I've studied over 550 Dmax UOAs from all over North America, from MX all the way up to the Circle. In just about every application you can possibly imagine. They are included in my UOA analysis study.
When it comes to cold starts,
IF you are in an area cold enough that every centistoke matters, I do whole-heatedly agree that a PAO 5w or 0w would be prudent. I already stated that previously. This will aid in cold cranking ability for the compression ignition service. I get that; you get that; Charlie gets that. Move on.
But NOTHING (and I mean absolutely zip, nada, zilch) indicates that the WEAR-RATES are affected in modern diesels by the thinner grades, and most certainly in particular the traits of a Dmax, which could not care less about what grade you use as long as it's a CJ-4 lube in an appropriate range.
I would challenge you to show me proof of your UOAs indicating that your use of 5w-40 develops wear-rates so positively altered that they are beyond statistical normalcy. Please tell me, right now, what your running mean and standard deviations are for your specific individual Dmax engine in your personal truck, so that we all can glean how well you understand (or don't ...) the concept of wear rates, variance and trending. Please post up all your UOAs so that we can see the true micro-analysis numbers of your data, contrasted to the mass-market macro formulations. My data is already posted for everyone to see; where's yours?
Originally Posted By: used_0il
Oh, and another consideration; XW40s protects against fuel dilution better than XW30s.
What? Where did that come from?
I call 100% bovine manure on this statement from you.
I will have to see CREDIBLE, SUBSTANTIATED PROOF before I believe that.
Really?
Seriously?
That's your story and you're going to stick to it?
Please explain how the thicker grade of oil can control the dilution effects from a leaking injector or the fueling in regen cycles? Please show me how those phenomenon are under the direct influence of the grade of lube. Please post up the direct evidence from credible article or SAE study that shows a 40 grade is somehow superior to a 30 grade in terms of controlling fuel dilution and it's effects.
All I can say is .... WOW .....
.