5W-20 or 5W-30
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They've actually back-specc'd some of the older Hondas for 5W20, but not the 96 Toyota, I don't believe. The 96 and earlier, I'd run what they spec in the owner's guide. The 99 and 2000 Honda? I'd say the 5W20 would be fine. Others here may want to see you continue with 5W30. Surely the 5W20 of today is better than 5W30 of 7 years back, but 7 years back, there was more ZDDP in the oil, others may be able to say whether that's necessary.
Dr Haas and his friends are using 5w-20 in lots of stuff. A friend of mine has a Ford Excursion, has a bunch of kits, tows a boat trailer, goes to the river (Colorado) all year 'round and used Motorcraft 5w-20. It's been three years, a little over 100k miles, and it does not burn enough in 5k miles to go below the add line before the next oil change. Could it be that these 5w-20's are pretty good oils?
Yeah, yeah, might just could possibly maybe?
Perhaps..
Perhaps..
If the relationship between a base oil's viscosity and the amount of VI improver in the finished formula is what determines HT/HS, then 5w-30 is better b/c it has a higher HT/HS #.
Depends on whether the engine actually benefits from the higher HTHS.
"Exactly! The new 5w20 recommendations are a sham.... Strictly to help meet CAFE standards..."
I agree. The 5W-20 was never recommended until the CAFE standards giving a break to it came out. Then, all of a sudden, some motor vehicle manufactures started recommending 5W-20. I find this very suspect. We have for decades been treated to a never-ending stream of inferior products, and lies about them, by the Big 3 auto makers. When are we going to learn that they can't be trusted? The gullibility of the American public never ceases to amaze me!
I agree. The 5W-20 was never recommended until the CAFE standards giving a break to it came out. Then, all of a sudden, some motor vehicle manufactures started recommending 5W-20. I find this very suspect. We have for decades been treated to a never-ending stream of inferior products, and lies about them, by the Big 3 auto makers. When are we going to learn that they can't be trusted? The gullibility of the American public never ceases to amaze me!
I thought I'd read somewhere that UOA's were not the end-all to the knowing of exactly everything that was happening within the engine.
Seriously, I'm curious, I'd thought I'd read over 100 times on this board, that UOA's were just an idea of what was happening within the engine, but couldn't tell the end all to all parts.
I'm still unsure to this day of whether I believe in thin or thick, but what I am curious about. Is if the thinner oils are supposed to be the best in terms of flow & protection, then why do some auto makers that share the same designed engines call for different oil weights?
And why do other countries that have the same engines call for different weights?
Honestly, I do believe a thinner oil is better for winter; but I don't believe thinner is better in summer - at least not in older engines.
And, if thin was so much better, why wouldn't the dealerships make it a point to USE thinner oil, namingly Toyota dealers?
Seriously, I'm curious, I'd thought I'd read over 100 times on this board, that UOA's were just an idea of what was happening within the engine, but couldn't tell the end all to all parts.
I'm still unsure to this day of whether I believe in thin or thick, but what I am curious about. Is if the thinner oils are supposed to be the best in terms of flow & protection, then why do some auto makers that share the same designed engines call for different oil weights?
And why do other countries that have the same engines call for different weights?
Honestly, I do believe a thinner oil is better for winter; but I don't believe thinner is better in summer - at least not in older engines.
And, if thin was so much better, why wouldn't the dealerships make it a point to USE thinner oil, namingly Toyota dealers?
Ramblin:
- UOAs are a great way to see the rate of wear.
- some auto makers dont have tight enough clearances to benefit from Xw20 oils. The oils would seap/burn.
- It has been stated several times availability plays a huge role in other countries. Car makers won't spec an oil that consumers can't get a hold of. NA is pretty much the only place 5w20 is refined in large volume.
- As for dealerships, they call them "stealerships" for a reason. Most only want to cut cost. 5w20 is not as cheap. BUT, you will find most Ford and Mazda Dealerships do use bulk MC 5w20.
- UOAs are a great way to see the rate of wear.
- some auto makers dont have tight enough clearances to benefit from Xw20 oils. The oils would seap/burn.
- It has been stated several times availability plays a huge role in other countries. Car makers won't spec an oil that consumers can't get a hold of. NA is pretty much the only place 5w20 is refined in large volume.
- As for dealerships, they call them "stealerships" for a reason. Most only want to cut cost. 5w20 is not as cheap. BUT, you will find most Ford and Mazda Dealerships do use bulk MC 5w20.
From everyting I have seen, I am a firm believer in the 5w20's out there. Unfortunately, it's little too thin for my Jeep 4.0L
Most 5W-30 Conventionals shear to 20 weight anyway and most 5W-20 Conventionals (Almost all are actually Synthetic Blends) are very stable.
In Synthetics, Castrol Syntec for example;
5W-30 = 9.7 cSt
5w-20 = 9.0 cSt
Do you really think a 7.2% reduction in viscosity is going to have that much effect?
Still would like to know why then, say the same engine that was produced just a few years ago, spec'd 10w-30 and within the last year or 2, that same engine is now spec'd for 5w-20.
What exactly occured if it's the same engine? This is my point.
Again, I'm not against thinner oils IF they had be requiring their use in the SAME exact engines that are now calling for thinner oils, that once spec'd thicker oils. Even here in the United States, not just other countries.
Yes, the 5w-30 does thin out so much to the point that I don't see why people here on this board are even talking about ever using it versus 5w-20, or why they use it for more then 3k miles, when within the first 1k miles, it's already a thin 5w-20.
I have recently purchased a vehicle that calls for 5w-30, which doesn't make any sense why the manufacture didn't just list 5w-20 instead; as a year later, on this same engine, they're now calling for 5w-20.
THIS is exactly what I'm talking about. This type of situation is what makes some believe that they're simply thinning the oil requirements for sake of MPG.
What exactly occured if it's the same engine? This is my point.
Again, I'm not against thinner oils IF they had be requiring their use in the SAME exact engines that are now calling for thinner oils, that once spec'd thicker oils. Even here in the United States, not just other countries.
Yes, the 5w-30 does thin out so much to the point that I don't see why people here on this board are even talking about ever using it versus 5w-20, or why they use it for more then 3k miles, when within the first 1k miles, it's already a thin 5w-20.
I have recently purchased a vehicle that calls for 5w-30, which doesn't make any sense why the manufacture didn't just list 5w-20 instead; as a year later, on this same engine, they're now calling for 5w-20.
THIS is exactly what I'm talking about. This type of situation is what makes some believe that they're simply thinning the oil requirements for sake of MPG.
Ford/Honda came up with a much more severe test for 5W-20 than API SL requirements.
Ford MC is 40% GII+ / 60% GIII. So it was a superior product to the old SL 5W-30 with its in
some cases high percentage of Group I. Prior to that time 5W-20 may have sheared just as badily as 5W-30.
The reason Ford went to so much trouble Back specing the older models is the EPA
required a certain percentage of new vehicle owners to use 5W-20 in order for the
5W-20 economy test to stand. This meant they had to get market penetration of the 5W-20
in order to insure availablity.
The reason other manufactures didnt go to so much trouble is Ford And Honda
have already done the heavy lifting to get 5W-20 readily available.
The reason certain vehicles still dont get 5W-20 (Ford 4.0 SOHC) is testing showed
an evident need for over 2.6 HT/HS. This makes me believe these vehicles
also should not be run with the low HT/HS SL rated 5W-30 they were speced with.
At the very least they should only be run with a SM/GF-4 5W-30 and I believe
an ACEA A3 rated 5W-30 would be better.
Ok, my other question is, IS the HT/HS higher in an ACEA A3 rated oil versus your typical SM/GF-4 5w-30?
If so, then yes, this helps me understand.
If so, then yes, this helps me understand.
Yes I believe HT/HS standard for SM/GF-4 is 2.9. This would be equivelant to ACEA A1 or A5 if extended drain.
ACEA A3 is 3.5 minimum.
Examples are Valvoline MaxLife Synthetic 5W-30, BMW 5W-30 (Castrol TXT Softec LL-01),
and German Castrol (Castrol Syntec 0W-30 European Formula). Also these should be
more shear stable being synthetic. Also some High Mileage Dinos such as
Pennzoil HM 5W-30 (3.3) and 10W-30 (3.4) come very close.
ACEA A3 is 3.5 minimum.
Examples are Valvoline MaxLife Synthetic 5W-30, BMW 5W-30 (Castrol TXT Softec LL-01),
and German Castrol (Castrol Syntec 0W-30 European Formula). Also these should be
more shear stable being synthetic. Also some High Mileage Dinos such as
Pennzoil HM 5W-30 (3.3) and 10W-30 (3.4) come very close.
As pointed out, A3 is minimum HTHS 3.5.
The 30 weight specification is a range of viscosity’s from 9.3 - 12.5 cST, with most 5w-30’s in NA (North America) falling somewhere around 10.5 cST. The oils viscosity (thickness) at this 10.5 cST probably limits the oil to a HTHS of around 3.0 --the higher the viscosity of the oil, the higher HTHS it will have.
The “thicker” 30 weights are blended up around 12.0cST so they can get over the 3.5 HTHS and make an A3 rating. The problem with the “thicker” 30 weights though, is that they don’t deliver as good gas mileage as thinner oils do. One of the reasons almost all NA 5w-30’s are blended below 11.0cST is to meet the API fuel economy requirements for economy. This has the side effect of ruling them out of an A3 designation because any oil below 11.0cST likely can’t make the 3.5 HTHS rating required for A3.
The 30 weight specification is a range of viscosity’s from 9.3 - 12.5 cST, with most 5w-30’s in NA (North America) falling somewhere around 10.5 cST. The oils viscosity (thickness) at this 10.5 cST probably limits the oil to a HTHS of around 3.0 --the higher the viscosity of the oil, the higher HTHS it will have.
The “thicker” 30 weights are blended up around 12.0cST so they can get over the 3.5 HTHS and make an A3 rating. The problem with the “thicker” 30 weights though, is that they don’t deliver as good gas mileage as thinner oils do. One of the reasons almost all NA 5w-30’s are blended below 11.0cST is to meet the API fuel economy requirements for economy. This has the side effect of ruling them out of an A3 designation because any oil below 11.0cST likely can’t make the 3.5 HTHS rating required for A3.
You have to realize that the automobile business is very unique, in that most business comes from word of mouth. I have a few family members who will only buy hondas and toyotas because they "hear" people boast about their reliability. Why has Toyota become so popular, yes because of strong word of mouth advertising about their bullet proof reliability. I doubt Toyota would compromise reliability to boost CAFE numbers slightly. I would bet that they have done their research and its been proven to them that 5w20 is just as good as 5w30 if not better.
Exactly, so why doesn't Toyota recommend 5w-20 for my engine, if they do so believe in the 5w-20 viscosity?
FWIW - I'm running GC 0w-30 in this engine that they've recommended 5w-30 for; cause, I too agree, that 5w-30 oils are a waste of time.
I do run a mixture of half/half 5w/10w-30 in an Isuzu engine in the winter, Valvoine Maxlife to be precise, because it's manual says NOT to use anything thinner then 10w-30 unless cold starts are a problem. In this truck's situation, I wish Maxlife had a 0w-30 or a 5w-40.
FWIW - I'm running GC 0w-30 in this engine that they've recommended 5w-30 for; cause, I too agree, that 5w-30 oils are a waste of time.
I do run a mixture of half/half 5w/10w-30 in an Isuzu engine in the winter, Valvoine Maxlife to be precise, because it's manual says NOT to use anything thinner then 10w-30 unless cold starts are a problem. In this truck's situation, I wish Maxlife had a 0w-30 or a 5w-40.
Forgot to add, that I mix the two oil weights 5w/10w-30 hoping to prevent the sheering back issue.
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