Lowest Temp For 10W Dino ?

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3,121
Location
GA.
What is the lowest reasonable temp you would run a 10W 30 or 40 weight conventional oil ? ...I have heard for a conventional 10W any where from 0 degrees F. to 32 degrees F . but perhaps it will even pump adequately below 0 dgrees F . ? My main area of interest (based on where I live) is that +0 degrees F and above . for 10W conventional. ... Your thoughts and experiences ?
 
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418
Location
BC, Canada
1) I always used 10w30 in my first car (1970 LeMans, over 30 years ago) year round. Back then it was the only light multi-grade commonly available. Temperatures got down (and still do) to -30C (-22F) regularly. Sold the car at over 100,000 miles motor was mint. 2) Last winter, my 2006 Sierra accidentally got caught out with 10w30 in the crankcase all winter (I did not put on the anticipated mileage that previous summer), same temperature extremes. It was fine. I did not like doing that (10w30 in the winter) but it was what it was. Where you live 10w30 will never give you a cold flow issue. Having said all this, personally I am a big 5w30 advocate (or lighter i.e. 5w20 if the manufacturer approves) for all year operation. I just have some 10w30 in my stash to use up. I plan to use 10w30 VR1 for my Chevelle if it is ever on sale, right now I use T5 10w30 in it but to the point of your post, I do not operate it below 40F generally.
 
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1,019
Location
Va
Subaru spec'd my legacy to ~4*F on 10w-30. I have run a synthetic 10w-30 over the winter previously, and didn't notice any starting problems down to 15*F. I tend to stick to 0w-40 or 5w-40 year round now. If I got a screaming deal on a 10w-30 I like, then I wouldn't worry about it for where I live. Just bought a 2001 land rover discovery, and considering a HDEO 10w-30 like T5 for the over the winter fill. It's got delvac 15w-40 in the sump now.
 
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8,051
Location
Michigan
SAE J300 specifications for a 10W oil require that it pass the cold pumpability test at -30C with a viscosity less than 60,000 cP. I wouldn't feel bad about using a 10W-oil at temperatures down to -20F.
 
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16,279
Location
N.H, U.S.A.
I don't start the car or go out of the house if its under -15degF. BTW, those pumpabilty spec deteriorate with oil age. Beware of fresh oil spec being applied to used oil. Your 3K mile used oil VERY likely wont pass a few new oil certification spec. And definitely not cold pumpability.
 
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5,928
Location
Waterloo, ON
Originally Posted By: ChrisD46
What is the lowest reasonable temp you would run a 10W 30 or 40 weight conventional oil ? ...I have heard for a conventional 10W any where from 0 degrees F. to 32 degrees F . but perhaps it will even pump adequately below 0 dgrees F . ? My main area of interest (based on where I live) is that +0 degrees F and above . for 10W conventional. ... Your thoughts and experiences ?
I used 10W30 Dino in -40 temps for a whole week with no issues. That was back in the 80's though
 
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13,118
Location
Indiana
IIRC, my OM says 10w30 is good for 0*F and up. I ran 10w30 last winter when it was -25*F and that was a mistake. I didnt feel as bad for my engine as I did my battery and starter, but I imagine it wasnt the best on anything.
 
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S California
"I used 10W30 Dino in -40 temps for a whole week with no issues. That was back in the 80's though" Beyond not starting or killing the starter or batter how would you know if there was excessive engine wear because the oil failed to perform in cold weather?
 

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46,228
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Ontario, Canada
Originally Posted By: Bluestream
Originally Posted By: ChrisD46
What is the lowest reasonable temp you would run a 10W 30 or 40 weight conventional oil ? ...I have heard for a conventional 10W any where from 0 degrees F. to 32 degrees F . but perhaps it will even pump adequately below 0 dgrees F . ? My main area of interest (based on where I live) is that +0 degrees F and above . for 10W conventional. ... Your thoughts and experiences ?
I used 10W30 Dino in -40 temps for a whole week with no issues. That was back in the 80's though
With a block heater? That is 5 degrees below the MRV temperature...... It was probably jelly.
 

ChrisD46

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3,121
Location
GA.
The question is for my old '95 jeep 4.0L engine ... I'm good with running 10W30 (recommended) in the Spring thru Fall OCI's - was debating on whether to run 5W30 dino just for the Winter fill ...Not sure how the old jeep 4.0L will do on all 5W30 dino or if I should split a 50/50 mix of 10W and 5W of the same brand dino just for the Winter ?
 
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8,051
Location
Michigan
If you have 5w30 already, just run that in the winter. It's not costing you any more money since you already have it. You're just using it to the best advantage. I wouldn't recommend doing a 50/50 mix of 5w and 10w, though. Nobody seems to be able to predict what cold pumpability standard a mix of W-grades will give.
 
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8,146
Location
Mahzurrah!
Originally Posted By: ChrisD46
The question is for my old '95 jeep 4.0L engine ... I'm good with running 10W30 (recommended) in the Spring thru Fall OCI's - was debating on whether to run 5W30 dino just for the Winter fill ...Not sure how the old jeep 4.0L will do on all 5W30 dino or if I should split a 50/50 mix of 10W and 5W of the same brand dino just for the Winter ?
I have taken to running 5w30 in mine just for the bitter cold months, runs great on it but I don't care to leave it in once it warms up. If your Jeep cranks well on the 10w30 I'd have no concerns about it either. I ran 10w30 in everything all year round for decades before I got bit by the BITOG disease and had no issues, maybe a few starts that were a little crankier than they had to be ha ha but that's it.
 
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5,928
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Waterloo, ON
Originally Posted By: OneEyeJack
"I used 10W30 Dino in -40 temps for a whole week with no issues. That was back in the 80's though" Beyond not starting or killing the starter or batter how would you know if there was excessive engine wear because the oil failed to perform in cold weather?
it was a 1980 Dodge van and it lasted to a ripe old age and ran great. No block heater at all...
 
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13,118
Location
Indiana
Originally Posted By: KCJeep
Originally Posted By: ChrisD46
The question is for my old '95 jeep 4.0L engine ... I'm good with running 10W30 (recommended) in the Spring thru Fall OCI's - was debating on whether to run 5W30 dino just for the Winter fill ...Not sure how the old jeep 4.0L will do on all 5W30 dino or if I should split a 50/50 mix of 10W and 5W of the same brand dino just for the Winter ?
I have taken to running 5w30 in mine just for the bitter cold months, runs great on it but I don't care to leave it in once it warms up. If your Jeep cranks well on the 10w30 I'd have no concerns about it either. I ran 10w30 in everything all year round for decades before I got bit by the BITOG disease and had no issues, maybe a few starts that were a little crankier than they had to be ha ha but that's it.
Didn't you say your jeep sheared the 5w30 to a 5w20 in about 3000 miles? I plan on running some 5w30 this winter, but it'll be a short OCI.
 
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28,123
Location
Regina, Saskatchewan, Canada
Originally Posted By: Bluestream
it was a 1980 Dodge van and it lasted to a ripe old age and ran great. No block heater at all...
I've said before that carbed engines very often started in weather far colder than was good for them, particularly considering what was in the sump.
 
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17,298
Location
OH
Originally Posted By: Garak
Originally Posted By: Bluestream
it was a 1980 Dodge van and it lasted to a ripe old age and ran great. No block heater at all...
I've said before that carbed engines very often started in weather far colder than was good for them, particularly considering what was in the sump.
Yep. A little fancy footwork on the loud pedal (the accelerator pump is your friend) and you could bring a carbed engine to life on the coldest morning even with very weak cranking. My personal best was about -25F with 10W-40. If you absolutely must have a running car in very cold weather, a carb beats FI, contrary to popular belief.
 
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8,146
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Mahzurrah!
Originally Posted By: dlundblad
Didn't you say your jeep sheared the 5w30 to a 5w20 in about 3000 miles? I plan on running some 5w30 this winter, but it'll be a short OCI.
Yep and mine is not alone I've seen that trend consistently out of the 4.0. So when I use 5w30 in the Jeep the temps are low and the OCI's short.
 
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4,652
Location
The Garden State
When I had my 1989 F-150 with the 4.9 six it spec'd 10W-30. With low teens and below conventional 10W-30 was not happy. I switched to Mobil 1 10W-30 synthetic and never had an issue with starting in real cold temps, it was nice and quiet and cranked much faster and started quicker. Whimsey
 
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9,125
Location
Marshfield , MA
You thin oil guys make me laugh. Ive started a BMW at 15 below with 10 w 40 in the sump. 20 w 50 will start down to 10 above. For the last 2 winters I've just thin the 20w50 with a pint of MMO. 10w30 at -25F in a carbed Willys. How cold does it get in GA? grin2
 
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