Benefits of 0W

[Astro14]

Been researching oil for a few months now, starting to get the terminology etc.

I am trying to understand if there are any drawbacks to using a 0W oil if climate isn’t really a factor (I am in Florida where it’s almost always above 40°F).

My understanding is that 0W..

1. Better for cold starts (irrespective of ambient air temperature)
2. Better for cold climates (offers “better” protection for ambient temps -40°F to -13°F (-40°C to -25°C))
3. More fuel efficient (for both cold starts or cold climates, irrespective of operating temperature viscosity)

Can the claims above be applied across the board?

I haven’t read much of a downside to 0W, but am wondering..

1. In a multigrade oil, does the delta in grade for cold vs hot matter? For example, the difference in cold/hot between a 0w40 is greater than the difference between a 5w40, does this matter in any scenario? (e.g. an oil shears out of grade and becomes closer to a 30 at operating temp, offering less protection)
2. If my manual calls for 10w30, would it ever/always/never make sense to choose a lower Winter grade like 0w30 or 5w30?

OK - your “beliefs”

1. True. Better/easier starting in cold. But you’re not in cold in FL. Ever.

2. No. This is just not true. There is no “protection” difference. The oil flows. Or it doesn’t.

3. Absolutely, no. The fuel efficiency impact depends solely on the operating temperature viscosity. Not the winter rating - Unless all you drive is one mile trips and the oil never warms up.

For your questions

1. Depends on the quality of the VII. In general, no, the “greater spread” does not mean “greater shear”. So much depends on base stocks and quality of VII that you can’t make that assumption.

2. In Florida- no. It makes no difference. Move to Northern Vermont, and yeah, you’ll want a lower winter rating and I would go 0W30. In fact, for the cars that are operated in extreme cold, I have done just that.

 

[OVERKILL]

"All else being equal" a 0W-40 will have more VII than a 5W-40. But all else is rarely equal and a narrower spread may in fact have MORE VII than a 0W-40, by virtue of using less expensive base stocks. I've posted several examples from the Mobil blending guide in the past that illustrate this.

Euro approvals also have "Stay in grade" requirements that limit the amount of permitted viscosity loss due to shear.

0W-40 became a popular grade due to its ability to be recommended and remain appropriate basically anywhere on the planet, regardless of ambient conditions.

 

[svenson]

shear? protection? 0-40 and 0-30? 5-30 or 5-40?
if you read bitog and especially edyvw member all we hear is castrol 0-30,0-40 and mobil 0-40 or motul xmax 0-40 bcs. these oils have a better final product as these experts say.
so to your question in terms of grade , should be which 0x or which 5x ,not the grade in general..as i understand all this time i am here its not the brand or the grade but the final product that matters.there are excellent 0x or 5x and there are less good oils.in terms of specs and usage .
now there is also the opinion as long as it has your approval buy the cheapest one ,it doesnt matter if its 0x or 5x ,but splitting hairs here ,like you do, buy the one you read here that it is a good product, regardless of grade.

 

[edyvw]

Been researching oil for a few months now, starting to get the terminology etc.

I am trying to understand if there are any drawbacks to using a 0W oil if climate isn’t really a factor (I am in Florida where it’s almost always above 40°F).

My understanding is that 0W..

1. Better for cold starts (irrespective of ambient air temperature)
2. Better for cold climates (offers “better” protection for ambient temps -40°F to -13°F (-40°C to -25°C))
3. More fuel efficient (for both cold starts or cold climates, irrespective of operating temperature viscosity)

Can the claims above be applied across the board?

I haven’t read much of a downside to 0W, but am wondering..

1. In a multigrade oil, does the delta in grade for cold vs hot matter? For example, the difference in cold/hot between a 0w40 is greater than the difference between a 5w40, does this matter in any scenario? (e.g. an oil shears out of grade and becomes closer to a 30 at operating temp, offering less protection)
2. If my manual calls for 10w30, would it ever/always/never make sense to choose a lower Winter grade like 0w30 or 5w30?

It is final product. All things equal, 5W40 will be more shear stable than 0W40. But that is ALL things equal, same quality base stock polymers etc. But that is rarely the case. As @OVERKILL said, most 5W40 oils will use cheaper base stocks than 0W40. Castrol is prime example. Exception would be HPL, Motul 300V series etc.
I ran 0W40 on track, and 5W40 in mountains starting at -42f.
So, my choice in FL would strictly depend on quality of that specific oil not grade.

 

[johnmyster]

My dad's generation was skeptical of wide viscosity spreads, probably based on some consumer reports or popular mechanics 101 level article on sharing down.

Is that still really a concern? Do we really see it in UOAs? For BITOGER quality level of products meeting modern specification and changed on reasonable OCIs, can't we put that fear to rest by now?

 

[edyvw]

My dad's generation was skeptical of wide viscosity spreads, probably based on some consumer reports or popular mechanics 101 level article on sharing down.

Is that still really a concern? Do we really see it in UOAs? For BITOGER quality level of products meeting modern specification and changed on reasonable OCIs, can't we put that fear to rest by now?

I thought people put that fear a long time ago.

 

[BMWTurboDzl]

My dad's generation was skeptical of wide viscosity spreads, probably based on some consumer reports or popular mechanics 101 level article on sharing down.

Is that still really a concern? Do we really see it in UOAs? For BITOGER quality level of products meeting modern specification and changed on reasonable OCIs, can't we put that fear to rest by now?

Ya. M1 0w40 will initially drop to a high 30 early in the interval..Some people fret about this stuff.

 

[kschachn]

Ya. M1 0w40 will initially drop to a high 30 early in the interval..Some people fret about this stuff.

But this again is an assumption that isn’t a universal truth. How many of those viscosity deviations are due to fuel dilution? Is this the current formulation? Which engines? What operating conditions? How many are unreliable Blackstone analysis?

 

[kschachn]

Not cold starts? And by cold I mean cold like -40 cold? Not ambient 70 degree Fl winter.

Sure in FL, it does not matter, but 0w30 really made a big difference in startup in -40 temps. Is that not due to the "0" as opposed to "10"

Like you note he’s in Florida.

 

[BMWTurboDzl]

But this again is an assumption that isn’t a universal truth. How many of those viscosity deviations are due to fuel dilution? Is this the current formulation? Which engines? What operating conditions? How many are unreliable Blackstone analysis?

It's not an assumption. The UOAs show it shears early on. This is pretty much universal with all 0w40's.. 5w50 and 10w60 also tend to drop a grade early on. Now I've seen UOAs which show it'll thicken into a 40 grade once the miles pile up (7.5k or greater) but most people around hear lose their minds if they go longer than 5k miles.

 

[edyvw]

It's not an assumption. The UOAs show it shears early on. This is pretty much universal with all 0w40's.. 5w50 and 10w60 also tend to drop a grade early on. Now I've seen UOAs which show it'll thicken into a 40 grade once the miles pile up (7.5k or greater) but most people around hear lose their minds if they go longer than 5k miles.

In my VW CC Mobil1 0W40 API SM, which people claimed drops immediately to high 30 grade, dropped from 13.5cst to 13.3cst after 5k in the DI engine. Let's say there is MOE, so it is 13. Still, in grade.
I would say it depends on numerous different factors, exploitation primarily. City driving and short trips will definitely do that.

Here is my Castrol UOA in BMW. Right column is 0W30, left is 0W40. VOA of 0W30 is 11.6cst, but let;s assume it is 12.1cst.
0W40 starts around 13.1, and that oil batch has a lot of track miles, including sessions 1 1/2 hours long at 101f at 5,100ft altitude.
For such exploitation time, drop in grade is absolutely insignificant. 0W30 spent time in winter in a really, really cold environment.

 

[OVERKILL]

It's not an assumption. The UOAs show it shears early on. This is pretty much universal with all 0w40's.. 5w50 and 10w60 also tend to drop a grade early on. Now I've seen UOAs which show it'll thicken into a 40 grade once the miles pile up (7.5k or greater) but most people around hear lose their minds if they go longer than 5k miles.

@High Performance Lubricants 0W-40 with 0.9% fuel went from 13.8cSt to 13.2cSt in my SRT in 6,000 miles, definitely a long ways from dropping a grade. Now, the Ravenol SSL 0W-40 that I ran before that was 12.0cSt with 0.8% fuel, which I think illustrates your point, with some viscosity loss due to shear. This was the same viscosity M1 0W-40 ended up at in my M5, but that was with 5% fuel in the oil, so the M1 was considerably diluted.

 

[carviewsonic]

I use 0W30 in the winter for the -30's we see here in Alberta. It does make a difference starting at those bitter temps.
In the summer I use either 0W30 or 5W30, which-ever I have on hand.

 

[wpod]

Doesn’t 80% of engine wear happen during cold start? For example, starting the car in the morning with an ambient air temp of 60F

Some what. When the engine is cold the pistons aren't round, the heat activated additives in the oil isn't hot the engine is running richer so there is a bit more fuel to wash the cylinders of oil etc. Who has worn our a properly maintained engine is the question we need to be asking before chasing theory or products that have inconsequential returns. I learned that chasing inconsequential returns is not going to be a benefit in the 1980s. Just use a quality oil and change is sooner than later and make sure the air filter and intake is sealed and the water pump, coolant and hoses are good . and the engine will last until mechanical from poor quality happens and oil will not help that. I have used M1 0W-40 since it came on the market just because it will cover any use or abuse I put on my engines hot or cold.

 

[GSCJR]

Hyundai which has always recommended 5w-xx for as long as I can remember, is now recommending 0w-30 on select new engines; just my 2c on the use of 0w-xx.

They skipped the 0w-20 altogether.

 

[Astro14]

Hyundai which has always recommended 5w-xx for as long as I can remember, is now recommending 0w-30 on select new engines; just my 2c on the use of 0w-xx.

They skipped the 0w-20 altogether.

Hyundai is an interesting data point - they aren’t exactly known for engine durability.

When manufacturers like Porsche, BMW, Mercedes, and other high performance marques, recommend 0WXX, and have developed their own certifications and approvals, it’s quite clear that a 0WXX can meet a very high standard for both performance and durability.

 

[wpod]

Hyundai is an interesting data point - they aren’t exactly known for engine durability.

When manufacturers like Porsche, BMW, Mercedes, and other high performance marques, recommend 0WXX, and have developed their own certifications and approvals, it’s quite clear that a 0WXX can meet a very high standard for both performance and durability.

This post nailed it . Precise concise and exact.

 

[edyvw]

Hyundai is an interesting data point - they aren’t exactly known for engine durability.

When manufacturers like Porsche, BMW, Mercedes, and other high performance marques, recommend 0WXX, and have developed their own certifications and approvals, it’s quite clear that a 0WXX can meet a very high standard for both performance and durability.

They also recommended ACEA A5 OR ABOVE before "above" existed.

 

[BMWTurboDzl]

In my VW CC Mobil1 0W40 API SM, which people claimed drops immediately to high 30 grade, dropped from 13.5cst to 13.3cst after 5k in the DI engine. Let's say there is MOE, so it is 13. Still, in grade.
I would say it depends on numerous different factors, exploitation primarily. City driving and short trips will definitely do that.

Here is my Castrol UOA in BMW. Right column is 0W30, left is 0W40. VOA of 0W30 is 11.6cst, but let;s assume it is 12.1cst.
0W40 starts around 13.1, and that oil batch has a lot of track miles, including sessions 1 1/2 hours long at 101f at 5,100ft altitude.
For such exploitation time, drop in grade is absolutely insignificant. 0W30 spent time in winter in a really, really cold environment.

View attachment 244006

Sure but pull up any UOA on M1 0w40 and you'll more likely than not see shear. IIRC Redline 0w40 does the same.

 

[BMWTurboDzl]

@High Performance Lubricants 0W-40 with 0.9% fuel went from 13.8cSt to 13.2cSt in my SRT in 6,000 miles, definitely a long ways from dropping a grade. Now, the Ravenol SSL 0W-40 that I ran before that was 12.0cSt with 0.8% fuel, which I think illustrates your point, with some viscosity loss due to shear. This was the same viscosity M1 0W-40 ended up at in my M5, but that was with 5% fuel in the oil, so the M1 was considerably diluted.

Ya I was going to mention your fill with Ravenol. I really don't see why this is such an issue. Most 0w40 are susceptible to falling out of grade simply because they lack the headroom. It's not a big deal anyways. I mean who gives a rats behind if an 0w40 temporarily shears into a heavy 30 grade. Big freaking deal.