It'd be fine.
Valvoline Max Life (synthetic) 10w-30 = 6.3% Noack
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Even at 40C
Originally Posted By: Hermann
Originally Posted By: 901Memphis
Plenty of 10w30 synthetics hit 6-7% NOACK. It's easier to hit lower NOACK compared to a 5w30, but a 5w30 is almost always superior imho.
How?
Even at 40C (104F) a 5w30 synthetic has a viscosity of 55.8 - 65.2 cSt which is thicker than even an SAE 60 motor oil at 100C, far too thick to provide adequate protection to the entire engine under demanding load. An SAE 60 will be between 21.9 and 26.1 cSt at 100C and thats far better flowing than even a 5w30 synthetic in the summer Florida heat when you first turn the key.
If your engine sees cold starts, then the 5w30 synthetic is Superior to 10w30 if the engine specs either. A cold start is a cold start whether its winter in Wyoming or Summer in Arizona.
If you only warm up your engine 1 time per OCI and drive the car forever at 100C across the country then a 10w30 is superior since you won't see as much cold star wear.
Whether or not the amount of wear is measurable is another question, but better flow is better flow and i will not pay the same amount for a 10w30 synthetic when the 5w30 is right there on the shelf unless its going in a lawnmower.
Now if i find some 10w30 PU on clearance at a ridiculous price you better believe i would use it in the summer in a 5w30 application, but i won't go out of my way to buy it.
Originally Posted By: Hermann
Originally Posted By: 901Memphis
Plenty of 10w30 synthetics hit 6-7% NOACK. It's easier to hit lower NOACK compared to a 5w30, but a 5w30 is almost always superior imho.
How?
Even at 40C (104F) a 5w30 synthetic has a viscosity of 55.8 - 65.2 cSt which is thicker than even an SAE 60 motor oil at 100C, far too thick to provide adequate protection to the entire engine under demanding load. An SAE 60 will be between 21.9 and 26.1 cSt at 100C and thats far better flowing than even a 5w30 synthetic in the summer Florida heat when you first turn the key.
If your engine sees cold starts, then the 5w30 synthetic is Superior to 10w30 if the engine specs either. A cold start is a cold start whether its winter in Wyoming or Summer in Arizona.
If you only warm up your engine 1 time per OCI and drive the car forever at 100C across the country then a 10w30 is superior since you won't see as much cold star wear.
Whether or not the amount of wear is measurable is another question, but better flow is better flow and i will not pay the same amount for a 10w30 synthetic when the 5w30 is right there on the shelf unless its going in a lawnmower.
Now if i find some 10w30 PU on clearance at a ridiculous price you better believe i would use it in the summer in a 5w30 application, but i won't go out of my way to buy it.
wemay
Site Donor 2023
At operating temps, the 10w flows better than the 5w because it is lighter as well. This fact lends credence to your argument but not at startup, instead applying to the rest of the drive. No?
As you said though, differences in wear may very well be indistinguishable.
As you said though, differences in wear may very well be indistinguishable.
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30 weight spec is 9.3 - <12.5 cSt whether its 5w30 or 10w30, so the lighter one at operating temp will vary depending on the batch. All things being equal a 5w30 and 10w30 should be the same viscosity at 100C.
wemay
Site Donor 2023
Originally Posted By: 901Memphis
Even at 40C (104F) a 5w30 synthetic has a viscosity of 55.8 - 65.2 cSt which is thicker than even an SAE 60 motor oil at 100C, far too thick to provide adequate protection to the entire engine under demanding load.
How do you reason this ?
The thicker viscosity increases the separation distances of parts, and pushes the whole show across to the right on the Striebeck curve, away from boundary lubrication.
How then is it too thick to provide protection ?
Given that we are talking about a starting heat that most of us would be baking in, not the oft quoted straight weight at -35 cold start.
Even at 40C (104F) a 5w30 synthetic has a viscosity of 55.8 - 65.2 cSt which is thicker than even an SAE 60 motor oil at 100C, far too thick to provide adequate protection to the entire engine under demanding load.
How do you reason this ?
The thicker viscosity increases the separation distances of parts, and pushes the whole show across to the right on the Striebeck curve, away from boundary lubrication.
How then is it too thick to provide protection ?
Given that we are talking about a starting heat that most of us would be baking in, not the oft quoted straight weight at -35 cold start.
...which all my vehicles have experienced (and colder yet) with 5w-XX oils.
If the 10w30 went on clearance where I live, I would buy it all up and use it all my vehicles including my parents vehicles. 10w30 is good to go. If the weather is greater than zero degrees, it flows the same as 5w30.
Near freezing in FL? I went to Texas two months ago and people still had long sleeve shirts on. Guess living in Wyoming made me more tolerant to the cold. Now in KS you can have 30 days of 100+ and a humidity of a rain forest followed by 40 degree drops in two hours. Think one time we had a ice storm and tornado at the same time lol. Noack of 9 or less is just awesome! 6.3 is getting into PU/Redline 5w30 territory there. Would be a good oil for a older truck on hot summer day. Could use a qt in conjunction with 5w30 VM to get a lower noack if the 5 is a bit too high for your liking.
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