straight 30 weight vs 10w 30

[supercity]

Originally Posted By: CATERHAM
Originally Posted By: lubedude13
Briggs currently specs synthetic 5w30

That could be a very interesting motor oil.
We have a VOA on the Briggs 30wt and it is a light 30 grade (KV100 of 10cSt) but it has the high phos level (1,000 ppm IIRC).
So if their 5W-30 synthetic has the same high phos level it would be an interesting lighter option to running a heavier 10W-30 HDEO.
I'd like to see a VOA on it just to confirm.


If you want a synthetic light 30 grade with high phos look for an ACEA A5/B5 or something Ford WSS-M2C-913 approved.

 

[yvon_la]

carefull to buy the proper sae 30 oil there are some proper and other that are for other use

 

[userfriendly]

Mono grades are the industrial work horses. I use them all the time, in fact my 2011 Duramax has SAE 40 in it right now. When the oil reaches 10K miles (16K Km) I'll pull a sample and see how everything is holding up. The oil has a 100C advertised vis of 14.6 but the oil pressure is higher all the time than that of a 15.6 15W40. The oil pressure VS warm-up curve is quite a bit higher than any brand of 15W40 I used in the past. The OC flash point is 265C so it is likely the evaporation losses will low enough that I may actually gain on the dipstick as the oil gathers dust, rocks, birds, small children, and the 1/2 inch socket I can't find. As a rule of thumb, I have found that when a single grade engine oil is used, I can drop one grade, example from a 15W40 to an SAE30 and see about the same oil pressure most of the time. High oil pressure is a result of resistance to flow, the latter being more important. I doubt if the oil temperature in the Duramax ever gets anywhere near 100C. The viscosity at the temperature the engine oil operates at is the important value.

 

[Shannow]

Originally Posted By: used_0il
The oil has a 100C advertised vis of 14.6 but the oil pressure is higher all the time than that of a 15.6 15W40. The oil pressure VS warm-up curve is quite a bit higher than any brand of 15W40 I used in the past. The OC flash point is 265C so it is likely the evaporation losses will low enough that I may actually gain on the dipstick as the oil gathers dust, rocks, birds, small children, and the 1/2 inch socket I can't find. As a rule of thumb, I have found that when a single grade engine oil is used, I can drop one grade, example from a 15W40 to an SAE30 and see about the same oil pressure most of the time.


That's because your SAE 40 is actually a 40 grade and is a Newtonian fluid...

As such, its HTHS is going to be inherently that which a Newtonian (straight) 40 provides, somewhere well North of 4.

The 15W-40, being a non-Newtonian multigrade will always have a lower HTHS and film thickness than the actual 40 grade...the reason that the HTHS minimums were introduced to J300, to prevent multigrades that had too much temporary shear being sold to people expecting traditional protection.

Like an SAE 30 SHOULD have an HTHS around 3.4-3.6, because that is the HTHS that is normal for an SAE30...and is also typical of a 15W-40 multigrade.

 

[userfriendly]

Being pragmatic and all that, I wouldn't dare use the word always. I always went to the same bar in my home town for a beer and the same 10 people were always there sitting on the same stools, always telling the same stories for 20 years. They always drank the same brand of beer and always smoked the same brand of cigarettes. I always knew what they were going to say before they said it like "When did you get out of prison?". The last time I went there the place was cleaned up, the people were dressed better, new tables and chairs, but nobody I knew. When two of the guys got up and started dancing together, that is when I left. Before that day I always took at least a minute to down a beer, not 7 seconds, and now I always look around before ordering a drink. The SAE 40 I'm using has a HTHS of 4.2 and the 15W40 I was using 4.4 period.

 

[Shannow]

Fair cop...

 

[Hyde244]

A straight 30 weight oil is 30 weight both when it is cold (that is, at the start-up of the motor) and hot (when the motor has reached operating temperatures). 10w30 weight oil is 10 weight when cold, and 30 weight when hot. The advantage of doing this is easier starting of an engine in colder temperatures.

In order for 10w30 to achieve this, viscosity improvers (VIs) must be added to make the oil act differently. These VIs can sheer more easily than the base stock oil, which is where the reasoning comes for 10w30 not being as sheer resistant as 30 weight.

Today, 30 weight oil is really only found as recommendation for air-cooled push lawn mowers, such as my own Briggs and Stratton 4 HP mower. Since the mower is only operated in the summer, the engine does not need a lower viscosity to start, and the 30 weight oil is more sheer resistant throughout the season. However honestly, I just throw in whatever extra oil I have, such as the Edge 5w30 that is in the power at present.

 

[gfh77665]

Originally Posted By: Hyde244
...is only operated in the summer, the engine does not need a lower viscosity to start, and the 30 weight oil is more sheer resistant throughout the season.


Thats also why SAE 30 will work great during the summer for cars and trucks in the southern half of the US. When the low temp overnight is 80 degrees, the "5" part of 5-XX never comes into play.

 

[kschachn]

Can you explain what you mean by "works great"? I mean it will work, but great?

I guess my real question is why? Why would you use straight-weight oil when there are clear and obvious advantages to multi-grade, even in warmer climates. To me it seems like "just because you can" is the reason most people do it.

Originally Posted By: gfh77665

Thats also why SAE 30 will work great during the summer for cars and trucks in the southern half of the US. When the low temp overnight is 80 degrees, the "5" part of 5-XX never comes into play.

 

[gfh77665]

You got questions, I have answers.

Works great? YES. I did a 7500 mile run on it and it did not consume like a 5-30 would have, I never had to add any oil.

Why? I got a boatload of PYB SAE 30 almost free.

 

[kschachn]

Well yeah, I knew you got a lot for a low price, I remember that post. But still. None of my cars consume any abnormal amounts of 5W-30 neither, nor do they drink a lot of 0W-20 or 5W-20.

Oil consumption when within "normal" limits isn't my first criteria when choosing an oil.

Originally Posted By: gfh77665
You got questions, I have answers.

Works great? YES. I did a 7500 mile run on it and it did not consume like a 5-30 would have, I never had to add any oil.

Why? I got a boatload of PYB SAE 30 almost free.

 

[gfh77665]

My cars don't consume an abnormal amount, either, nor is that my choosing criteria. Regardless, less consumption is even better!

 

[yvon_la]

A single-grade engine oil, as defined by SAE J300, cannot use a polymeric Viscosity Index Improver (also referred to as Viscosity Modifier) additive. SAE J300 has established eleven viscosity grades, of which six are considered Winter-grades and given a W designation. The 11 viscosity grades are 0W, 5W, 10W, 15W, 20W, 25W, 20, 30, 40, 50, and 60. These numbers are often referred to as the "weight" of a motor oil, and single-grade motor oils are often called "straight-weight" oils.

For single winter grade oils, the dynamic viscosity is measured at different cold temperatures, specified in J300 depending on the viscosity grade, in units of mPa·s, or the equivalent older non-SI units, centipoise (abbreviated cP), using two different test methods. They are the Cold Cranking Simulator (ASTMD5293) and the Mini-Rotary Viscometer (ASTM D4684). Based on the coldest temperature the oil passes at, that oil is graded as SAE viscosity grade 0W, 5W, 10W, 15W, 20W, or 25W. The lower the viscosity grade, the lower the temperature the oil can pass. For example, if an oil passes at the specifications for 10W and 5W, but fails for 0W, then that oil must be labeled as an SAE 5W. That oil cannot be labeled as either 0W or 10W.

For single non-winter grade oils, the kinematic viscosity is measured at a temperature of 100 °C (212 °F) in units of mm2/s (millimeter squared per second) or the equivalent older non-SI units, centistokes (abbreviated cSt). Based on the range of viscosity the oil falls in at that temperature, the oil is graded as SAE viscosity grade 20, 30, 40, 50, or 60. In addition, for SAE grades 20, 30, and 1000, a minimum viscosity measured at 150 °C (302 °F) and at a high-shear rate is also required. The higher the viscosity, the higher the SAE viscosity grade is.
http://en.wikipedia.org/wiki/Motor_oil#Single-grade

 

[lilrobo]

i dont understand
i was told that 10w 40 is 40 cold and 10 hot .. i bought SAE 30 penn, of that is the case 40 hot is better than 30 hot no?? i did but a better gauge i should be able to tell now

 

[KrisZ]

Originally Posted By: gfh77665
Thats also why SAE 30 will work great during the summer for cars and trucks in the southern half of the US. When the low temp overnight is 80 degrees, the "5" part of 5-XX never comes into play.



It always comes into play. Now, wether it affects the engine in any negative way, that is a totally different argument, but oil's viscosity always changes with the temperature. So, if an oil has a thinner startup viscosity it will always be thinner at startup temps, no matter if it's -30F or 100F outside.

 

[Hyde244]

Originally Posted By: gfh77665
Thats also why SAE 30 will work great during the summer for cars and trucks in the southern half of the US. When the low temp overnight is 80 degrees, the "5" part of 5-XX never comes into play.
+1 Very true. A simple visual inspection of how easily 30w and 5w30 oil flows in the bottle can show that viscosity does not matter as much at summer temperatures.

All of which is to arguably say, it is the additive package of name brand oils that makes them attractive in warm operating climates - not the actual multi-viscosity components.

Of course living in Ohio, we can have all four season in a day, so having that 5w30 can still be helpful.

 

[Clevy]

Originally Posted By: Hyde244
A straight 30 weight oil is 30 weight both when it is cold (that is, at the start-up of the motor) and hot (when the motor has reached operating temperatures). 10w30 weight oil is 10 weight when cold, and 30 weight when hot. The advantage of doing this is easier starting of an engine in colder temperatures.

In order for 10w30 to achieve this, viscosity improvers (VIs) must be added to make the oil act differently. These VIs can sheer more easily than the base stock oil, which is where the reasoning comes for 10w30 not being as sheer resistant as 30 weight.

Today, 30 weight oil is really only found as recommendation for air-cooled push lawn mowers, such as my own Briggs and Stratton 4 HP mower. Since the mower is only operated in the summer, the engine does not need a lower viscosity to start, and the 30 weight oil is more sheer resistant throughout the season. However honestly, I just throw in whatever extra oil I have, such as the Edge 5w30 that is in the power at present.



Some brands of 10w-30 use no viscosity index improvers whatsoever,so your incorrect in your blanket statement.

Originally Posted By: lilrobo
i dont understand
i was told that 10w 40 is 40 cold and 10 hot .. i bought SAE 30 penn, of that is the case 40 hot is better than 30 hot no?? i did but a better gauge i should be able to tell now




You've got it backwards.
The W in 10w-40 for example stands for winter,not weight. And the first number,in this case 10 represents the cold or winter viscosity,and the 40 represents the viscosity at operating temp.
So a 10w-40 is thinner when cold vs an sae40 however at operating temp they are the same.
Another example would be in the 30 grade variant. A 0w-30 is thinner when cold vs a 5w-30 and thinner than a 10w-30,however all 3 are consistent when the oil reaches operating temp.
There was a time when I searched out 10w-30 grades for use in the summer,then changed to a 5w-30 or 0w-30 for winter.
Today I'm less interested in changing grades for the changing seasons.
Of course if I can find a 10w-30 cheaper than the others I'll use it in the summer but it depends on what I've got in my stockpile. If I've got ample 0w/5w-xx in my stash I'm not going to pay full price for a 10w-xx just to have it for summer,but again if I find a sale I'll use it.
Today's oils are fantastic and changing grades based on the season is less important when compared to 20 years ago,and today's offerings are less likely to contribute to the deposits they once did,which was a contributor to sludge and engine death.
If I lived in a climate where it was always warm I'd use whatever 10w/15w worked for my coldest temps. Less/no viscosity index improvers appeals to me,but it's in no way a deal breaker.

 

[OVERKILL]

Originally Posted By: Hyde244
A straight 30 weight oil is 30 weight both when it is cold (that is, at the start-up of the motor) and hot (when the motor has reached operating temperatures). 10w30 weight oil is 10 weight when cold, and 30 weight when hot. The advantage of doing this is easier starting of an engine in colder temperatures.


No, a 10w-30 simply meets the performance requirements (low temp performance) to satisfy the SAE 10W designation. This doesn't mean it is a 10 weight when cold.

Quote:
In order for 10w30 to achieve this, viscosity improvers (VIs) must be added to make the oil act differently. These VIs can sheer more easily than the base stock oil, which is where the reasoning comes for 10w30 not being as sheer resistant as 30 weight.


There are numerous 10w-30's with little to no VII's. Notable examples are Redline and AMSOIL's 10w-30 oils which use no VII's whatsoever. The base stocks alone are able to satisfy the requirements to obtain the 10W performance designation.

 

[userfriendly]

The opposite way of looking at a 10W30 is that it is an SAE 30 engine oil that passes the cold cranking, cold flow and pumping requirements for a 10W winter grade classification. What is an SAE 30 engine oil? It is an oil that falls between the maximum and minimum 100C viscosity and minimum high temperature hot shear for an SAE30, but it does not carry a winter rating or is tested for a winter rating. To state that an SAE multi grade 10W30 is an SAE 10W that is as thick at 100C as an SAE 30 with a corresponding HTHS minimum is what opposite is to me. The use of additives to allow an SAE 30 to pass the 10W winter rating is not necessarily needed when a high VI base stock is used, taking the Newtonian argument out of the picture. The surprising fact that I can't get my head around is that this site is at least 12 years old, and these basic facts of oil classifications are being being discussed by some of the original members. (Who obviously have not learned a thing, but have post counts into the tens of thousands)

 

[userfriendly]

The edit time out got me. The 1st sentence should read; The proper way of looking at an SAE 10W30 engine oil is that it is an SAE 30 engine oil that passes the cold flow, cold cranking and pumping requirements to pass a winter rating (W) of 10W.