Delvac 1300 10w30 is one, dual rated sn and has a hths of 3.6
https://www.mobil.com/en/lubricants...cants/products/mobil-delvac-1300-super-10w-30
What is considered a respectable HTHS?
- Thread starter Carlostrece
- Start date
https://www.mobil.com/en/lubricants...cants/products/mobil-delvac-1300-super-10w-30
Yet we clearly know that cylinder wear decreases as temperatures increase, to a point of course. We also know that Nikasil/Nicom and certain composite cylinder liners behave very differently than iron, spray iron or compacted graphite iron liners. And the ring choice matters too. Chrome faced rings vs moly vs DLC, and even plain old iron rings.
The situation is not all that simple. I guess BITOG would consider me a 'thickie'. Mostly due to my race car and FL experiences. But it is also true that many modern engines control cylinder temperatures and oil temperatures well enough to utilize lower viscosity oils and achieve stunning long life with low wear rates.
I am using 5W-30EP M1 in my tuned AJ126 (supercharged 420HP 3.0L) Jaguar, up from 0W-20. If I move to the 475HP setup, I will step up to a 40 viscosity. The cylinder liners are iron and the rings are chrome nickel alloy. Neither of which are known to wear fast, even with the 0W-20. The rod bearings and cam followers (DLC coated shims) are another story.
Last edited:
Of course materials play a role in wear rates ... that's why certain engine components are made of certain materials, heat treated and coated accordingly to mitigate wear when lubrication alone can't prevent excessive wear rates. Engineers have gone deep down that rabbit hole as thinner and thinner oils are specified. More viscosity will always give more film thickness and more wear protection regardless of what the material is on each side of the oil film between the moving parts. That's the whole basis of Tribology that revolves around viscosity.
The wear rate vs oil viscosity info I posted is on the same engine with the same materials in all engine components, so regardless of the materials it clearly shows the impact of the oil viscosity on wear rate. The physics of lubrication between two moving parts will never show wear decreases as viscosity goes down, all other factors held constant.
As pointed out previously, keeping a very thin KV100 oil cooler in temperature keeps the viscosity up. It's no different than using a thicker oil at a higher temperature. It still comes down to the operating viscosity between the moving parts, regardless of how you get the viscosity.
I wouldn't use xW-20 in anything with that much HP, maybe unless I never went past 20% throttle. I put xW-30 in everything specifying xW-20.
Last edited:
Carlostrece
$100 Site Donor 2025
It was heading there for 10-15 years or longer, IMO. I think we fully arrived at least 5 years ago.
I like my 97 Buick, but if I ever buy a newer car I'll look for an EV.
I don't prefer EV over an old school gas engine with port injection, roller cam, and timing chain; but I do prefer EV over a gas engine with direct injection or timing belt. Then consider the thin oils specified for newer gas cars and possible concerns with that. For me, I say "no thank you" to modern gas engines, IMO.
Last edited:
You can put whatever viscosity in them you want - easy fix.
Carlostrece
$100 Site Donor 2025
True, but there's no easy, good fix for direct injection AFAIK. Maybe there is and I just don't know about it. I'm aware of several fixes, but they all involve hassle and/or expense and are bandaids that don't fully fix the issues.
There's no fix for a timing belt, except to replace it on time and hope it doesn't break before then. I suppose a frequent visual inspection could be advised. But all this is a hassle and expense, even if you do it yourself. If you hire it done, then it's still a hassle and is a greater expense.
Buy a vehicle with dual injection (direct + port) and with a timing chain. I don't think many engines use timing belts these days.
Carlostrece
$100 Site Donor 2025
Dual injection is a reasonable technical solution in some ways, but it bloats the cost of the vehicle and maintenance costs, IMO.
What costly maintenance is involved with a dual injection system?
Carlostrece
$100 Site Donor 2025
It's a more complicated, expensive system to build, which is one of the factors bloating new car prices.
With dual injection you have twice as many injectors to maintain or replace, and I've read that direct injectors are more prone to clogging than port injectors. Also, wouldn't a dual injection system still suffer from some fuel dilution due to the DI portion?
Am I missing it, but where is that HTHS 3.8 listed?
It is not listed by Quaker State, but a member here posted it in a thread, I will see if I can find the Link and then post it here for you.
What is the HTHS Number of quaker state euro 5W-40 motor oil
The HTHS (High-Temperature High-Shear) viscosity of Quaker State Euro 5W-40 motor oil is approximately 3.88 mPa·s. That’s a solid number for a Euro-spec full synthetic oil, indicating strong film strength under high stress and temperature—ideal for performance engines and extended drain intervals.
Last edited:
thanks
DI injectors are not more prone to clogging.
Fuel dilution is a not a DI problem per se.
A dual system would probably run on PI under most low speed conditions which is where fuel dilution is probably most likely to occur (i.e. short tripping). Toyota and VW have been using a dual injection system for years.
Injectors really aren't a maintenance item. They never have been.
To clarify, the viscosity (regardless if it's KV100 or HTHS) isn't really related to the "film strength". Lots of articles use the term wrong. The "film strength" is a result of the AF/AW additives and the resulting tribofilm the oil creates on surfaces. The film strength is a measure of the oils ability to mitigate wear when the film thickness (which a function of the oil viscosity) is too low and can't keep moving parts from rubbing on each other. Film strength of the oil plays a major role in boundary lubrication. Film thickness due to viscosity is the major player in mixed and hydrodynamic lubrication. As usual, more viscosity means more MOFT film thickness and more wear protection by giving more parts separation.
Viscosity creates a film thickness between moving parts to help prevent rubbing, friction and wear, When the speed of the moving parts and/or the viscosity becomes too low and parts start rubbing on each other more, then the film strength (AF/AW tribofilm) kicks in to minimize friction and wear.
https://www.machinerylubrication.com/Read/30835/lubricant-film-strength
I am a big HTHS and NOACK Guy, but that does not matter here to a certain extent. Let's see if we agree on this, at a certain Temperature I want a Viscosity Number of 10, meaning the highest oil temperature that I see where I can record the temperature. I did this with my lawnmower engine with a thermal probe, and I got a temperature of 230 F when I turned the mower off, the Infrared gun pointed at the drain plug and oil filter does have its limitations.
The HPL CK-4 10W-40 that I am using in the Mower with me doing the Calculator thing tells me I am good up to 242F, the Shell Rotella T5 10W-30 that I broke the engine on is about good to 226F
I am using Mobil 1 ESP 5W-30 in my car and when I put the numbers in, I get 226F, let's be realistic, this is a water cooled engine and my oil temps are probably only about 210F during the summer. The Quaker State Euro 5W-40 would be good up to 237F, here is the kicker, this oil has a NOACK of 5.7 versus what I am using, meaning the ESP 5W-30.
I am thinking, and you can correct me, let's forget the HTHS Number, well let's point it out 3.5 versus 3.8, not a big difference. The NOACK number can be debated, but the Quaker State Euro 5W-40 will more than likely protect the engine better than the Mobil 1 ESP 5W-30? To clarify, I need to use up my ESP 5W-30 before going to a thicker oil. Am I on the right track with the Engine Oil Temperature thing to a certain extent?
Can you link to the source please instead of copying and pasting?
No problem!
Carlostrece
$100 Site Donor 2025
That is excellent and would be very helpful info if I wanted a 5w40. Do you know the HTHS for:
Quaker State Euro Full Syn 5w30
Quaker State Ultimate Protection Full Syn 5w30
Knowing those would be very interesting and possibly useful to me.
What's the story on that engine failure?
Yeah, a HTHS difference between 3.5 and 3.8 cP isn't huge, and HTHS of 3.5 cP is pretty good for a 5W-30 and would work fine for street driving, but as usual the higher HTHS will give a bit more protection headroom. The lower Noack is a bonus too.
It's one way to look at it, and you're basically looking at what you believe will be the highest oil temps and shooting for a KV100 that's going to keep the viscosity 10 cSt or higher. As the max oil temp goes up, then to maintain a safe level of viscosity the KV100 & HTHS viscosity will also need to go up. Running a xW-20 at say 250F max for instance would be running the MOFT on the ragged edge IMO with not much if any protection headroom.
Similar threads
