10w30 for a high mileage VQ35?

[Sierra048]

Great info and I appreciate the input.

I agree KCJ about the old wives tales. It's just with my kind of luck, this would have been the one that turned out to be true (about having to stick with HM oil once it was used). My wife just changed jobs and will be working about four miles from home. Think I'll be going with a full synthetic for her next oil change. For me and the Jeep, good old PYB. Also after my last post I found a thread started yesterday on here about age vs. mileage. Good reading. Thanks again to all.

 

[steveh]

Rotella T5 10W30

 

[Merkava_4]

Originally Posted By: mclasser
I also have a VQ35. Unless you're burning oil, there's no sense in switching to a higher weight. No reason to rock the boat if 5W30 has worked fine for 138K miles.


10W-30 is only slightly thicker than 5W-30 when cold. At operative temperature, they're the same thickness. 10W-30 is more resistant to shearing and therefore more durable than 5W-30. You're getting a tougher oil with 10W-30.

 

[Nickdfresh]

Originally Posted By: Merkava_4


10W-30 is only slightly thicker than 5W-30 when cold. At operative temperature, they're the same thickness. 10W-30 is more resistant to shearing and therefore more durable than 5W-30. You're getting a tougher oil with 10W-30.


Not nearly as true as it used to be. The newer base oils are much more shear stable and I think some here have stated that SN rated 5W-30's tend to use better base oils than their 10W-30 counterparts.

I have nothing against 10W-30 though and will use it in my beater the next oil change. I think its place is mainly to reduce moderate consumption...

 

[vq35de_touring]

Originally Posted By: Volv04Life
Ive always ran my altima on 5w30 since new. it has 138000 on it now. Im wondering if I need to be using 10w30. All the oil selectors on the internet and in stores say 10w30 but the manual says 5w30. Im confused. Have I been using the wrong weight all along or is the 10w30 just for high mileage?


I have two different vq35de engines in different applications. Both of them allow 5w-30,10w-30, and all the way up to 10w-40. Just pick your oil weight based on your climate.

Now in the vq35de's sport oriented apllications(350z) it has been established that they prefer a 40 weight or heavy 30 weight.. Hence I use M1 0w-40, one of the best oil choices available.

 

[aquariuscsm]

How about Syntec 5W40,Synpower 5W40?

 

[KCJeep]

Originally Posted By: Nickdfresh


Not nearly as true as it used to be. The newer base oils are much more shear stable and I think some here have stated that SN rated 5W-30's tend to use better base oils than their 10W-30 counterparts.

I have nothing against 10W-30 though and will use it in my beater the next oil change. I think its place is mainly to reduce moderate consumption...


True. My Jeep buddy on here just posted a second UOA for PYB, a former one being 5w30 the second 10w30. We were curious about shear as the Jeep 4.0 will knock a 5w30 down close to 20 grade around 3k or a bit more. When I figured in his half quart of make up oil in the 10w30, the end result was essentially the same between the two. I was surprised.

I still like a thicker 30 though, and won't run 5w30 in my Jeep more than 3k due to shear concerns but at least one big name 10w30 was no better than it's 5w30 counterpart. Might as well run the 5w30 then.