Good cold flow

[ZeeOSix]

I wish there was a KV-zero- reporting requirement, KV40 is still over 100 deg F test. I suppose the data could be extrapolated, but with high VM loads I would think it's hard to predict.

That's what the "W" rating if for. Who's going to be able to tell which oil to use in cold weather if they just see a zero or subzero KV number?

Plus many blenders are not particularly forthcoming with KV40 or VI.

Pretty much every spec sheet I've seen from main brand oil makers show KV40, KV100 and VI. Noack and HTHS are the specs that not all makers show.

 

[Accent Abuser]

*Besides the lower cranking ability and opportunity for more PAO content of the 0W20 oils - I would not necessarily rule out 5W20 synthetic oils for usage . For one , they usually have a lower NOACK than a 0W20 as well as usually more shear stable as well . For GDI engine applications a 5W20 synthetic oil may have benefits (unless you live in a truly frigid climate) .

And for some GDI or TGDI applications, an xW-30 or xW-40 is better, even if the engine calls for 20 (Hyundai/Kia especially). I say this all the time here but the only reason one should use a 20 grade is if their goal is the absolute best fuel economy or if all they do is very short trips during the winter (and even then a 30 would likely be fine). With that in mind, a 0w-20 has a very small fuel economy advantage over 5w-20 due to not only easier warm-up flow, but lower friction overall because many 0w-20s rely heavily on friction modifiers, which, aside from the counterintuitive fact that zddp increases friction, is why they can get away with lower zddp levels you see in oils like M1 AFE.

Regarding start-up flow, most anybody in the lower 48 states could easily get away with a 5w or even 10w (down to 0°F) during winter, but you will get better fuel economy from a 0w.

 

[Accent Abuser]

A SAE J300 grade is not a "better oil", I would compare finished lubricants.
So what two were you thinking of?

I just looked at Valvoline HM syn , and I would pick the 0W20 if expecting a nasty, cold winter. Just due to the higher VI and lower KV40.

I wish there was a KV-zero- reporting requirement, KV40 is still over 100 deg F test. I suppose the data could be extrapolated, but with high VM loads I would think it's hard to predict. Plus many blenders are not particularly forthcoming with KV40 or VI.

I would just like to note the OP did not mention "synthetic". Maybe they are interested in a "conventional" 5W20

True it does have a lower KV40, but KV40 does not translate into pumpability or start ability at temps where it matters (ie 0 degrees). A 0w40 is twice as viscous as a 0w20 at 40°C but at -35°C, both will be equally pumpable, and if it can be pumped at -35, it can be pumped at any temperature above that. A 0w20 will flow more easily and produce less drag, especially during warm up, giving better fuel economy.

 

[PimTac]

And for some GDI or TGDI applications, an xW-30 or xW-40 is better, even if the engine calls for 20 (Hyundai/Kia especially). I say this all the time here but the only reason one should use a 20 grade is if their goal is the absolute best fuel economy or if all they do is very short trips during the winter (and even then a 30 would likely be fine). With that in mind, a 0w-20 has a very small fuel economy advantage over 5w-20 due to not only easier warm-up flow, but lower friction overall because many 0w-20s rely heavily on friction modifiers, which, aside from the counterintuitive fact that zddp increases friction, is why they can get away with lower zddp levels you see in oils like M1 AFE.

Regarding start-up flow, most anybody in the lower 48 states could easily get away with a 5w or even 10w (down to 0°F) during winter, but you will get better fuel economy from a 0w.

Huh?

 

[Snagglefoot]

View attachment 74884
5W is good down to -30C, 0W down to -35C. How cold temperatures do you see?

Where I live we usually see at coldest -25C. So I’m totally happy with 5W oil.

Not that it’s a big deal but most motor oils will have a low temperature pumping viscosity lower than the 60,000 cP requirement at the respective temp and will vary by brand with the same grades.

 

[ARCOgraphite]

That's what the "W" rating if for. Who's going to be able to tell which oil to use in cold weather if they just see a zero or subzero KV number?


Pretty much every spec sheet I've seen from main brand oil makers show KV40, KV100 and VI. Noack and HTHS are the specs that not all makers show.

I never push the gell point; I wouldn't venture out of the house at -30 or -35 C.

Most people asking about a good "cold flow" are likely curios about performance from
1 deg F up to freezing. That why I mentioned a KV -0- datapoint.

I have NOT seen VI reported lately from XoM but have from BP. True on the KV40, but I was recently looking at an M1 EP datasheet and KV40 was oddly missing - though the row was there - it was not populated.

 

[Snagglefoot]

I never push the gell point; I wouldn't venture out of the house at -30 or -35 C.

Most people asking about a good "cold flow" are likely curios about performance from
1 deg F up to freezing. That why I mentioned a KV -0- datapoint.

I have NOT seen VI reported lately from XoM but have from BP. True on the KV40, but I was recently looking at an M1 EP datasheet and KV40 was oddly missing - though the row was there - it was not populated.

Here is a theoretical calculation of viscosities of various grades down to 0 degrees C and also the spec sheets showing the CCS viscosity of Pennzoil Platinum Euro 0w40 and Pennzoil Platinum 0w20. The CCS Viscosity at -35C are similar for all intents and purposes but are not identical. Also shown are the KV 40 numbers. Enjoy.

 

[Snagglefoot]

Here is a good website to look at temperatures at your location in the past.

We hit -15 F this past winter. I was running 0w30 and had an 8 hr cold soak. I used to run 5w30 year round but now I run 0w30 in the winter. 5w30 does fine but 0w30 is available. You need to experience it in person to see why you might want to use 0w30 even if it’s only -15 F.