15w50 and ambient temperature

What temperature would a 15w oil start to become dangerously thick? In another thread i told about taking the plunge from 10w30 to 15w50 to see what effects it has and to see if it fixes a few issues My question is, would i be able to use it year round? Where i live it only gets to about freezing point a couple of times in a winter and hardly ever much below. I sometimes take roadtrips to the snow where it can get much colder Would i need to change to 10w40 or would 15w50 still be okay?
 
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238
Location
NY
15W is too thick at startup for most applications in even just moderately cool weather. Slow to pump at startup. This can increase motor wear. A 0W or a 5W is usually a better choice.
 
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2,035
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Ontario, Canada
Originally Posted By: 19jacobob93
Would i need to change to 10w40 or would 15w50 still be okay?
' One has two options in this case: a) freak out about it being too thick due to an unproportional disparity between casual imagination and reality b) observe the CCS/MRV viscosities and borderline pumping temperature
 

19jacobob93

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735
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Gold Coast, QL, Australia
I would like to try 5 or 10w50 but they are very expensive Im thinking maybe run the 15 through summer as it never drops below 20-25c at night (think florida type weather) If i start to get any noises or adverse effects as we head back into winter ill probably change back to thinner
 

19jacobob93

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735
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Gold Coast, QL, Australia
Yep! The manual recommends 10w30 and this is also written on the filler cap but its a very old debate. In the 1994-1998 model, the one before mine they recommended 15w40 and this had the exact same engine only with a different head gasket and altered ecu. When the new model was introduced in 1998 they recommended 5w30 as the movement towards thin started, but quickly taxi companies were finding premature engine wear and lifter failure, so Ford issued a statement telling people to change back to 10w30 or 15w40 and this completely stopped the problem Just seems like these engines hate thin oil, as they were a bit long in the tooth at the time being designed for 15w40 a decade earlier Mine has always had thicker oil in but i switched to 10w30 last year because thats what it recommends, but all of a sudden all of my lifters are shot! Cant be a coincidence so back to thick i will go frown
 
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3,117
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Virginia
I've used 15W-50 M1 down to about 20F in my big block Suburban w no issues. It always flowed fast for me, I just let it warm up a few minutes before putting it in gear. It definitely flows faster than 20W-50 dino which I've seen people use year round for hundreds of thousands of miles in my area - N Virginia. If you routinely get below 20F, I'd probably use a 0W-40.
 

19jacobob93

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735
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Gold Coast, QL, Australia
Originally Posted By: bigt61
I've used 15W-50 M1 down to about 20F in my big block Suburban w no issues. It always flowed fast for me, I just let it warm up a few minutes before putting it in gear. It definitely flows faster than 20W-50 dino which I've seen people use year round for hundreds of thousands of miles in my area - N Virginia. If you routinely get below 20F, I'd probably use a 0W-40.
Okay that's comforting news i guess! Tried 20w50 once and it knocked like a Jehova's witness in the mornings so i dropped it straight out. My dad used 40w70 (please don't kill him) in a mitsubishi v6 before and it ran perfect haha Yeah won't be getting that cold very often! Maybe once every 2 years if ever so i'm excited to try 15w50 now smile
 
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24,475
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Dallas,Tx USA
Run the 15W50 year round,you'll be fine. I started my car on a -2F degree morning (car was even sitting outside ungaraged all night) with Valvoline dino 20W50 in it,and she started right up as soon as I turned the key and purred to life. My car actually specs thicker oils and warns against using thinner oils.
 
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238
Location
NY
A 0W-40 is not a thinner oil. At running temps it is a true 40. Only during cold startups is it a 0W and that is not too thin even in Florida. It pumps a lot faster which is a good thing, really. Same goes for a 5W. Remember the W rating is not the same as the running temperature rating. A common misconception. A 0W at its rated temp is actually thicker than a 40 weight oil at its rated temperature. Different rating scales.
 
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17,301
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OH
According to the OM of my old BMW, a 15W-50 is fine down to -20C, which is about -4F. I doubt that you see that kind of cold where you live.
 
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28,123
Location
Regina, Saskatchewan, Canada
Originally Posted By: fdcg27
According to the OM of my old BMW, a 15W-50 is fine down to -20C....
My old Audi's manual was much the same. I didn't bother keeping 15w-40 in there to that temperature point, but it was certainly allowed.
 
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43,670
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'Stralia
There's millions of Falcon bottom ends made it through their life with 20W, given Gold Coast, you'll be more than fine with 15W... Not that 15W50 would be my first choice of oils, but won't hurt a thing.
 
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496
Location
Australia
Originally Posted By: 19jacobob93
What temperature would a 15w oil start to become dangerously thick? In another thread i told about taking the plunge from 10w30 to 15w50 to see what effects it has and to see if it fixes a few issues My question is, would i be able to use it year round? Where i live it only gets to about freezing point a couple of times in a winter and hardly ever much below. I sometimes take roadtrips to the snow where it can get much colder Would i need to change to 10w40 or would 15w50 still be okay?
15w-50 or 10w-40 will be fine for your occasional trips to the snow and all year round. If it was my car, I wouldn't go below a 10w-xx, and would even seriously consider a 20w-xx grade in a good quality synthetic.
 
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17,301
Location
OH
Did your Audi's OM also recommend 20W-50 for the warmer months? My BMWs OM does, as though that would ever really be needed.
 
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28,123
Location
Regina, Saskatchewan, Canada
Originally Posted By: fdcg27
Did your Audi's OM also recommend 20W-50 for the warmer months?
It sure did, although I didn't bother with that, either. Having never seen oil temperatures above around 95 C, even with extended periods of boost, I had no reason to try something that thick. Here's the chart. I was off by 5 degrees; 15w-40 was only good to -15 C. wink
 
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