What's the lowest ambient air temp you'd feel safe using SAE 30 in a modern car?
SAE 30
- Thread starter Ryan_in_MN
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+40 degrees Fahrenheit.
Freezing Point 0C / 32F
Throwing a bit of data at it...the following was proposed by Selby when he was researching the failures that occurred in oil gelling in cold temperatures...and enine failures arising.
"StartabilityI is a CCS type measure, and "Flow to the pump" was MRV basically.
"Flow to Engine"...there was no viscometer that represented that factor.
"Gelation Index" was a cooling process designed to produce gelling at the temperature.
0C looks like a good point to stop playing.
Now look at the modern J300...
Note that the temperatures are different, and the viscosities are different...the allowable MRV viscosity, which is the ability to "fall" into the oil pump suction has doubled...at very low temperatures, viscosities doble every 5 degrees that you drop...so 30,000Cp at -35 is ostensibly the same as 60,000Cp at -40C, except that by making it -40, they are ensuring in the J300 example that the oil isn't "gelling", or becoming semi solid.
The CCS has halved...give or take.
So using these as a guideline, and density of 1 as a first approximation (it's about 15% out - High)...
Pennzoil SAE30
0C - 1,600Cp
-5C - 2,650Cp
-10C - 4,500Cp
-15C - 8,100Cp
-20C - 15,300Cp
-25C - 30,600Cp
Assuming that there's no gelation issues on a modern largely GrII oil (105 VI for this oil), it's probably close to a 20W, or 25W in cold temperature performance, so should be good to -10C...I've run PYB SAE30 at -7C no issues, (and a 25W70)
Freezing is perfectly safe.
-5, and I wouldn't break a sweat, -10 is starting to stretch the friendship.
If it's black and gold no name, don't go below freezing (don't buy it preferably).
If it's Amsoil ACD, then it's also a 10W, take it to -25C.
Apologies for the long winded reply, just was an interesting question.
"StartabilityI is a CCS type measure, and "Flow to the pump" was MRV basically.
"Flow to Engine"...there was no viscometer that represented that factor.
"Gelation Index" was a cooling process designed to produce gelling at the temperature.
0C looks like a good point to stop playing.
Now look at the modern J300...
Note that the temperatures are different, and the viscosities are different...the allowable MRV viscosity, which is the ability to "fall" into the oil pump suction has doubled...at very low temperatures, viscosities doble every 5 degrees that you drop...so 30,000Cp at -35 is ostensibly the same as 60,000Cp at -40C, except that by making it -40, they are ensuring in the J300 example that the oil isn't "gelling", or becoming semi solid.
The CCS has halved...give or take.
So using these as a guideline, and density of 1 as a first approximation (it's about 15% out - High)...
Pennzoil SAE30
0C - 1,600Cp
-5C - 2,650Cp
-10C - 4,500Cp
-15C - 8,100Cp
-20C - 15,300Cp
-25C - 30,600Cp
Assuming that there's no gelation issues on a modern largely GrII oil (105 VI for this oil), it's probably close to a 20W, or 25W in cold temperature performance, so should be good to -10C...I've run PYB SAE30 at -7C no issues, (and a 25W70)
Freezing is perfectly safe.
-5, and I wouldn't break a sweat, -10 is starting to stretch the friendship.
If it's black and gold no name, don't go below freezing (don't buy it preferably).
If it's Amsoil ACD, then it's also a 10W, take it to -25C.
Apologies for the long winded reply, just was an interesting question.
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My experience with 30wt was freezing was where the oil started to get taxed. To be fair however, the oil I was using was speculated to be a basic group I or II base. A modern PCMO 30 may do a little better.
I ran two intervals of SAE 30, one interval with Delo 400 SAE 30, and the other with SJ Kendall GT-1 SAE 30. The latter was speculated to be group I/II, while Delo seems to be II+. Both oils did fine down to freezing and below, at which I had short lived start up lifter clatter.
So, long answer shortened, my opinion is it's good down to freezing.
I ran two intervals of SAE 30, one interval with Delo 400 SAE 30, and the other with SJ Kendall GT-1 SAE 30. The latter was speculated to be group I/II, while Delo seems to be II+. Both oils did fine down to freezing and below, at which I had short lived start up lifter clatter.
So, long answer shortened, my opinion is it's good down to freezing.
With Shannow's papers and Red91's experience with multiple runs on SAE 30 the OP has a good answer.
Good to hear from you again Red91
Good to hear from you again Red91
Occasionally, there are full synthetic oils rated as straight 30. I would expect better flow at low temperatures with such a choice, vs a conventional straight 30.
Originally Posted By: Cujet
Occasionally, there are full synthetic oils rated as straight 30. I would expect better flow at low temperatures with such a choice, vs a conventional straight 30.
I've heard of a synthetic SAE 30 which also passes as a 10W30.
Edit: This is it, Amsoil SAE30 / 10W30 Heavy Duty
https://www.amsoil.com/shop/by-product/m...duty-motor-oil/
Occasionally, there are full synthetic oils rated as straight 30. I would expect better flow at low temperatures with such a choice, vs a conventional straight 30.
I've heard of a synthetic SAE 30 which also passes as a 10W30.
Edit: This is it, Amsoil SAE30 / 10W30 Heavy Duty
https://www.amsoil.com/shop/by-product/m...duty-motor-oil/
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Above freezing point
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Originally Posted By: SR5
Originally Posted By: Cujet
Occasionally, there are full synthetic oils rated as straight 30. I would expect better flow at low temperatures with such a choice, vs a conventional straight 30.
I've heard of a synthetic SAE 30 which also passes as a 10W30.
Edit: This is it, Amsoil SAE30 / 10W30 Heavy Duty
https://www.amsoil.com/shop/by-product/m...duty-motor-oil/
Yes, that's the one Shannow mentioned.
Originally Posted By: Cujet
Occasionally, there are full synthetic oils rated as straight 30. I would expect better flow at low temperatures with such a choice, vs a conventional straight 30.
I've heard of a synthetic SAE 30 which also passes as a 10W30.
Edit: This is it, Amsoil SAE30 / 10W30 Heavy Duty
https://www.amsoil.com/shop/by-product/m...duty-motor-oil/
Yes, that's the one Shannow mentioned.
Originally Posted By: Ryan_in_MN
What's the lowest ambient air temp you'd feel safe using SAE 30 in a modern car?
Ask the people who live around you.
Back in the 60's and 70's,(well, even the 80's) in North Dakota, we ran straight 30 to to WELL below 0*F in all farm equipment and most vehicles.
I have personally hand-crank started a 1950 Farmall M filled with straight 30 when it was -42*F (-41*C) and it got oil pressure relatively quickly.... I was surprised.
What's the lowest ambient air temp you'd feel safe using SAE 30 in a modern car?
Ask the people who live around you.
Back in the 60's and 70's,(well, even the 80's) in North Dakota, we ran straight 30 to to WELL below 0*F in all farm equipment and most vehicles.
I have personally hand-crank started a 1950 Farmall M filled with straight 30 when it was -42*F (-41*C) and it got oil pressure relatively quickly.... I was surprised.
Delo 30 weight would be, (for lack of better terms) a 20w30.
Many straight 30's look like multis on paper.
I've done straight 30's to below freezing, but feel more comfortable with a "real" multigrade for repeated starts in cold weather.
Many straight 30's look like multis on paper.
I've done straight 30's to below freezing, but feel more comfortable with a "real" multigrade for repeated starts in cold weather.
My forty nine Chevy started at twenty below more than once. Lots of choke and I didn't rush her. She idled until the temp gauge started to rise. 30 weight Mobil.
So you guys with the he-man stories of starting at sub-zero temps using straight weight oils are saying that is a good thing to do somehow? Wouldn't it be far better to use a multi-vis in those situations, considering it isn't 1960 any more?
I don't think anyone is telling the OP to run it well below freezing; they are only using their experience as a point of reference. I can tell a difference starting the Roadmaster at 39 F with 10W-40 vs a straight 30. The 10W-40 allows a quicker turn over. I'll probably go back to 30 next summer.
Thanks for the feedback guys. I have 10 quarts of leftover delo SAE 30 that I scored for cheap and would use in lawn equipment. I have since moved from MN to Las Vegas. No more lawn. Thinking of putting in my 2011 chevy truck come summer time to use it up.
Originally Posted By: Ryan_in_MN
Thanks for the feedback guys. I have 10 quarts of leftover delo SAE 30 that I scored for cheap and would use in lawn equipment. I have since moved from MN to Las Vegas. No more lawn. Thinking of putting in my 2011 chevy truck come summer time to use it up.
Ah, your question makes more sense to me now!
I would think you'd be fine with SAE30 in winter where you live now, unless you're planning to go do some skiing this winter...how cold do you expect it to get in Jan/Feb in Vegas?
Thanks for the feedback guys. I have 10 quarts of leftover delo SAE 30 that I scored for cheap and would use in lawn equipment. I have since moved from MN to Las Vegas. No more lawn. Thinking of putting in my 2011 chevy truck come summer time to use it up.
Ah, your question makes more sense to me now!
I would think you'd be fine with SAE30 in winter where you live now, unless you're planning to go do some skiing this winter...how cold do you expect it to get in Jan/Feb in Vegas?
Winters here from the weather data I looked at get about 38 for an average low. So, I'm going to get some days below freezing. I probably will just wait until March or April to put it in, since I never know if I'll venture out of the LV valley. Don't plan on it, but rather be safe than sorry.
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