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

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223
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Iowa City
Originally Posted by TiredTrucker
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.
For those who do not garage their vehicles during those -10 to -25 degree periods, going with 5w or 0w is advisable, especially with newer engines with VVT.
 
Last edited:
Originally Posted by Talent_Keyhole
For those who do not garage their vehicles during those -10 to -25 degree periods, going with 5w or 0w is advisable, especially with newer engines with VVT.
Agreed. The 1.4l Multiair engine in my 500 Abarth says it's programmed not to start below -30C if the block heater isn't plugged in. It specs 5w40 (nothing else). I have a feeling that is due to a need to have a thin enough oil to allow the Multiair system to function properly (no throttle valve, the system uses variable intake valve opening to throttle the engine). I don't know why they don't spec a 0w40 for cold climates like Northern Alberta since some people report having no issues using it.
 
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1,784
Location
South Carolina
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.
I would like to apologize for the misinformation. I did some searching and found a white paper that stated VIIs have low volatility. I drew my conclusion from looking at HTHS and volatility between the grades. Take Amsoil OE line for example. The further the spread, one would assume the more VII. Volatility also increases with a wider spread and HTHS goes down. That's how I drew that conclusion. If VII isn't the culprit, what causes the 0w-20 to have a lower HTHS and higher volatility than 5w-20? [Linked Image]
 

JAG

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5,320
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Fredericksburg, VA
VIIs are very viscous, so when a larger dose of them is used and the [email protected] is kept roughly constant, the base oil mix needs to be made less viscous. Oils with VIIs undergo temporary viscosity loss at high shear rates, which the HTHS has, so for equal [email protected], the oil with more VIIs will have a lower HTHS than an oil that's the same other than the base oil mix's viscosity. It's called temporary viscosity loss when the viscosity in whatever test is the same before and after the high shear rate event. It's caused by the large, flexible VII molecules aligning along the direction of shearing. It's permanent viscosity loss when some of the VIIs have been broken apart, reducing the viscosity at any temperature and shear rate.
 
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On another site
Originally Posted by TiredTrucker
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.
Is that the Schaeffer 7000 for gas engines or one of the diesel oils?
 

OVERKILL

$100 Site Donor 2021
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45,911
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Ontario, Canada
Originally Posted by RDY4WAR
If VII isn't the culprit, what causes the 0w-20 to have a lower HTHS and higher volatility than 5w-20?
They use a lighter base oil, because OE and XL aren't PAO, so that 0w-20 is probably at least mostly, based with 4cSt Yubase or similar.
 
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1,784
Location
South Carolina
Originally Posted by OVERKILL
Originally Posted by RDY4WAR
If VII isn't the culprit, what causes the 0w-20 to have a lower HTHS and higher volatility than 5w-20?
They use a lighter base oil, because OE and XL aren't PAO, so that 0w-20 is probably at least mostly, based with 4cSt Yubase or similar.
Bleh... I think I'd rather use high viscosity PAO and blend in low viscosity POE (PE32) to get the desired KV100. smile
 
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