Fixin to Run Straight 30 This Summer

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Originally Posted By: TallPaul
Besides, does anyone need to worry about a 30 weight getting too thin in this day of almost everything now specifying 5w20?


That may be stretching it a little. I only know of Ford and Honda recommending 20wt oils. (I may be wrong). I don't buy into 20wt oils because they are just a tool for better MPG's for the manufacturer. Not that 20wt oils are bad - there's plenty of proof that it works from fellas right on this forum. I just believe a 5w30 or 10w30 is better for MY needs.

As for straight 30 oil - my dad always used it in Diesels because it was suggested as long as the weather permitted it. I think, personally, that SAE30 is obsolete with the much better oils today in multi-weights. JMO.
 
Originally Posted By: GMBoy

I only know of Ford and Honda recommending 20wt oils. (I may be wrong).


You are.

Mitsubishi, Chrysler and Toyota are recommending 5W-20 in most (if not all) of their most popular 4 cylinder engines now for a few years. Together with Honda and Ford this is more than half of the cars on the road today with a factory fill of 5W-20.
 
Interesting the chart Peter_Pan posted says use of 10w30 above 80F may cause increased oil consumption. For temps above 80F it only recommends SAE 30 or Synthetic 5w30 (the 5w part surely only for the lower part of the arrow). Now I am interested in seeing if consumption in the Aerostar goes down with SAE 30. Right now it's using a quart every 1000 miles.
 
Originally Posted By: TallPaul
Interesting the chart Peter_Pan posted says use of 10w30 above 80F may cause increased oil consumption. For temps above 80F it only recommends SAE 30 or Synthetic 5w30 (the 5w part surely only for the lower part of the arrow). Now I am interested in seeing if consumption in the Aerostar goes down with SAE 30. Right now it's using a quart every 1000 miles.


One note: That chart is for air cooled Briggs & Stratton engines.
Those engines run a lot hotter than water cooled engines so I don't think you should see a noticeable change in consumption as water cooled engines don't get as hot to make that much difference but keep us posted, this should prove interesting!
 
Originally Posted By: aquariuscsm
I`d think by design a straight weight oil would handle heat and stress better than a multi grade. Because isn`t a 10W30 a 10 wt oil with additives that make it "thicken up" to a 30 wt per se,when the straight weight 30 is already a 30 weight from the get go?


Not exactly. A straight-weight oil is not allowed to have viscosity modifiers, or so its been reported here.

However, there's nothing saying that a multi-grade HAS to have a ton of VI improvers. It can simply have a base oil with a higher viscosity index.

Given modern synthetic oils, the difference between a single grade 30 and a 10w30 is probably more a factor of how the manufacturer chose to have the oil rated and marketed, rather than a huge difference the oil itself. But I would not ever assume that a straight-30 group II dino could come anywhere CLOSE to the same thickness as a synthetic 10w30 once you get above the 100c test point.

And even if you're talking about dino 30 compared to dino 10w30, the way the oil degrades when heated is different. The 10w30 will stay thicker for a while at extreme high temperatures, but the VIIs will start to oxidize and break down. The 30 weight will just go thin immediately, but won't break down as much. So, for example in the case of a sudden extreme overheat, the 10w30 might protect better than the 30 because it doesn't turn to water, but its life will be significantly shortened by the event.
 
Originally Posted By: Peter_Pan

Mitsubishi, Chrysler and Toyota are recommending 5W-20 in most (if not all) of their most popular 4 cylinder engines now for a few years.


Chrysler is also recommending 5w20 in their bigger v6 and v8s as well. The 4.7 SOHC is spec'd for 5w20, and so are the 5.7L Hemis, and 5w20 is apparently mandatory- as in the manual has warnings against xw30 oil- for 5.7s with MDS (multi-displacement system, Chrysler's cylinder deactivation scheme). I think the only exception is the 6.1L SRT Hemi.
 
Originally Posted By: 440Magnum
But I would not ever assume that a straight-30 group II dino could come anywhere CLOSE to the same thickness as a synthetic 10w30 once you get above the 100c test point.



I would just like to add a comment regarding the statements about straight 30 and multi-grade 30 over 100C. Just because a straight 30 has no VII's does not necessarily mean that it will be thinner than a multi-grade 30 with VII's at temps higher than 100C (or vice-versa). It totally depends on the properties of the VII's themselves.

The long chain polymers that make up VII's slowly uncoil as the oil is heated to provide an apparent resistance to thinning. However, once the chains have fully openend up and stretched out, they will no longer provide any further resistance to thinning past that temperature.

So, lets say (for purpose of theoretical example) that a straight 30 and a multi-vis 30 both measure 10 cSt at 100C. Let's also say that the VII's have fully uncoiled by 100C. As both oils are heated, the multi-vis will not be thicker than the straight 30 due to no further help from the VII's. But, if the VII's have not fully opened by 100C, then you are correct that the multi-vis oil will continue to thin out less than the straight 30 as temperatures increase.

Also, lets not forget about HTHS. Amsoil's ACD 30 weight HTHS is ~3.5, and that is measured at 150C. Not too many multi-vis 30 weights come close to that, with the obvious exception of GC, Redline, and some other synthetic formulations.

So protection over 100C is not black and white. It's really dependent on the two oils in question rather than a generalization.
 
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I know a guy who own a air cooled vw shop and the only dino oil he says to use is a 30HD oil. He claims that because it dosent have modifyers in it the oil dosent sheer down from the polymer chains breaking. But thats only if your [censored] bent on running dino. He uses like a 5w40 or 20w50 syn in his 69 beetle.
 
Ooooooh I can hardly wait. 350 miles to go on the F150 and less than 900 on the Aerostar. F150 will have the SAE30 by the beginning of May. Aerostar probably mid to late May.
 
Originally Posted By: il_signore97
Originally Posted By: 440Magnum
But I would not ever assume that a straight-30 group II dino could come anywhere CLOSE to the same thickness as a synthetic 10w30 once you get above the 100c test point.



I would just like to add a comment regarding the statements about straight 30 and multi-grade 30 over 100C. Just because a straight 30 has no VII's does not necessarily mean that it will be thinner than a multi-grade 30 with VII's at temps higher than 100C (or vice-versa). It totally depends on the properties of the VII's themselves.



And it also depends on the VI of the base oil, even without VI improvers. You can make an oil with a VI of 90 the same viscosity as an oil with a VI of 150 at any one temperature, but the low VI oil will change thickness as you go cooler *or* hotter a lot faster than the high VI oil.

Originally Posted By: il_signore97
So protection over 100C is not black and white. It's really dependent on the two oils in question rather than a generalization.



We're in violent agreement here. The point I've tried to make whenever this comes up is that when people pull out an SAE 30 that has a similar viscosity to a 10w30 at the cold end, its a fairly exceptional SAE 30 and shouldn't be compared to the uber-generic non-API rated stuff you can get for $.99/quart on the automotive aisle at the supermarket. And also, a synthetic 10w30 today isn't going to be nearly as dependent on VIIs as a 10w30 from 1975 was (and today's VIIs are probably a lot better too), so broadly generalized statements about how quickly multigrades shear down and how "all those VIIs" contribute to sludge and combustion chamber deposits are getting outdated.

So while it may seem that I've only argued one side of this, its only because I'm pointing out how "conventional wisdom" doesn't necessarily apply. The other side is that there *ABSOLUTELY* are single-grade oils that perform as well as many multi-grades now. The only question I have is why the manufacturers don't go ahead and rate them as a multigrade, and I suspect that the reason is they gain some sales from the "conventional wisdom" that single-grade is purer and nobler than multi-grade because single-grade rating doesn't allow VIIs. Personally, I'd love to see every bottle of oil state explicitly what percentage of VIIs it contains. That would remove a lot of mystery.
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The OP spoke of Valvoline so I will look at Valvoline.

The Valvoline straight 30 has a 40C cSt of 86.45, 100C of 11, VI of 114. It would thin to 9.3 cSt, bottom of 30 grade, at 225.2F

Valvoline 10w30 has a 40C cSt of 69.4, 100C cSt of 10.67, VI of 141. It would thin to 9.3 cSt at 223.5F

Valvoline Synpower 10w30 has a 40C cSt of 64, 100C cSt of 10.5, VI of 153. It would thin to 9.3 cSt at 222.4F
 
Originally Posted By: 440Magnum


We're in violent agreement here. The point I've tried to make whenever this comes up is that when people pull out an SAE 30 that has a similar viscosity to a 10w30 at the cold end, its a fairly exceptional SAE 30 and shouldn't be compared to the uber-generic non-API rated stuff you can get for $.99/quart on the automotive aisle at the supermarket. And also, a synthetic 10w30 today isn't going to be nearly as dependent on VIIs as a 10w30 from 1975 was (and today's VIIs are probably a lot better too), so broadly generalized statements about how quickly multigrades shear down and how "all those VIIs" contribute to sludge and combustion chamber deposits are getting outdated.

So while it may seem that I've only argued one side of this, its only because I'm pointing out how "conventional wisdom" doesn't necessarily apply. The other side is that there *ABSOLUTELY* are single-grade oils that perform as well as many multi-grades now. The only question I have is why the manufacturers don't go ahead and rate them as a multigrade, and I suspect that the reason is they gain some sales from the "conventional wisdom" that single-grade is purer and nobler than multi-grade because single-grade rating doesn't allow VIIs. Personally, I'd love to see every bottle of oil state explicitly what percentage of VIIs it contains. That would remove a lot of mystery.
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Very well stated. I couldn't agree more. Now that we've come to this conclusion, it's time for a nice
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FrankN4,

Just to comment on your post... The viscosity you posted for the straight 30 at higher temp will be correct, given the fluid has no VII's. However, using viscosity index to extrapolate for other fluids with VII's (such as valvoline conventional 10W30) will not produce accurate results. VI is measured using 40C and 100C viscosities, and that is the area where the VII's mostly take effect. The actual viscosity index of the fluid AFTER the VII's are done doing there work (after they've fully uncoiled) will become a lot lower. We don't know where this max temperature lies, and it's different for each product, but it is just good to point out that any calculations at high or low temperatures using viscosity index on a fluid fortified with VII's may not be correct.
 
Originally Posted By: il_signore97

FrankN4,

Just to comment on your post... The viscosity you posted for the straight 30 at higher temp will be correct, given the fluid has no VII's. However, using viscosity index to extrapolate for other fluids with VII's (such as valvoline conventional 10W30) will not produce accurate results. VI is measured using 40C and 100C viscosities, and that is the area where the VII's mostly take effect. The actual viscosity index of the fluid AFTER the VII's are done doing there work (after they've fully uncoiled) will become a lot lower. We don't know where this max temperature lies, and it's different for each product, but it is just good to point out that any calculations at high or low temperatures using viscosity index on a fluid fortified with VII's may not be correct.


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I absolutely agree. I am guilty of oversimplifying. I wanted to show that a straight 30 grade(Valvoline claims their mono 30 has no VII)would be less likely to thin as much, turn to water, as a 10w30 multi grade oil. I took the "easy, simple" way and used the VI graph which, as I understand, does not take into account any added VII.(I don't even see how it could given the various types and quality of VII) To be even close to accurate, I would have to get the VI of the Valvoline 10w30 base oil and do a lot of math I am not really interested
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(simple way out) in doing.
 
Originally Posted By: FrankN4
thumbsup2.gif
I absolutely agree. I am guilty of oversimplifying. I wanted to show that a straight 30 grade(Valvoline claims their mono 30 has no VII)would be less likely to thin as much, turn to water, as a 10w30 multi grade oil. I took the "easy, simple" way and used the VI graph which, as I understand, does not take into account any added VII.(I don't even see how it could given the various types and quality of VII) To be even close to accurate, I would have to get the VI of the Valvoline 10w30 base oil and do a lot of math I am not really interested
blush.gif
(simple way out) in doing.




Hey, there's nothing wrong with that approach at all! I just think that a lot of us don't take the time to re-iterate the "basics" since we all take it as common knowledge, but new members may not understand all of these conceps. So I just wanted to clarify for anyone reading that is not up to speed with all of this stuff. I figured you already knew that you were oversimplifying
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Originally Posted By: il_signore97
Originally Posted By: FrankN4
thumbsup2.gif
I absolutely agree. I am guilty of oversimplifying. I wanted to show that a straight 30 grade(Valvoline claims their mono 30 has no VII)would be less likely to thin as much, turn to water, as a 10w30 multi grade oil. I took the "easy, simple" way and used the VI graph which, as I understand, does not take into account any added VII.(I don't even see how it could given the various types and quality of VII) To be even close to accurate, I would have to get the VI of the Valvoline 10w30 base oil and do a lot of math I am not really interested
blush.gif
(simple way out) in doing.




Hey, there's nothing wrong with that approach at all! I just think that a lot of us don't take the time to re-iterate the "basics" since we all take it as common knowledge, but new members may not understand all of these conceps. So I just wanted to clarify for anyone reading that is not up to speed with all of this stuff. I figured you already knew that you were oversimplifying
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If I was going to run a straight weight oil, I would make sure the oil filter had the bypass on the thread end. Likely you are going to see more bypass on cold starts.
 
Originally Posted By: labman
If I was going to run a straight weight oil, I would make sure the oil filter had the bypass on the thread end. Likely you are going to see more bypass on cold starts.
True, but likely less bypass on SAE 30 cold summer starts than on multigrade cold winter starts. Anyway, I always use the threaded end bypass if the spec calls for a filter with a bypass.
 
The SAE 30 went in the 4.9L F150 today with a Baldwin filter:

5 qts Valvoline Premium Conventional straight 30 (760 phos)
1 15 oz bottle CD2 High mileage additive (3600 phos)
5 oz of SLOB (4900 phos)

End result is a brew that has 1100 ppm phosphorus and is 11.9 cSt.
5 qts, 20 oz brings it right to the top of safe zone.

Am figuring a 5000 mile run.
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