What's the advantage of 5W & 10W over 0W?

Messages
9
Location
West Michigan USA
It's been quite awhile since I've been on this site and even longer since I posted. I got the "oil bug" tonight and I'm trying to learn. I've done a search on this site for the answer to my question and I'm frankly shocked that I didn't find a thread covering it. Maybe I didn't do the proper search procedure? Anyhow, my simple question is this: what is the advantage of using an oil weight beginning with 5W, 10W, or 15W, over a weight oil beginning with 0W? I do understand that, for example, there are more additives needed to make a 0W30 oil than a 5W30 oil, and those oils with a "bigger spread" will break down or shear sooner than oils having a "smaller spread". That being said, it would stand to reason that, in the identical application and environment, a vehicle using 0W30 oil should have it's oil changed sooner than the vehicle using 5W30, all things being equal. But the advantage of the 0W30 oil is that its viscosity at cold temperatures is less, allowing it to be pumped faster to moving engine components, presumably reducing metal-to-metal wear over time. I'm no expert here, this is just what I've gathered reading lots of posts and articles and based on some semblance of logic. If what I've said so far is true, then it would seem that the owner of a vehicle that recommends 5W30 should instead use 0W30 to prevent cold start wear and change his oil "somewhat before" the recommended mileage based on the oil having slightly less protection against shear and thermal breakdown, just to be on the safe side. My '83 Suzuki 650 air-cooled twin bike takes 10W40, so why not use 0W40 and change it out at 2000 miles instead of 3000 miles and gain the cold start advantages? My new Can Am Maverick Trail 1000 water-cooled twin side by side takes 5W40, so why not use 0W40 and change the oil every 40 hours instead of 50 hours? Now maybe there is no reason to change out a 0W sooner than a 5W or 10W oil -- that answer is for someone with far more engineering and chemical knowledge than me. From my own experience, I think much of when the oil is changed depends on the engine and how much "junk" it's putting into the oil, like acids and other contaminants. In power sports applications, especially air-cooled motorcycles that share the engine oil with the transmission (like my Suzuki), I think that oil will break much faster than oil in vehicles that are water cooled and don't have shared transmissions. With today's oil technology, oil changes in most vehicles are going way out there, sometimes over 10,000 miles. I'll tell you that with my '02 Bonneville (3.8L V6), that oil gets very dark brown in a couple thousand miles, and I use basic 5W30 in winter and 10W30 in summer and change it out well before 3000 miles. In my '07 Express van (5.3L V8) I can drive 5000 miles and the oil is a light brown. My point is, when an oil needs to be changed depends largely on the vehicle and the application. I'd like to know, why wouldn't almost every "enthusiast" go to a 0W weight oil, in every "non racing" application, unless they want to maximize the amount of miles between oil changes? I realize there are lots of people who want to buy the cheapest oil available, which will be 5W or 10W petroleum oils. I assume that most of the people on this site don't fall into that group. Thanks!!
 
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6,321
Location
San Francisco Bay Area
All things aren't equal though. I use Mobil 1 0W-40. I know that 5W-30 is the "preferred" weight for my 2004 WRX, but I'm getting kind of lazy with my oil changes (going to full "normal" OCI and maybe beyond) and I understand that the 0W-40 is essentially an extended life oil with a higher ZDDP level (not allowed in ISLAC oils) and a higher TBN. Oil is kind of tricky. I've been a user of Mobil 1 back in the day when they were well known as a PAO/ester blend and before they switched to mostly a Group III base oil. But these days who knows. I wouldn't necessarily say that a 0W oil is going to be less robust than something of heavier weight. Sometimes there are various things that happen intentionally. Mobil 1 0W-40 is apparently meant to shear down a little bit into the 30 wt range and then thicken up via oxidation so that in the sequence tests it maintains viscosity. And the oil that I use is specifically meant to be used in an extended OCI application for Mercedes-Benz, although the current version seems to have lost the BMW LL-01 approval.
 
Messages
11,844
Location
PA
I don't think a higher W rating offers any advantages per se. I think it's more the case that certain goals (e.g. high shear stability, low volatility) are easier to achieve if you're willing to accept a higher W number.
 
Messages
692
Location
Alberta
I'm going to switch from the recommended 5w20 to 0w30 year round in our Honda Accord. Our climate here ranges from -35C to +35c each year, and the driving ranges from tons of short tripping to extended highway trips. So I figure that 0W30 will provide a bit more protection at each end. From what I understand, 0W oils have more group IV in their base to get the 0W performance. For your bike and side by side which would never be used in -35C weather, the 0W would not really offer any advantage over a 5W or 10W. Both would reach engine components at the same time in 'normal' ambient temps. Disadvantage of 0W oils is that they tend to have slightly lower HTHS values compared to 5W or 10W, and may shear out of grade sooner. They also seem to be a bit pricier.
 
Messages
218
Location
Knoxville, Tennessee
There are a couple of factors to consider with your post. Motorcycles with wet clutches (clutches that share oil with the engine) don't do well with oils that have friction modifiers typically found in 0W & 5W oils. They can cause the clutch to slip prematurely. That is why motorcycle-rated oils are recommended. Usually it is a JASO MA rating. Interestingly, diesel oils sometimes have that rating. For cars, modern cars are designed with tighter clearances that work well with thinner oils. My old Jeep 4.0 is not modern. I prefer 10W oils especially in the summer because they tend not to leak as much and theoretically don't shear as quickly as an oil with a wider spread between the cold and hot numbers. I don't get as concerned with the startup friction due to cold oil flow because tight tolerances and Jeeps really don't go together. I do use exclusively synthetic and don't stretch my OCI, so it is not a question of longevity and the .25mpg difference is irrelevant to my life. Just use a cheap/readily-available synthetic in the ballpark of the recommended grade with a reasonable OCI and the car will wear out before the engine.
 
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3,854
Location
Slovenia EU
I would speak for 5w&10W......since 0W is pointless for EU ( we dont use these oils here) smile 10W......in 98% it is semisyn (unless in Rimula case and usually in MC oils)....decent all around oil.....less spread means less shear (oil consumption)... But since nowadays cars all have turbos.......I am more fan of 5W oils....that way you get at least gr. III synthetic... Would like to have your Rotella T6 15w40 here smile
 
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4,291
Location
Central Wisconsin
5W and 10W does give you a slightly better wear protection IMHO. It is also a buffer in case of fuel dilution which seems common with GDI fuel systems. There are far more choices of oils with the 5W/10W oils as well, though more 0W oils are appearing. Canada and Alaska may benefit from 0W oils in the dead of winter, but not NEEDED in most of the US. My 2¢
 
Messages
41
Location
Michigan
In the wintertime it takes up to 30 minutes for oil to reach normal operating temperature, even if the coolant reaches normal temp long before. As the oil is warming up the 0W-XX grades provide a substantial reduction in viscosity over the 10W-XX grades. Thus the viscosity reducing benefits of 0W-XX extend well beyond initial startup. Why would you want your engine plowing through overly thick oil during this period? It wastes gas and makes the engine feel sluggish. The only compelling argument for using 10W-XX oil is if there is a consumption problem with thinner oil or if the climate is moderate AND the engine operates often at high loads and RPMs. Even that concern is questionable because the 0W-XX oils are invariably made from synthetic base stocks and meet demanding performance requirements from Porsche, MB, Audi, etc.
 
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11,844
Location
PA
Originally Posted by dwendt44
5W and 10W does give you a slightly better wear protection IMHO. It is also a buffer in case of fuel dilution which seems common with GDI fuel systems.
Wow. These claims are completely new to me. Got a source?
 
Messages
2,046
Location
Oregon
Generally speaking, with a 10W you can get an oil with a lower volatility (thicker blend of base stocks). You just have to live in the right climate. Keep in mind I said generally speaking. Of course there's low volatility 0W and 5W oils.
 
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3,275
Location
On another site
Originally Posted by d00df00d
Originally Posted by dwendt44
5W and 10W does give you a slightly better wear protection IMHO. It is also a buffer in case of fuel dilution which seems common with GDI fuel systems.
Wow. These claims are completely new to me. Got a source?
I'd like to see that also. However, (I could not find the thread) but it was posted here somewhere that a 15W or 10W resulted in less timing chain wear in the same engine.
 
Messages
3,854
Location
Slovenia EU
Originally Posted by SandCastle
The only compelling argument for using 10W-XX oil is if there is a consumption problem with thinner oil or if the climate is moderate AND the engine operates often at high loads and RPMs. Even that concern is questionable because the 0W-XX oils are invariably made from synthetic base stocks and meet demanding performance requirements from Porsche, MB, Audi, etc.
LoL... Nowadays HC syntese (XHVI) 10w40 oils like shel XH7 are in pair with gr. III 5W synthetic....except for pour point...everything else is the same... Both 10w & 5w here meets the "holy trinity" requirements (mb&vw&bmw)... Maybe 10w not the stringest ones as 5w....but still way beyond of needs of any USA N/A nowadays engine... No API / ILSAC water over here....
 
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Messages
3,561
Location
Central Iowa
Originally Posted by 1JZ_E46
Generally speaking, with a 10W you can get an oil with a lower volatility (thicker blend of base stocks). You just have to live in the right climate. Keep in mind I said generally speaking. Of course there's low volatility 0W and 5W oils.
i have grown fond of using 10w30 in virtually all my applications. My wife's Cadillac CTS, my 2015 Silverado 3/4 ton, my OPE, and my commercial trucks (HDEO in them). The only thing I have that doesn't get a 10w30 is my Triumph Bonneville that gets a 10w40. Central Iowa winters and summers. We hit some -25F actual temps this winter. It is not uncommon for 100F+ in the summer. 10w30 across the board. Not advocating anyone else follow the pattern, but it works for me. My wife's Cadillac CTS is a 2006 and we are not getting rid of it anytime soon. My commercial truck just turned 952,000 miles and still only uses a quart of oil every 11,000 miles. My JD zero turn mower also runs on 10w30 as does my Yamaha generator. I am not convinced that I need a 0w30 or 5w30 for anything. If I were to every move back to the interior of Alaska, then I will take a second look at those.
 
Messages
7,011
Location
Wet side WA
It gives you extra choices that may be on sale cheaper. Example in case 0w-20 on sale at Walmart for $14 and then you get a $10 rebate on each Jug. $4 a Jug is a price you can live with.
 
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Messages
1,784
Location
South Carolina
The biggest difference is viscosity index improver. It's required in conventional and most synthetic oils to achieve these wide spread mutli-grades. However, VIIs are volatile and shear easily. Combined with the higher use of low viscosity base oils, this is why you'll notice 0w-xx oils will tend to have a lower HTHS and higher NOACK compared to 5w-xx and 10w-xx oils. It's why 0w-40, 5w-40, and 10w-40 oils can get API approved with an HTHS150 of just 3.5 cP, but 15w-40 and higher requires 3.7 cP. Depending on many factors like your budget, engine, use, climate, etc... this may be meaningless to you. If you find an oil you like, that doesn't consume a lot, the engine runs quiet, and other positives, then go with it.
 
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Messages
17,100
Location
Upper Midwest
Originally Posted by RDY4WAR
The biggest difference is viscosity index improver. It's required in conventional and most synthetic oils to achieve these wide spread mutli-grades. However, VIIs are volatile and shear easily. Combined with the higher use of low viscosity base oils, this is why you'll notice 0w-xx oils will tend to have a lower HTHS and higher NOACK compared to 5w-xx and 10w-xx oils. It's why 0w-40, 5w-40, and 10w-40 oils can get API approved with an HTHS150 of just 3.5 cP, but 15w-40 and higher requires 3.7 cP.
This is the second time in a few days where I've seen someone say VII are volatile. Where have you seen this? Viscosity index improvers are high molecular weight polymers, how on earth are they volatile? Million molecular weight molecules don't just run off into the atmosphere. And the second thing about them shearing "easily" has never been shown. In fact, most motor oil here regardless of grade shows good viscosity stability. In a motorcycle with a shared sump is one thing, but SonofJoe has stated that modern VII are quite stable and as far as I know we see very little verifiable viscosity degradation here due to shearing. Viscosity deviation in UOA on Bitog is typically due to fuel dilution.
 

4WD

Messages
16,709
Location
Texas
Well said … we are seeing dilution attack base fluids … or minor temporary reduction … if there was a permanent burst problem the 0w40's would not get Porche or other serious specs …
 
Messages
223
Location
Iowa City
Originally Posted by kschachn
Originally Posted by RDY4WAR
The biggest difference is viscosity index improver. It's required in conventional and most synthetic oils to achieve these wide spread mutli-grades. However, VIIs are volatile and shear easily. Combined with the higher use of low viscosity base oils, this is why you'll notice 0w-xx oils will tend to have a lower HTHS and higher NOACK compared to 5w-xx and 10w-xx oils. It's why 0w-40, 5w-40, and 10w-40 oils can get API approved with an HTHS150 of just 3.5 cP, but 15w-40 and higher requires 3.7 cP.
This is the second time in a few days where I've seen someone say VII are volatile. Where have you seen this? Viscosity index improvers are high molecular weight polymers, how on earth are they volatile? Million molecular weight molecules don't just run off into the atmosphere. And the second thing about them shearing "easily" has never been shown. In fact, most motor oil here regardless of grade shows good viscosity stability. In a motorcycle with a shared sump is one thing, but SonofJoe has stated that modern VII are quite stable and as far as I know we see very little verifiable viscosity degradation here due to shearing. Viscosity deviation in UOA on Bitog is typically due to fuel dilution.
Mechanical shearing will break VI polymers, as well as high heat and pressure can cause molecule cracking according to Machine Lubrication articles. Oil Blenders can use both high or low molecular weight polymers to achieve their performance goals
 
Messages
17,100
Location
Upper Midwest
Originally Posted by Talent_Keyhole
Mechanical shearing will break VI polymers, as well as high heat and pressure can cause molecule cracking according to Machine Lubrication articles.
Yes it can.
 
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