How Cold is TOO Cold for SN+/SP "Conventional"?

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1,918
Location
British Columbia, Canada
So at what temps does a 5w-30 conventional start becoming a problem? 20 degree's F? 10 degree's F? I know the CCS falls within range but that doesn't really tell us much in terms of flow rate at startup right?

I once started a '63 Cadillac that had 10W-30 in the crankcase when it was about -40. I had a Sadie Hawkins week date and the Cadillac was borrowed from my room-mate. (It was actually his parents car.) It was sitting in a snow bank and had been plugged in (block heater) for a couple of hours.

It started but thumped gently for several minutes while the oil pressure light glowed bright red. I wanted to turn it off but my room-mate insisted we let it run. The car was fine afterwards as far as we could tell.

In my opinion, that was too thick combined with too cold.

I started my Accord V6 once with 5W-30 conventional in the sump, below -30C, when the car had been sitting outside overnight and then plugged in (block heater) for a few hours. It started and ran fine. If I was doing cold starts like that regularly I'd have used a 0W- oil instead. In normal circumstances that car would have been in an unheated garage attached to the house where the inside temperature was not much below freezing.
 
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11,682
Location
Colorado Springs
I once started a '63 Cadillac that had 10W-30 in the crankcase when it was about -40. I had a Sadie Hawkins week date and the Cadillac was borrowed from my room-mate. (It was actually his parents car.) It was sitting in a snow bank and had been plugged in (block heater) for a couple of hours.

It started but thumped gently for several minutes while the oil pressure light glowed bright red. I wanted to turn it off but my room-mate insisted we let it run. The car was fine afterwards as far as we could tell.

In my opinion, that was too thick combined with too cold.

I started my Accord V6 once with 5W-30 conventional in the sump, below -30C, when the car had been sitting outside overnight and then plugged in (block heater) for a few hours. It started and ran fine. If I was doing cold starts like that regularly I'd have used a 0W- oil instead. In normal circumstances that car would have been in an unheated garage attached to the house where the inside temperature was not much below freezing.
10W40 at -42. Though semi-synthetic.
It rattled for 10 second, and then engine just sound normal. Old style board computer on other hand was pixelated for 2hrs.
 
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469
Location
T-County, Ohio
The manual for my 2017 Hyundai Elantra 2.0 shows to use 5w20/5w30 if temps can be below 0*. And 10w30 can be used if temps stay above 0*. My 2010 Chrysler Sebring states that only 5w20 should be used.

L8R,
Matt
 
Here are the SAE cold cranking similar test numbers in Celsius. 5w is good for -30 C (-22 F) . 10 w Is good for -25 C (-13 F) . These are very practical numbers for cold starts. Our lows are around -32 C for a couple of days per year. My vehicles start fine without the block heater with 5w30 but I usually plug in the block heater at -20 C which results in a nice smooth start. You can hear the difference.

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So ran a search and surprised I couldn't find this asked already from this perspective, but apologies if I just missed it.

Have some PYB 5w-30 Syn Blend SP and a couple of quart bottles of PYB SN+ I was recently given that I've been considering using for my next change around the corner but being mid Sept this fill would run me through about mid to late November here in Colorado with frequent trips into the colder higher altitudes.

Which got me to wondering, that while we all know the cold weather startup advantages of a full or 100% synthetic how cold exactly is TOO cold for a modern "conventional" oil before it starts to become a likely issue at startup? We've seen the cold pour "tests" on Youtube but 90% of us won't be running into -25F temps even at higher altitudes here in Colorado so I don't find those really relevant or helpful (or accurate since pumps don't just drip oil into the motor from a cup lol).

So at what temps does a 5w-30 conventional start becoming a problem? 20 degree's F? 10 degree's F? I know the CCS falls within range but that doesn't really tell us much in terms of flow rate at startup right?

Educate us BITOG! :)

Quick Edit: For my personal application it would be going into a Subaru 3.6 H6 and was originally designed for conventional oil anyway, so no issues as far as compatibility with the motor is concerned.

Those You Tube cold start videos that show the difference of conventional vs synthetic oils are typically done at -40. At temperatures down to -30 C (-22) There is no difference beteen a conventional and a synthetic 5w30 in cold starting ability.
 
Messages
2,399
Location
WY
I have started multiple vehicles @-35F and lower after cold soaking at my workplace parking lot for 12+ hours. They start poorly, idle poorly and run poorly until somewhat warmed up. Many automatic transmissions will not shift above 2nd gear until the transmission builds heat. Manual transmission vehicles take extra effort in gear selection as it feels like they are full of taffy. After my first winter here 15 years ago, I changed to 100% synthetic oils just for the cold flow/pumping characteristics. I have also installed engine heaters on my daily work drivers which are great if I manage to get a parking spot with a receptacle. It is interesting how cold air sinks. It can be -40F along the river in the parking lot and a balmy -20F 1/4 mile away at the entrance gate into the plant on the bluff maybe 100 feet higher in elevation. The coldest I have seen it was on Interstate 25 near Casper at the bottom of a draw where my car temperature readout was -58F and, like usual, a warm -35F at the top of the grade. I can tell you this. Wyoming is going to be in my rear view mirror when I retire.
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16,394
Location
...
My dad started up his TraveAll in -30F conditions in eastern Oregon running Havoline SAE 30. The engine in that cornbinder clicked and clacked for around 30 seconds before settling in. Then he took a stick he had cut to the right length and place it between the seat and the throttle and went back in for another cup of coffee.

He bought a pan heater to make it easier on the engine.
 

4WD

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15,773
Location
Texas
With more use of Grp2+ … some 15w40’s are closer to a 10w40 … but in the HDEO market the formulator has both a performance and customer target …
 

4WD

Messages
15,773
Location
Texas
My dad started up his TraveAll in -30F conditions in eastern Oregon running Havoline SAE 30. The engine in that cornbinder clicked and clacked for around 30 seconds before settling in. Then he took a stick he had cut to the right length and place it between the seat and the throttle and went back in for another cup of coffee.

He bought a pan heater to make it easier on the engine.
Not to worry … the camshaft was well “greased” 😳
 
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11,682
Location
Colorado Springs
If (it) dies, (it) dies. - Ivan Drago, Rocky 4.

You cannot survive Russian winter (accent.)
Lol, did not think of him.
Well, the vehicle in question was German, and Bosnia is far away from Russia :)
In 80's and 90's 15W40/10W40 was go to oil in Europe. And winters back then were much colder.
 
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16,530
Location
Upper Midwest
Here are the SAE cold cranking similar test numbers in Celsius. 5w is good for -30 C (-22 F) . 10 w Is good for -25 C (-13 F) . These are very practical numbers for cold starts. Our lows are around -32 C for a couple of days per year. My vehicles start fine without the block heater with 5w30 but I usually plug in the block heater at -20 C which results in a nice smooth start. You can hear the difference.
Cranking is one thing and can be somewhat mitigated by a good battery. Pumpability is another, if the oil gels in the vicinity of the pump pickup tube and cannot be pumped then it's game over.
 
Messages
1,438
Location
Indiana
Ran 20W50 Valvoline one winter in Flint Mich in 302 sb chevy, couple times needed a jump start to crank it, but it didn't blow up.

One of the things we learned at Allison is there's a big difference in priming between cooling down to -40 and running vs. cooling down to -40, sitting at -40 for 12 hours and then running.
 

Subie5w30

Thread starter
Messages
57
Location
Colorado
The last owners manuals I read where multiple grades were recommended/approved, for a late 3rd gen F-body, it said 10w30 is good for over 0F, and straight 30 is good for over 40F.

The Infiniti J30 says 20w40 and 20w50 are usable if it's over 68F. Nissan also said the same thing about 5w30 vs 10w30 that the Firebird said: 10w30 is fine above zero, otherwise 5w30.

If you think it's too cold to use 5w30 in your Subaru in Colorado winter, you can always buy M1 AFE 0w30.

The Subaru community seems to like Rotella T6 5w40, and Subarus are most popular where it gets really cold, so you should have no problem with your PYB 5w30.

Also, SP will likely have enough syn that the different between it and PP full synthetic in cold performance won't be very much.

That's actually a good point about so much of the turbo Subaru crowd loving 5w-40 (for whatever reason it didn't even occur to me until you brought it up)!
 
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