Ford started recommending 5W-20 for 4.6L Mustang GT engines back in 2001 I believe. Before that, it was 5w30. Since then they have "back-spec'ed" 5W-20 to the 1996 Mustang GT with the 4.6L engine which was the first year Ford started using this engine in the Mustang GT. I have a 1998 Ford Mustang GT and intend to continue using Mobil 1 5w30 in it. It runs great!
Ford's write up on their reasons for use of 5W-20
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Based on what? Is Ford assuming no one speeds and people only drive on the highway at exactly 55 MPH? I think they are full of it.
Excellent points!
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I'm unsure what point you're making with the highlighted statement there, BTJ
In the case of PZ 5w-20 vs. 5w30 ..the difference in viscosity is 74% or 135%, depending on which way you go, across the board. Now it my not be linear all the way out but should be for a good practical distance.
I really am amazed at how the vast span, within which these two oils are identical at slightly different temps, is ignored.
Vad--anal? No. People are going to do whatever they want. If it's just for cafe reasons it's brilliant. If it protects the same or better and improves gas mileage slightly than it is better for all. If your car specs 5w20 and you choose not to use it for whatever reason that's cool. Nobody cares! It's your car. I don't care what happens overseas! Who cares that honda engines spec 5w30 in europe. This isn't europe. It's just an oil recommendation. Not a crisis.
I have been away for a few days so I am playing catch-up on this thread.
My skepticism about 5W-20 is only that why is 5w30 no longer any good? Many of the engines and autos now recommending 5W-20 use to use 5w30 without any problems.
5W-20 is a good oil, but I don't see how it is better than 5w30 except for a very slight and negligible improvements in fuel economy which are generally 0.5% compared to 5w30.
5w30 offers better hot engine protection since it is thicker hot than 5W-20 hot. Therefore the film on engine parts is thicker.
If the temperature outside is above 0 F (yes F not C), then 10w30 will work just fine in engines requiring 5w30. In fact, this is seen in numerous owner's manuals.
Of course going too thick is bad. There is no way I would run 10W-40 or 15w40 or 5W-50 or 20W-50 in my 1998 Ford Mustang GT.
All I am saying is what improvements are there by using 5W-20 instead of 5w30 other than very slight and negligible improvements in fuel economy?
I am thinking about going to Mobil 1 0w30 which offers the better cold weather and first engine start up performance and protection that the 5W-XX motor oils but also provides the same performance and protection of 5w30 and 10w30 hot.
My skepticism about 5W-20 is only that why is 5w30 no longer any good? Many of the engines and autos now recommending 5W-20 use to use 5w30 without any problems.
5W-20 is a good oil, but I don't see how it is better than 5w30 except for a very slight and negligible improvements in fuel economy which are generally 0.5% compared to 5w30.
5w30 offers better hot engine protection since it is thicker hot than 5W-20 hot. Therefore the film on engine parts is thicker.
If the temperature outside is above 0 F (yes F not C), then 10w30 will work just fine in engines requiring 5w30. In fact, this is seen in numerous owner's manuals.
Of course going too thick is bad. There is no way I would run 10W-40 or 15w40 or 5W-50 or 20W-50 in my 1998 Ford Mustang GT.
All I am saying is what improvements are there by using 5W-20 instead of 5w30 other than very slight and negligible improvements in fuel economy?
I am thinking about going to Mobil 1 0w30 which offers the better cold weather and first engine start up performance and protection that the 5W-XX motor oils but also provides the same performance and protection of 5w30 and 10w30 hot.
When the manufacturers spec a 0w-10 oil for their new engines, everyone, here, will say 0w-10 is too thin. You need the protection of a more robust oil like a 5w-20. You need the thicker 20 weight oil, especially when pulling a load. Only a 20 weight oil will offer the protection needed. The manufacturer just wants to improve the gas mileage a fraction of a percent, overall. Don't be fooled. Use a heaver, more robust oil like a 5w-20.
OK. In order to have a 5W rating, the oil must pour at -25 C through a small hole of which size I cannot remember. -25 C is -13 F. That is F'n COLD!quote:
Originally posted by Gary Allan:
I'm unsure what point you're making with the highlighted statement there, BTJ
In the case of PZ 5w-20 vs. 5w30 ..the difference in viscosity is 74% or 135%, depending on which way you go, across the board. Now it my not be linear all the way out but should be for a good practical distance.
I really am amazed at how the vast span, within which these two oils are identical at slightly different temps, is ignored.
Now if 5W-20 is thinner across the board, why does it have a 5W rating? Shouldn't it actually have a 0W rating instead?
Also, if 5W-20 is thinner across the board, it becomes apparent why there is skepticism about its hot temperature performance and protection especially in sports cars and trucks that tow heavy loads.
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Look at the spec's here use the pull down menus to find the multivisc oils and compare the 5w ratings. Not all 5w's are created equal ..just as 30 weights span a decent range. I mean it's not like they all are identical at the same temp.
Now for the upper end, yes, 5w-20 will be thinner then 5w30. So? How does that mandate that there will be less protection? Or rather, how does that mandate more wear? You're making assumptions that the 30 weight is the minimum needed for the task. Suppose, as we've known for sometime, that 30 weight was required to not go below a 20 weight over the oci? Just because they "may" have managed to reduce the shearing ...why does it mean that NOW you need that 30 weight ..when you didn't for about 30 years
(read this twice if you would like)
Also, Buford, as you go above 100C, visocities converge. That is, they become more "alike". What's a big difference at 0F ..is marginal @125C. I think it's a difference of 1.2 CST.
Now for the upper end, yes, 5w-20 will be thinner then 5w30. So? How does that mandate that there will be less protection? Or rather, how does that mandate more wear? You're making assumptions that the 30 weight is the minimum needed for the task. Suppose, as we've known for sometime, that 30 weight was required to not go below a 20 weight over the oci? Just because they "may" have managed to reduce the shearing ...why does it mean that NOW you need that 30 weight ..when you didn't for about 30 years
Also, Buford, as you go above 100C, visocities converge. That is, they become more "alike". What's a big difference at 0F ..is marginal @125C. I think it's a difference of 1.2 CST.
Let's wait untill the "Time machine" comes on-line.quote:
Originally posted by LarryL:
When the manufacturers spec a 0w-10 oil for their new engines, everyone, here, will say 0w-10 is too thin. You need the protection of a more robust oil like a 5w-20. You need the thicker 20 weight oil, especially when pulling a load. Only a 20 weight oil will offer the protection needed. The manufacturer just wants to improve the gas mileage a fraction of a percent, overall. Don't be fooled. Use a heaver, more robust oil like a 5w-20.
Until then any speculation abouth the future would remain just that - a speculation.
And wait a second. Almost forgot.
OK, here we go.
There is the EPA letter that Blue99 posted. It says (broken up as you can read the whole thing)...
http://www.epa.gov/otaq/cert/dearmfr/ccd0006.pdf
"By using 5W20 [sic] engine oil in certification and fuel economy test vehicles, these manufacturers expect to realize a fuel economy benefit relative to the engine oils that they would otherwise have used."
So in a nutshell the only valid reason to going to 5W-20 over 5w30 was for fuel economy. I guess this was originally done for sales, but it doesn't mean much since the fuel economy improvement is 0.5% on average. So if I had a car or truck that got 20 MPG on the highway using 5w30 motor oil, the use of 5W-20 motor oil would yield 20.1 MPG. It is MEANINGLESS.
And Americans could care less about fuel economy. If we did, there would be no Mustangs or Camaros or Chargers or big trucks or SUVs, etc. We would be driving Yugos if we cared that much about it.
I am a fast reader and am playing catch up thanks to a bad hard drive that required replacement and a Windows XP Pro reinstall, lol.quote:
Originally posted by sxg6:
Geez Buford.. 5 consecutive posts within a 15 minute time frame is goin a little overboard.
Prior to my Windows reinstall, I had a link in my bookmarks that had a really good article about 5W-20 protection. As I remember, the film created by 5W-20 was much thinner than the film created by 5w30. Anyway, the gist of the article was that if a dirt particle worked its way between the piston and cylinder wall that the film created by 5W-20 might be compromised therefore creating wear whereas the film created by 5w30 would suspend this dirt particle easily. I cannot remember what size this dirt particle was, but it was small. And I think, according to the article, that a dirt particle too big for the film created by 5w30 to be suspended would be too big to get between the piston and cylinder wall. If I can find that article, I will post it here.quote:
Originally posted by Gary Allan:
Look at the spec's here use the pull down menus to find the multivisc oils and compare the 5w ratings. Not all 5w's are created equal ..just as 30 weights span a decent range. I mean it's not like they all are identical at the same temp.
Now for the upper end, yes, 5w-20 will be thinner then 5w30. So? How does that mandate that there will be less protection? Or rather, how does that mandate more wear? You're making assumptions that the 30 weight is the minimum needed for the task. Suppose, as we've known for sometime, that 30 weight was required to not go below a 20 weight over the oci? Just because they "may" have managed to reduce the shearing ...why does it mean that NOW you need that 30 weight ..when you didn't for about 30 years(read this twice if you would like)
Also, Buford, as you go above 100C, visocities converge. That is, they become more "alike". What's a big difference at 0F ..is marginal @125C. I think it's a difference of 1.2 CST.
Here is an article that is pretty close to the article I was referring to...
http://www.machinerylubrication.com/article_detail.asp?articleid=518&relatedbookgroup=Maintenance
Some quotes from it...
"Any abrasive particles equal to or larger than the oil film thickness will cause wear. Filters are necessary to keep contaminants small. The other side of the equation is oil film thickness. Thicker oil films can accommodate larger contaminants."
"If an SAE 50 oil at 260°F is as thin as an SAE 20 oil at 190°F, imagine how thin the oil film becomes when you are using an SAE 5W-20 and your engine overheats. When an engine overheats, the oil film becomes dangerously thin and can rupture."
"To determine if SAE 5W-20 oils provide the same level of protection as SAE 5w30 oils, Dagenham Motors in England, one of the largest Ford dealers in Europe, was consulted. SAE 5w30 is required for warranty purposes in England, and SAE 5W-20 is not even available. If SAE 5W-20 were better for both fuel economy and wear, why would Ford not recommend it for its same engines in Europe?"
"Certainly engines that have experienced significant ring and liner wear benefit from thicker oils. Thicker oil use results in compression increases, performance improvements and reduced oil consumption."
"The best protection against wear is probably a product that is a little thicker (such as SAE 10w30 or 15w40) and has more antiwear additives than the oils that support the warranty. The best oil for your vehicle depends on your driving habits, the age of your engine and the climate you drive in, but it is not necessarily the type of oil specified in the owner’s manual or stamped on the dipstick."
http://www.machinerylubrication.com/article_detail.asp?articleid=518&relatedbookgroup=Maintenance
Some quotes from it...
"Any abrasive particles equal to or larger than the oil film thickness will cause wear. Filters are necessary to keep contaminants small. The other side of the equation is oil film thickness. Thicker oil films can accommodate larger contaminants."
"If an SAE 50 oil at 260°F is as thin as an SAE 20 oil at 190°F, imagine how thin the oil film becomes when you are using an SAE 5W-20 and your engine overheats. When an engine overheats, the oil film becomes dangerously thin and can rupture."
"To determine if SAE 5W-20 oils provide the same level of protection as SAE 5w30 oils, Dagenham Motors in England, one of the largest Ford dealers in Europe, was consulted. SAE 5w30 is required for warranty purposes in England, and SAE 5W-20 is not even available. If SAE 5W-20 were better for both fuel economy and wear, why would Ford not recommend it for its same engines in Europe?"
"Certainly engines that have experienced significant ring and liner wear benefit from thicker oils. Thicker oil use results in compression increases, performance improvements and reduced oil consumption."
"The best protection against wear is probably a product that is a little thicker (such as SAE 10w30 or 15w40) and has more antiwear additives than the oils that support the warranty. The best oil for your vehicle depends on your driving habits, the age of your engine and the climate you drive in, but it is not necessarily the type of oil specified in the owner’s manual or stamped on the dipstick."
I never thought that oil choice debates could be so entertaining, or maybe such a time waste.
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