Monograde oils

[oilpan49]

The impressions I get with monograde oils based upon reading my book by James Fitch "How to select a motor oil and filter" Monograde under some given circumstances give better protection and lubricity for the engine. Here is my own opinion based comparison between monograde and multi-viscosity.

Monograde:

Pros:
Extremely shear stable
film strength
Also meet modern day requirements

Cons:
MPG sacrifice
not good for cold weather start up (unless preheated)
not choice grade of oils by most consumers

Multi-viscosity:

Pros:
MPG increase over monograde
start up protection in cold weather
choice grade of oils by consumers and pros.

Cons:
will shear regardless
more expensive to make
????????????????

Bottom line. I'm one of those guys who is not willing to sacrifice lubrication for MPG increase. Maybe next summer, I'll run a SAE 30wt and go to 5w30 in the winter. Just thought I would share what I know,,,,,AR

 

[Gurkha]

Good post, I too have felt the same, however, quality mono-grade HDEO is hard to find, like in the case of Delo 400 SAE 40 or Delvac 1340 SAE 40, no one stocks them anymore and are reluctant to special order them due to economic reasons.

My take is that in a country like India in summers, unless one is going north-wards, SAE 40 makes the best sense and in winters it would be SAE 30.

 

[bruce381]

I can tell you that in a gearbox using a Multigrade gear oil made with a shear stable motor oil type VII the gears will only "see" the base oil, the VII has minimal effect on wear protection and if the Base oil before adding the VII is to thin for the application then gear wear will occur regardless of final viscocity of the gear oil.

Now using a high VIS PAO is another story they work well.
Bruce

 

[Big O Dave]

This is very interesting stuff! I've noticed that with Chevron Delo (as an example, but not limited to this brand) uses "IsoSyn" (hydrocracked) basestock with their multi-viscosity oils, whereas they use solvent-refined basestock with their monogrades.

As I remember reading a few years ago, solvent-refined basestocks contain as much as 20% aromatics and other impurities that perform no lubricating function whatsoever. This is compared to hydrocracked basestocks, which only contain less than 1% non-lubricant impurities, with Group III hydrocracked containing essentially no impurities.

Given that the above is true (and I'm sure someone will correct me

if I'm wrong), it would seem that such oils would have the potential to leave more deposits inside an engine. It would also seem that solvent-refined oil would not lubricate as well as hydrocracked oil because of the higher levels of impurities, which perform no useful purpose, and indeed, at least part of the additive package is there solely to compensate for and address these impurities, as opposed to performing some useful purpose within the engine.

So, to sum what I'm trying to say up, I would be less hesitant to use monograde oils IF they used better basestocks.

If I am wrong in my understanding of the problems with solvent-refined (and monograde) oils, PLEASE correct me!

 

[bruce381]

GP 1 will have better inherent solvency and deposit cleaning effect aswell as good DI package solubility compared to GP III which is the ISOSYN.

Gp 1 also possibly would have better lubricity due to higher sulfur but not a big difference the GP II and III have much higher VI and HTHS numbers which I think offer more bang for the buck.

I think mono grades are considered out of style and as such may be the last in a product line to be upgraded as far a base stocks used. Also the GPII and GP III base oils require a different or
more compatible DI Package due to bad additive solubility. This makes a GPII and GPIII oils more exspensive and the OLD mongrades are more the cheap line.
And remember a 30WT mono grade is really a 30W/30 Multi grade LOL.
Bruce

 

[widman]

Group I base oils can be over 30% aromatics, and VI can be really low, requiring more polymers. The less polimers, the better, but I wouldn't go to the monograde.
I've got hundreds of analisis that show Delo and other group II products with more than 500 hours in tractor and harvester engines without shearing. I've got a power generation company running 800 to 1000 hours on Delo 15w40 remaingin in grade, where they had problems with monograde Group I products at 500 hours. Ambient temps from 21C to 45C. Obviously this is not apples to apples, but they won't go back to 40wt monograde.

 

[TallPaul]

What puzzles me in the Fitch book (page 15) is the list of reasons NOT to use a monograde oil. Reason #4 is "Do not use a monograde if .... it is possible [your] engine might oveheat."

This seems totally opposite of what one would expect. I can only figure that above the normal operating temperature the multigrade thins less than a monograde and therefore may offer more protection.

 

[Ugly3]

The shear stability of multi-grade oils has improved substantially in the past few years. Giving up cold start advantages for a small benefit is shear stability is foolish in my judgment.

 

[DR Racing]

The cold start ability of mono oil's have also improved greatly over the years. Chevron supreme sae 30 has a 108 VI and a pour point of -27 F. As long as temps don't go below 70 F the cold start performance of this will be almost as good as a multigrade. Great summer oil. Dan

[ July 03, 2005, 04:21 PM: Message edited by: DR Racing ]

 

[sgtgeek]

Still many a gearhead at the track and on the street running straight Pennzoil 40...and swearing by it.....

 

[TallPaul]

quote:

---

Originally posted by bruce381:
And remember a 30WT mono grade is really a 30W/30 Multi grade LOL.
Bruce

---

I am not sure this is true for all monograde 30 weights. I suspect that a lot of Monograde 30 weight oils could actually pass the criteria for being a 20w30.

 

[bruce381]

you maybe right new GpII base stocks are sneaking in and they can be 20/30 but old GP I even with a pour depressant can not go that low especially higher 40 and 50 grades that use bright stock.
bruce

 

[Curious Kid]

Quote:
---------
"Still many a gearhead at the track and on the street running straight Pennzoil 40...and swearing by it....."
---------

That may be, but how many have UAO's to back them up? On the other hand, I've loved to be working on my ride from time to time.

In reading about how a straight weight oil wouldn't be recommended where conditions for overheating might exist, I though it a slap-in-the-face of logic, but one must mind VI's I suppose.

Right now I'm working on reading, "Lubrication Fundamentals."

The world of lubrication...facinating.

 

[ediamiam]

my last oil change on my nissan frontier - I usually use chevron 5w30, about 3 1/2 qts, but was 1 qt short and substituted 1 qt of chevron 30 wt instead. Everything seems normal, no sluggishness noticed. Current daytime temp in the area is 90-100. This was kind of a 1 time thing, and don't plan on doing it again, don't see any benefit, or any detriments.

 

[TallPaul]

quote:

---

Originally posted by ediamiam:
my last oil change on my nissan frontier - I usually use chevron 5w30, about 3 1/2 qts, but was 1 qt short and substituted 1 qt of chevron 30 wt instead.

---

You certainly ended up with a thicker base oil in your brew, a 10w30 or perhaps even pushing a 15w30. I have done this type of brew also (1 mono 40 with 5 10w40) and noticed no detrimental effect. Of course it was not winter.

 

[sands]

My owners manual says it's o.k. to use single grade in hot weather...Once the tempuratures fall below 20 degrees it recommends 5W30.

A single grade 30W, 15W40, 15W50, and 20W50 are o.k for warm weather use.

Below 20 degrees only 5w30's or 10W30's.


My manual specifically states that hot weather may require a heavier oil so the motor will get adequate lubrication...And that light weights can provide better gas mileage and extreme cold starting.

Alot of people like thin oils on these forums but in the 100 degree heat combined with blacktop heat retaining pavement(probably 150 degrees plus) that we get down here in Texas I'm running the heavy stuff.

Changed the oil in my sisters car the other day that was running 5W30 and it was like black water in this heat.

 

[Bryanccfshr]

I'll stick with 0w30 for the heat. thanks but no thanks to monograde.

 

[Blue99]

quote:

---

Alot of people like thin oils on these forums but in the 100 degree heat combined with blacktop heat retaining pavement(probably 150 degrees plus) that we get down here in Texas I'm running the heavy stuff.

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Yes, the temperature 10-12" above the pavement surface definetly has an effect on the temp in the oil sump!

Some here will contend that a 5w30 is necessary for start-up wear in all vehicles, in all regions of the country.

With the smokin' hot temps of Texas, in the summertime, my vote is for at least 10W-30 and the straight weight 30's. These oils have lower Noack volatility and the longer hydrocarbon chains, typical in these oils, have better heat resistance.

 

[Ugly3]

quote:

---

Originally posted by sands:
My owners manual says it's o.k. to use single grade in hot weather...Once the tempuratures fall below 20 degrees it recommends 5W30.

A single grade 30W, 15W40, 15W50, and 20W50 are o.k for warm weather use.

Below 20 degrees only 5w30's or 10W30's.


My manual specifically states that hot weather may require a heavier oil so the motor will get adequate lubrication...And that light weights can provide better gas mileage and extreme cold starting.

Alot of people like thin oils on these forums but in the 100 degree heat combined with blacktop heat retaining pavement(probably 150 degrees plus) that we get down here in Texas I'm running the heavy stuff.

Changed the oil in my sisters car the other day that was running 5W30 and it was like black water in this heat.

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Your operating temps will not vary 10 degrees summer to winter. All this concern about hot weather is overblown. Now go racing or pulling a 5,000 pound trailer and it is a different case.

 

[Bryanccfshr]

quote:

---

Originally posted by Ugly3:

quote:

---

Originally posted by sands:
My owners manual says it's o.k. to use single grade in hot weather...Once the tempuratures fall below 20 degrees it recommends 5W30.

A single grade 30W, 15W40, 15W50, and 20W50 are o.k for warm weather use.

Below 20 degrees only 5w30's or 10W30's.


My manual specifically states that hot weather may require a heavier oil so the motor will get adequate lubrication...And that light weights can provide better gas mileage and extreme cold starting.

Alot of people like thin oils on these forums but in the 100 degree heat combined with blacktop heat retaining pavement(probably 150 degrees plus) that we get down here in Texas I'm running the heavy stuff.

Changed the oil in my sisters car the other day that was running 5W30 and it was like black water in this heat.

---

Your operating temps will not vary 10 degrees summer to winter. All this concern about hot weather is overblown. Now go racing or pulling a 5,000 pound trailer and it is a different case.

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Agreed.. Unless the driving requires pulling 80-100% throttle for long periods of time the oil temp is going to stay within 10-15% of the coolant temp. This is regardsless of ambient in a modern ICE with a properly designed factory cooling system.
That and the fact that a multi grade thins less at temps above 100c than a mono grade make it great oil for a lawn mower.
Another issue is oils behavior, run a thicker oil and it runs hotter(thus thinning) run a thinner oil it runs cooler thus being thicker than rated. I think equilibrium is met at certain grades for certain engines.

Happy 4th.