M1 EP

[ToyotaNSaturn]

Johnny & buster have given me the M1 bug. Thanks guys!

So both my rides are using some form of M1 products that I had on hand.

AAP's special M1 deal ends today. Went to the local AAP last night. Too bad they only had two bottles of M1 EP 5w30, NONE of the 5w-20 EP, but had plenty of the VII-challenged 10w-30 EP.

Gotta love the iPhone (or any phone with a web browser)...was able to look up the PDS sheets right there in the aisle to make an informed purchase decision.

I was surprised to see that the M1 10w-30 EP had a substantially lower VII number than the 5w-20 EP or 5w30 EP counterparts:

Code:


Type VII number

M1 5w-20 EP 171

M1 5w30 EP 169

M1 10w-30 EP 148


I would think that the Viscosity Index of the 10w-30 would be higher than the other two. Or do I have my thinking backwards on this?

I'm confused....

Please help un-confuse me. Thx...

 

[ARCOgraphite]

Its vi. Typ the bigger the spread from winter service rating to SAE grade the higher the VI. Like a 0w-40 will have a VI over 180 typ. Is that a good thing? Depends on how they got there.
- note: VII is 'viscosity index improver' - a chemical (polymer) additive not a calculation.

 

[ChiTDI]

But to answer his question, a lower vi number indicates less viscosity improver added. Less spread between the two viscosity numbers (10 and 30) indicates less additive needed. IIRC.

 

[d00df00d]

Viscosity index indicates how much the viscosity changes with temp.

High VI = little change
Low VI = more change

Since the 10w-30 is thicker than the 5w30 when cold, it's not surprising that its VI is lower.

Does that make sense?

 

[ToyotaNSaturn]

Ok, thanks. Some how I got it in my brain that the higher the VII number the better. So the lower the better as it means less VII improver added to the mixture. --which mean less volatility...?

 

[d00df00d]

Quick terminology thing:

VI = Viscosity Index
VII = Viscosity Index Improver (something added to the oil specifically to improve VI)

Also a caveat: I'm sure there is a LOT more to this, so hopefully someone better informed can chime in. Here's what I have learned.


A higher VI is a good thing, all else equal. If the oil's viscosity doesn't change as much with temp, that usually means it won't thin out as much in the really hot spots in your engine. It also means the oil won't thicken up as much when cold, which is a good thing for cold starts.

However, if that high VI is achieved with lots of VIIs, you might not want it for a hard-driven or turbocharged engine because some VIIs can break down. It's not about volatility per se; it's more about deposit formation and whether the oil will retain its characteristics over its lifetime. VII breakdown can leave deposits and cause the oil's viscosity characteristics to change.

Keep in mind that not all oils need VIIs to get whatever VIs they have. Some of them, especially synthetics, are just fine on their own. I know Red Line always bragged about not using any VIIs in any of their oils except the very few with really ambitious grades (5w-40, 0w-40, etc.). It all depends on the formulation.

However, higher VI does usually mean higher volatility, all else equal. It could be due to VIIs, or just the fact that higher VI base stocks are usually more volatile on their own.

In other words, oils with smaller VIs are usually "tougher", i.e. they can take more of a beating and still perform. The question is whether this advantage is worth the poorer viscosity retention. That depends on the car, the oil, the usage, and individual preference.

 

[Tom NJ]

Absolutely perfect post, with one small exception.

Originally Posted By: d00df00d
However, higher VI does usually mean higher volatility, all else equal. It could be due to VIIs, or just the fact that higher VI base stocks are usually more volatile on their own.


Higher VI base stocks generally have lower volatility (e.g. PAOs, esters, Grp IIIs). If higher VI oils tend to have higher volatility (depends on the formula) it is probably due to the use of lighter (thinner) base stocks to make the wide viscosity grade. Wide grade oils need a lighter base stock to make the low W grade, and more VII to make the high temperature grade. For example, a 0W-40 oil uses a lighter base oil than a 10W-40 oil and so may have a higher volatility, and it will also have a higher VI due to the use of more VII. If, however, the 0W-40 uses a PAO base stock and the 10W-40 uses a Grp I or II base stock, then the 0W-40 may have lower volatiltiy than the 10W-40.

Tom NJ

 

[Steve S]

Seems the base oils VI is what should be looked at?

 

[Johnny]

My question is, when we see a spec sheet on an oil, any brand, and we see a VI (viscosity index) of lets say 155, or any number you want to pick, that does not tell us how they achieved the VI, does it? I mean we don't know if it was the base stock that did it, or the VII that did it, correct?

 

[Schmoe]

Man, you guys are WAYYYY over my head. ToyotaNSat....do what I do....just take the plunge and run everything, I mean EVERYTHING on one oil. Now, I'm talking M1EP stuff here. I use M1EP 5w30 on everything below to include my boat, lawnmower, generator and power washer, all 4 stroke engines of course. Well, let me back up, I use about 50/50 5W and 10W on the truck, I'm still in the thicker is better for big V8 engines....The Accord I sold had an exclusive diet of nothing but M1EP 5w30 and the inside of the engine was still looking like it just got out of the factory, and that with all those miles on it. If it wasn't for the transmission worry, I'd have kept it. Especially now that the wife does NOT like the CRV. Something about going from a V6 back to a 4 banger just eats her lunch, even though that 4 banger almost has as much HP as her old Accord...

 

[d00df00d]

Originally Posted By: Tom NJ
Higher VI base stocks generally have lower volatility (e.g. PAOs, esters, Grp IIIs). If higher VI oils tend to have higher volatility (depends on the formula) it is probably due to the use of lighter (thinner) base stocks to make the wide viscosity grade. Wide grade oils need a lighter base stock to make the low W grade, and more VII to make the high temperature grade. For example, a 0W-40 oil uses a lighter base oil than a 10W-40 oil and so may have a higher volatility, and it will also have a higher VI due to the use of more VII. If, however, the 0W-40 uses a PAO base stock and the 10W-40 uses a Grp I or II base stock, then the 0W-40 may have lower volatiltiy than the 10W-40.

Tom, thanks again for the detailed correction. Your input is appreciated as always.

 

[ToyotaNSaturn]

great info guys!

Johnny, your question...Would it be safe to have reasonable assumption that oils such as M1 10w-30 don't need VII as thee base stock and the technology behind it provide the "muscle" to meet the necessary spec's w/o much, if any, VII added as there is little spread to the two numbers? We're not talking Group II oils here...Group III and probably Group IV so it wouldn't seem like a stretch to me if there were little or no VII added to the 10w-30 product.

 

[Johnny]

Not sure, that's why I asked the question. Some on here are going crazy about the Toyota and Honda 0W-20 oil VI of over 200. How do they come up with that number, base stock, or VII?

 

[d00df00d]

AFAIK -- and hope Tom is still here to confirm or correct:

- If you see a high VI in combination with a low HTHS, low flash point, or high volatility compared to similar oils with similar kinematic viscosity specs, that's good reason to suspect high VII content.

- It's easily possible for a synthetic oil (anything group III or higher) to have a VI over 140 with no VIIs.

 

[Tom NJ]

Originally Posted By: d00df00d
AFAIK -- and hope Tom is still here to confirm or correct:

- If you see a high VI in combination with a low HTHS, low flash point, or high volatility compared to similar oils with similar kinematic viscosity specs, that's good reason to suspect high VII content.


Generally yes, either a higher VII content or a highly efficient VII (shear instable). The low HTHS & FP along with the high volatility indicate a lighter base oil was used and therefore requires more thickening to make the grade. By itself the VI is virtually useless information since, as Johnny noted, you do not know how they achieved it.

Originally Posted By: d00df00d
- It's easily possible for a synthetic oil (anything group III or higher) to have a VI over 140 with no VIIs.


The VIs of most synthetic base oils are under 140 (PAO 4 120s, PAO 6 130s, esters 130-150, AN-5 70s, Grp IIIs 120-140). Some additives may raise the VI and some may lower it. Yes you can achieve a VI 140 without VIIs, but the cost would generally be higher if you needed to add esters or PAO 100.

Tom NJ

 

[tig1]

Originally Posted By: Schmoe
Man, you guys are WAYYYY over my head. ToyotaNSat....do what I do....just take the plunge and run everything, I mean EVERYTHING on one oil. Now, I'm talking M1EP stuff here. I use M1EP 5w30 on everything below to include my boat, lawnmower, generator and power washer, all 4 stroke engines of course. Well, let me back up, I use about 50/50 5W and 10W on the truck, I'm still in the thicker is better for big V8 engines....The Accord I sold had an exclusive diet of nothing but M1EP 5w30 and the inside of the engine was still looking like it just got out of the factory, and that with all those miles on it. If it wasn't for the transmission worry, I'd have kept it. Especially now that the wife does NOT like the CRV. Something about going from a V6 back to a 4 banger just eats her lunch, even though that 4 banger almost has as much HP as her old Accord...


The M1 EP oils have performed very well for me also. Engines seem as clean as new even after many miles.

 

[ToyotaNSaturn]

Originally Posted By: Johnny
Not sure, that's why I asked the question. Some on here are going crazy about the Toyota and Honda 0W-20 oil VI of over 200. How do they come up with that number, base stock, or VII?


I agree...it don't understand the Toyota 0w-20 frenzy either. just because it's a high VII doesn't mean the oil is worth chasing after. I'm thinking a lower VII would be desirable as there would be lower volatility (do i have this right?).

PZ HM 20w-50 has a VII of 130 and a Noack Vol of 5.0. Can't get better than that (right?)...problem is that the oil is too thick for my applications at least.