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

Messages
57
Location
Colorado
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.
 
Messages
11,147
Location
USA
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.
 
Messages
312
Location
Maryland
Well I know that with running Havoline 10w40 in a mid-70's Buick V8 and Chevy V8, I was able to start both when it was -37 Deg F (actual temperature) in the late 1980s in Wyoming one cold morning without any knocking or other difficulties, so I imagine that an SN+ or SP rated 5w30 Syn Blend shouldn't have any problems.
 
Messages
167
Location
Arizona
I started my 300ZX one winter when it was -4F with VWB 20W50 and it started and ran perfect.
Well in that case, then it will all depend on the design of the engine and/or the oil filter. OP did have a point about how the oil pump doesn't behave like a cup pouring cold oil like in the videos on Youtube. That freezing honey oil might be flowing better than we think when it gets past the pump. It definitely won't be flowing good enough to protect an engine if it's hot, but it's lubricating a cold engine nonetheless.
 
Messages
11,682
Location
Colorado Springs
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.
It is going to be fine. I used 15W40 conventional in Bosnian winters and it is colder there than here in CO.
 
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