DF Sales&Marketing
Oil Tech Moderator
In part from lubes’n greases article titled “the ups and (mostly) downs of viscosity.
Viscosity is perhaps the most mis-understood word in lubrication, but it is really quite simple if you think of it not as most people do and refer it to “thick-ness” of the oil, but rather the “resistance to flow” as it’s main characteristic.
Steve swedberg, an automotive technical writer, for “lubes’ngreases” magazine recently explained why the automotive manufacturers have been lowering the viscosity recommendations for their cars and light duty trucks.
If the first thing which comes to mind is “money” then you hit the nail on the head. If the first thing you also thought of which comes to mind is “government intervention,” you also hit the nail on the head.
The money and the government intervention end of it comes from stiff penalties imposed by mandated regulations concerning gasoline engine miles per gallon. Currently the “café” (corporate average fuel economy) requirement is 27.5 mpg …..this will be increased to an astounding 35.5 mpg in 2016. One of the ways to help increase mpg is using an oil with less “resistance to flow” by lowering the weight of the oil. If the manufacturer cannot meet the requirements, they are fined ten dollars for each .01 of the deficient amount—multiply that by every million cars they produce, you can see how astronomical it can get.
Many have questioned the sensibility of using a low viscosity oil in climates which have very harsh summer weather. Another example which many have also wondered is; what other areas the government is going to intervene with in their own agendas that May be more costly to the consumer besides viscosity and the reduction of zddp in todays oil and using it in older engines.
Here is some of the background history of where we were and where we are now as far as viscosity is concerned as reported by steve swedberg:
“first, let’s start with some definitions. Basically, viscosity is the resistance of any material to flow. The resistance is caused by the internal friction of the molecules moving against each other.
For a long time, engines were built using sae 30 as the lubricant standard, and the absolute viscosity of sae 30 at the operating temperature of the engine was used specifically for design purposes. That went on well into the 1980s. That’s when automobile and engine manufacturers finally recognized that lower viscosity oils have an inherent advantage over heavier oils in terms of friction reduction– lower viscosity means less internal friction in the oil. Lighter oils resulted in lower friction in the engine, which gave better fuel economy. Ever since, the bottom line in all of the reduced engine oil viscosity efforts is to improve fuel economy.
In the 1970s oems began to prefer multigrade engine oils and sae 10w40 ruled as it gave excellent performance in a wide range of operating temperatures; it also had a fuel economy benefit versus sae 30. The next step, sae 10w30, was a bit better in fuel economy than sae 10w40 and also provided good performance in a wide operating temperature range. This was also an era that saw friction modifiers introduced into oil formulations.
The 1980s brought the introduction of sae 5w30 which improved fuel economy even more, and with design changes to the engine (such as roller followers instead of flat tappet valve lifters) offered good protection for the hardware. These oils gave even better low-temperature performance. Sae 5w30 was “king of the hill” for the next 20 years or so, in addition, there were improvements in friction modifiers as well as astm engine sequence tests to measure fuel economy.
So from its once dominant spot on top of the viscosity pile, sae 10w40 today is only 6 percent of the u.s. Passenger car oil market, while 5w30 is the market “heavyweight” with 47 percent share according to infineum.
You should be able to see a trend here. The “w” side of the sae grade has the greatest impact on fuel economy, while the second viscosity number is, well, secondary. In addition the friction modifiers present also add to the oils’ fuel economy benefits.
This is a good time to ask how fuel economy became so important for engine oils, to where it seemingly outweighs other aspects like wear protection, oxidation stability, cold cranking and evaporation. And here is where government and big money raise their heads.
In the 1970s, legislation was passed mandating that average fuel economy for each passenger car manufacturer should be a minimum of 27.5 mpg, to be reached by the 1985 model year. This is the so-called café, or corporate average fuel economy requirement. At the time this legislation was passed in 1977, the average fuel economy of automobiles in the u.s. Was around 15 mpg.
The oems knew that their best-selling and highest–margin vehicles such as suvs, vans, full-size automobiles and pickups, couldn’t realistically meet that target and deadline. So they built small vehicles with very high fuel economy to offset the fuel guzzlers; averaged together, the fleet would hit the target.
A similar situation exists today, with new legislation which will require oems post café numbers of 35.5 mpg beginning in 2016, not even four years away. That brings immediate pressure to develop more fuel miserly vehicles and to reduce oil viscosities even more.”
Viscosity is perhaps the most mis-understood word in lubrication, but it is really quite simple if you think of it not as most people do and refer it to “thick-ness” of the oil, but rather the “resistance to flow” as it’s main characteristic.
Steve swedberg, an automotive technical writer, for “lubes’ngreases” magazine recently explained why the automotive manufacturers have been lowering the viscosity recommendations for their cars and light duty trucks.
If the first thing which comes to mind is “money” then you hit the nail on the head. If the first thing you also thought of which comes to mind is “government intervention,” you also hit the nail on the head.
The money and the government intervention end of it comes from stiff penalties imposed by mandated regulations concerning gasoline engine miles per gallon. Currently the “café” (corporate average fuel economy) requirement is 27.5 mpg …..this will be increased to an astounding 35.5 mpg in 2016. One of the ways to help increase mpg is using an oil with less “resistance to flow” by lowering the weight of the oil. If the manufacturer cannot meet the requirements, they are fined ten dollars for each .01 of the deficient amount—multiply that by every million cars they produce, you can see how astronomical it can get.
Many have questioned the sensibility of using a low viscosity oil in climates which have very harsh summer weather. Another example which many have also wondered is; what other areas the government is going to intervene with in their own agendas that May be more costly to the consumer besides viscosity and the reduction of zddp in todays oil and using it in older engines.
Here is some of the background history of where we were and where we are now as far as viscosity is concerned as reported by steve swedberg:
“first, let’s start with some definitions. Basically, viscosity is the resistance of any material to flow. The resistance is caused by the internal friction of the molecules moving against each other.
For a long time, engines were built using sae 30 as the lubricant standard, and the absolute viscosity of sae 30 at the operating temperature of the engine was used specifically for design purposes. That went on well into the 1980s. That’s when automobile and engine manufacturers finally recognized that lower viscosity oils have an inherent advantage over heavier oils in terms of friction reduction– lower viscosity means less internal friction in the oil. Lighter oils resulted in lower friction in the engine, which gave better fuel economy. Ever since, the bottom line in all of the reduced engine oil viscosity efforts is to improve fuel economy.
In the 1970s oems began to prefer multigrade engine oils and sae 10w40 ruled as it gave excellent performance in a wide range of operating temperatures; it also had a fuel economy benefit versus sae 30. The next step, sae 10w30, was a bit better in fuel economy than sae 10w40 and also provided good performance in a wide operating temperature range. This was also an era that saw friction modifiers introduced into oil formulations.
The 1980s brought the introduction of sae 5w30 which improved fuel economy even more, and with design changes to the engine (such as roller followers instead of flat tappet valve lifters) offered good protection for the hardware. These oils gave even better low-temperature performance. Sae 5w30 was “king of the hill” for the next 20 years or so, in addition, there were improvements in friction modifiers as well as astm engine sequence tests to measure fuel economy.
So from its once dominant spot on top of the viscosity pile, sae 10w40 today is only 6 percent of the u.s. Passenger car oil market, while 5w30 is the market “heavyweight” with 47 percent share according to infineum.
You should be able to see a trend here. The “w” side of the sae grade has the greatest impact on fuel economy, while the second viscosity number is, well, secondary. In addition the friction modifiers present also add to the oils’ fuel economy benefits.
This is a good time to ask how fuel economy became so important for engine oils, to where it seemingly outweighs other aspects like wear protection, oxidation stability, cold cranking and evaporation. And here is where government and big money raise their heads.
In the 1970s, legislation was passed mandating that average fuel economy for each passenger car manufacturer should be a minimum of 27.5 mpg, to be reached by the 1985 model year. This is the so-called café, or corporate average fuel economy requirement. At the time this legislation was passed in 1977, the average fuel economy of automobiles in the u.s. Was around 15 mpg.
The oems knew that their best-selling and highest–margin vehicles such as suvs, vans, full-size automobiles and pickups, couldn’t realistically meet that target and deadline. So they built small vehicles with very high fuel economy to offset the fuel guzzlers; averaged together, the fleet would hit the target.
A similar situation exists today, with new legislation which will require oems post café numbers of 35.5 mpg beginning in 2016, not even four years away. That brings immediate pressure to develop more fuel miserly vehicles and to reduce oil viscosities even more.”