M1 0W40 in a VQ35

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M1 0W40 seems to be a highly-touted oil in Nissan VQs. I'm thinking about trying some for my next OCI. My I35 isn't a severe oil burner *knock on wood* but long road trips of 500+ miles do bring down the dipstick about a half-quart. Regular driving and commuting don't have much of an effect, though. The M1 would be left in for almost all of winter. How does 0W40 fare in cold weather? Temps here do get down to 10-15° (sometimes colder) at night in the winter. Will there be significant differences in cold starts versus the 5W30 syns I run now?
 
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The 0w implies better at cold temps than 5w. The difference may not be significant, but it certainly won't be worse.

I use Castrol Edge 0w30 in my older VQ30
 
Originally Posted By: slacktide_bitog
The 0w implies better at cold temps than 5w. The difference may not be significant, but it certainly won't be worse.
I use Castrol Edge 0w30 in my older VQ30

It will be worse, but not by much. The "0w-" part just means what the oil does in cranking at -35 degC, and -40 degC pumpability limits, and the "5w-" cranking/pumping is done at warmer temperatures than "0w=". At a relatively warm 10 degF, the 0w-40 is thicker than a full-syn 5w-30 is. Its confusing, but the 0w-40 does this trick by using more PAO, and ostensibly, more PPD and VII, chemistry.
 
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Originally Posted By: ExMachina
Originally Posted By: slacktide_bitog
The 0w implies better at cold temps than 5w. The difference may not be significant, but it certainly won't be worse.
I use Castrol Edge 0w30 in my older VQ30

It will be worse, but not by much. The "0w-" part just means what the oil does in cranking at -35 degC, and -40 degC pumpability limits, and the "5w-" cranking/pumping is done at warmer temperatures than "0w=". At a relatively warm 10 degF, the 0w-40 is thicker than a full-syn 5w-30 is. Its confusing, but the 0w-40 does this trick by using more PAO, and ostensibly, more PPD and VII, chemistry.


Yes, since 10F is only about -12C, we aren't down into the crossover point where the 0W-xx beings to thicken less than the 5W-xx lubricant, which is somewhere around -15C.

CCS and MRV can both be extrapolated backwards from their respective measuring points and halved at 5C increments. This is a "general" rule of thumb and works up to about -20C to -15C, somewhere in that neighbourhood. Just like the Viscosity Calculator doesn't work below 0C, extrapolating CCS and/or MRV backwards doesn't work at much above -15C IIRC.

Now, there are of course oils that, despite their 0w-xx designation, will still be thicker at their measuring points than a lighter grade in the next "winter" classification up. KrisZ and I were having a similar discussion a while back and he was able to find a 5w-30 that was actually thinner than the 0w-xx oil we were discussing at the time (which may have been M1 0w-40) going by the halving rule at the acceptable range of temperatures for the 5w-xx lubricant. It simply reached its gel point sooner, likely due to not having the same quantity of PAO.
 
The VQ is a good match for the Mobil 1 0W40, it doesn't really matter which flows better at low temperatures, it matters that the extra HTHSV would be useful.
 
My wifes '05 350z 58k mile has had a steady diet of Rotella 5-40 T6 for years. It only sees part year use of 5-6k miles and is changed before winter layup. All has been fine with that. Last year I found I was too low on Rotella and so ran with the Mobil 0-40 that I had. That's been OK and the oil pressure at hot/idle and through the range appears the same. However, this summer it's sometimes giving off a brief startup noise on the first start of the day that I figure is probably an oil pressure driven timing chain tensioner bleeding down over night. The car will get back to the Rotella this fall and we'll see if it goes quiet again or not.
 
Originally Posted By: Greasymechtech
I would use it year round since 10-15 degrees isnt too cold for a 0w40.

-40 isn't too cold for a 0w-40, either.
wink.gif
 
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