I will say in my 15' LX, when I've gone 10,000 miles on an oil change interval, there were virtually no detergents left. As in less wear protection. I send mine off to Blackstone Labs every oil change as I bought it with 89,000 miles. I've tried 5k, 7,500 and 10k intervals. From a an objective scenario it seems 7,500 would be my upper limit. 5,000 shows very little breakdown and has some room to run. That is running 0W-20 Mobil1 synthetic.
Just some food for thought.
I have no doubts about what you are seeing also. But that comes down to mass produced oil blends. More on that lower in this post.
Can you elaborate more on choosing a lower hths oil?
In my opinion, viscosity rating and cold weather pour point are very simple ways of trying to kinda guide armatures to generally what they need. I would recommend looking at HTHS and MRV. HTHS is (and I’m going to use wrong term and crazy simplify this, so please no one bit my head off) how hot you can push an oil before it starts to breakdown. MRV is how easily an oil can push though little spaces when cold, under load. Like in an engine.
When I first read that post, I was thinking he meant NOACK
HTHS didn’t register.
Yeah idk why you would want lower HTHS.
Because you want the oil to quickly cool parts, and sometimes, a higher HTHS will hinder that. Extreme example, 2,000+ hp drag production cars. They run 5 weight oil in their motors because, the oil is cold and now acts like a much thicker oil. So back to a 3UR, most of there engines are daily driver, short trip vehicles. If I wanted to reduce wear, I would run a “thinner” oil that would move faster around the ringer when cold, and heat up quicker. As the engine will turn off, and cool soon after start up.
HTHS is not viscosity though. It’s related but if I had two oils exactly the same except for HTHS, I’d always go for the one with higher HTHS.
Totally agree. If MRV is appropriate for the starting temp range, and I have a nothing special, normal production motor, like a 3UR, I’d take .1 HTHS more. But yeah, 100% agree with you.
Sorry for late responses, I’m in and out a lot. And I apologize that this post is all over the place. I’m trying to shove a ton of engine tear down experince into a fast to read post. I don’t want to ruffle any feathers also, so don’t take me too seriously. If you disagree, no worries, we can still be friends. But I worry it will be awhile for me to respond again.
So, I would recommend getting away from worrying about viscosity. I really would. Look more into VII (viscosity index improvers). In this very thread, I used to run Redline 0W-30. Not anymore. I have found from pushing some of these motors overseas that keeping the oil from breaking down when running long intervals, that cheap shelf, wide range oils like 0W-30 breaks down faster than I want. Because it is loaded with VIIs instead of just using higher quality base oil. Cost reasons.
Also, bulk oil that I see everyone recommend, if you take two bottles of exactly the same oil from the shelf, and send those off for analysis, you will find that they are not always the same. Just like anything, if you make (blend) something fast, to get costs down, you will get a wider “acceptable” range.
Instead of making a long, drawn post even longer. Check out High Performance Lubrication (advlubrication.com), and while mostly overkill, their No VII, in 5w-20 will give more “protection” than anything anyone on here is using and handle high heat and heavy towing better than anything you are getting at Walmart or Amazon. Bold statement, I know. If you will be starting your motor in freeing temps, run their Premium Passenger Plus 0w-20. If you want to run a 30 weight, go for it. Mind you, the weak link in a 3UR is not the low tension piston rings, cylinder walls, or valve train. It’s the timing chain tensioners. Toyota got to four different versions of the chain tensioner design before they stopped making that motor. So is the tensioner design finally fixed or did they just stop there? Because when you get to four redesigns, I know think that maybe you needed five or six designs. Or… the chain is just way too long and tensioner #1 just will have a shorter life span.
Anyway, I’m not saying a 0W-30 is necessarily bad. Just that they usually need a lot of VIIs to get that, and those breakdown faster, and you will probably find varnish in your motor. If you are towing heavy up mountains, and camping overnight in freezing temps, well, 0W-30 sounds about right. But I don’t think I would use a 0w-30 when summer came around if I had the choice, especially if I was using sub $40 for five quotes bulk oil and running 5,000 mile oil change intervals.
I probably should have hit on “oil film thickness,” but really, that’s not a thing that will present itself unless you lost your radiator and still wanted to PUSH IT TO VALVE FLOAT!!
So yeah, all in all, if you are going to run 5,000 miles OCI, oh run whatever you want with a good filter. 3UR is going to a half million miles as long as you replace chain tensioners somewhere in there (which will also get your cam towers and timing cover resealed in the process). Want to run in 110+ºF while pulling a trailer, off road, in low range, while drunk, doing donuts, screaming Toyoda! Maybe HPL oil made of much more expensive base oils and additives that are blended to such are tighter tolerance time after time, with no VIIs to break down, and if you secretly want a diesel, then run a higher HTHS.
