added pressure is from the thicker oil causing more resistance to flow. While you do get higher pressure, you also get lower flow volume, unless that’s what you are trying to achieve.
[quote=”OnThe7ThDayFord” post=32592]My truck calls for 10-30 but i ran 10-40 but i also have almost 300k. I did this to bring the oil pressure up…. Its like dreamer would say (Band aid)[/quote]
Correct me if I am wrong here, but what is this accomplishing? You are moving to thicker oil and gaining more pressure when the motor is warm, but that added pressure is from the thicker oil causing more resistance to flow. While you do get higher pressure, you also get lower flow volume, unless that’s what you are trying to achieve.
I would agree. Oil pressure is a result of system resistance as Eric already covered. Thinner oils would lower the oil pressure which is not bad in a healthy engine AFAIK. Thinner oil means higher flow rates which is what transports heat away from the engine and brings new additives the site of high torque/pressure. I believe the US gas consumption has moved oil viscosities to xW20 and no adverse effects has been observed within the lifetime of a normal vehicle. This is not the same as recommending low viscosity oil for engines not made for it or if your temp range requires thicker oil.
I would agree. Oil pressure is a result of system resistance as Eric already covered. Thinner oils would lower the oil pressure which is not bad in a healthy engine AFAIK. Thinner oil means higher flow rates which is what transports heat away from the engine and brings new additives the site of high torque/pressure. I believe the US gas consumption has moved oil viscosities to xW20 and no adverse effects has been observed within the lifetime of a normal vehicle. This is not the same as recommending low viscosity oil for engines not made for it or if your temp range requires thicker oil.
[quote=”jthomsonmain” post=41797][quote=”OnThe7ThDayFord” post=32592]My truck calls for 10-30 but i ran 10-40 but i also have almost 300k. I did this to bring the oil pressure up…. Its like dreamer would say (Band aid)[/quote]
Correct me if I am wrong here, but what is this accomplishing? You are moving to thicker oil and gaining more pressure when the motor is warm, but that added pressure is from the thicker oil causing more resistance to flow. While you do get higher pressure, you also get lower flow volume, unless that’s what you are trying to achieve.[/quote]
I like the way you think.
Pressure is resistance to flow.
Really what should be on a lube system is a flow meter and a pressure gauge, since you want to know oil is flowing. Remember you could have oil pressure with no flow, and the oil is just blowing over the relief built into the pump(or worse the system in the filter)but you also want pressure since it helps suspend the bearings in a film of oil.Another strange downside to having a higher oil pressure is heat, NO its not created from the pressure, it is created from the force on the oil being released. I know its backwards from gasses.
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