And they won't sell many vehicles if their engines have a reputation to fail before the competition.
The truth about oil change intervals and analysis
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*Gm 3.6l and ford 3v 5.4l have entered the chat*
OK, let's put it another way..... What's the viscosity, (flow), difference between the 2 at the temperatures that I indicated? Someone somewhere must have tested this.
I'm guessing that 0W-16 at -20F would flow a lot slower, (hence thicker), than 0W-40 would at 65F. But I'm just guessing.
And if that's the case, one could assume that cars in frigid Winter climates would experience more startup wear over time, based on the simple fact the oil thickens up far more, thus taking longer to reach critical engine parts.
If I had some 0W-16 I would test this by putting some in the freezer, and leave some 0W-40 outside. (50F to 65F). Then see what's what. But I have zero use for any.
And the Hyundai/Kia theta engines. They are disparaged. From what I hear it a metallurgy thing. Not sure if changing the oil at 3000 miles vs 7500 miles will make a difference in these engines.
If lowering the OCI would make a difference on the Theta-ii engines we'd see Hyundai making new recommendations as part of the recall. To my knowledge that hasn't happened. Still 7500 miles (at least on the NA 2.5L engines in the US)
There have been various instances where a manufacturer has reduced the OCI mileage (i.e. 7500 miles to 6000 miles). But those seem to be related to handling either fuel dilution or that the engine burns some oil and to provide assistance to consumers that just don't check their oil and not the oil itself.
At 80 years old these are my considerations. Because I don't have a garage.
Changing oil when it is 20 degrees outside.
Changing the oil when it is raining outside.
Changing the oil when it is sunny and reasonably warm not hot outside.
Number three has been the winner every time since I was 40. April and October is the fix for this dilemma. Yes I over maintain but then I drove my last car for 16 years. I change my oil for less than the oil store with better products and cheaper. Oh and I know it isn't over or under filled!
Changing oil when it is 20 degrees outside.
Changing the oil when it is raining outside.
Changing the oil when it is sunny and reasonably warm not hot outside.
Number three has been the winner every time since I was 40. April and October is the fix for this dilemma. Yes I over maintain but then I drove my last car for 16 years. I change my oil for less than the oil store with better products and cheaper. Oh and I know it isn't over or under filled!
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I guess they need to start thinking about piston rings
Sure but again flow is not all that relevant. If the oil can be pumped it will flow. It only needs to be able to flow to the oil pump pickup. It’s why those freezer tests are largely irrelevant to engine operation.
People like the looks of them because they are visually impressive but again not relevant. The winter rating which represents pumpability is what’s more relevant.
You're missing the point. Yes, it will flow, but how quickly. The thicker it is at startup, the harder it is to pump. And the harder it flows, the slower it will reach the already moving parts. Which is where most say the bulk of engine wear happens.... At startup.
In a frigid Winter climate the whole concept is to balance the viscosity to allow for easy enough starting and sufficient cold flow, but still not be too thin at operating temperatures that are often over 200F.
With that said, back to my original question. On the low temperature end of this, which is thicker.... Or, which will flow easier and quicker. 0W-16 at -20F, or 0W-40 at 65F? Obviously at operating temperature the 0W-16 will flow easier, (perhaps too easy), because it is much thinner.
Billt460….
That 0w will be pumped just fine at -20 F…
Just like the 0w40 at 65 F.
And the difference in time will likely be negligible between the two…
Now… I hear you make really good waffles…
What the thickness in cSt is your batter at 72 F ?
The oil pump is constant volume x rpm, it either flows or not.
"Speed" will be the same. Return speed from head to sump might differ. And colder temperature might result in more wear, but that has more to do with metallurgy then specific oil in this case, since both are 0W.
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In your example, both 0W-16 and 0W-40 are 0W grade oils so they will both basically pump and flow the same at cold temperatures. 0W is the "thinnest" W rating in SAE J300. The engine manufacture recommends a W rating for a "down to" x deg F cold start. You obviously wouldn't want to use a higher W grade for cold temperature start-ups that it's not rated for because of the possible lack of flow to get to the pump pickup and pump inlet which is a pumpability factor. Once the oil gets to the PD pump, it will force the oil to all parts in the oiling system that are force fed by the pump. It will take more force to push thick oil through the system, and that's why the oil pressure is high with cold thick oil. If the pressure gets too high, the pump will hit pressure relief so it doesn't literally blow something up with excessive oil pressure. The lower the W rating, the better the oil will flow to the pump pickup and will also flow back to the sump and get to any parts that are "splash" lubricated instead of force fed by the pump.
That's the whole reason for multi-viscosity grade oils. W rating for the cold starts and the KV100 rating for operating temperatures.
0W grade is 0W grade, so in your example both 0W-16 and 0W-40 will both flow and pump basically the same at cold temperatures. If you really want to split hairs on a W rating between oils, then you'd have to look at the oil's spec sheets and see what the actual CCS and/or MRV viscosity is and compare them to each other. In your example, the 0W-40 will be thinner at 65F than the 0W-16 is at -20F because they are both a 0W "winter" grade per SAE J300. If both the 0W-16 and 0W-40 were at -20F and the engine was started, both would basically flow and pump the same, and as the oil warmed up from -20F to 212F (100C) the 0W-16 would be a 16 grade and the 0W-40 would be a 40 grade. Each would thin down from whatever their viscosity was at -20F to their KV rating at 100C (212F) viscosity.
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The PF "cold oil races" give a slight indication on how the oil would flow into the evacuated cavity due to the pump shown in Zone 1 in the figure in my previous post. If the oil is so thick that it's like molasses and barely moves under the force of gravity, the pump could suck air in Zone 1 and then that causes a pumpability issue in the pickup tube. If the oil can't get to the pump inlet through the pick-up tube (or there's lots of air pockets) then there will be a lack of lubrication. If the W rating is correct for the start-up temperature, then there shouldn't be any problem. Don't try 20W-50 in a -25F start-up for instance.
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The oil, I suppose, is easy, but I am not seeing how premium fuel is going to help the problem.
Thanks! Please note that BITOG would be finished with a strict no "Discussed previously" policy. I tend to repeat my mistakes.
Sorry should have dropped a search link: https://bobistheoilguy.com/forums/search/2849129/?q=enrichment&c[users]=Pablo&o=date
That is what I'm more or less referring to. You can pump anything through anything with enough power. Hell, today they can pump concrete over 1,000 ft. high when they build high rises.
But if the oil can't flow to the pump fast enough, it will suck wind, not oil as you pointed out. If it's -20F even 0W-16 is not going to flow like it would at room temperature. Nowhere close.
I remember there was a Oldsmobile V-8 that had issues with oil not being able to return to the pan fast enough at high RPM's. This would in turn cause the oil pump to suck air, because all the oil ended up at the top end.
My neighbor had a jet boat with that Old's V-8 engine, and he said they had some kind of fix, (kit), that would remedy the problem. It was really bad with boats because they ran at very high RPMS for a long time.
And boat engines run a lot cooler, because most of them have water cooled manifolds, along with a lake full of cool water flowing through them.
Put that same engine in northern Minnesota in January at -20F, and it's not going to matter much what you put in the crankcase, it's not going to flow back to the bottom as fast as it can be pumped to the top end. At least not until some heat builds up in the motor.
So what? Most 0W pumps (MRV) down to -40F or close to it. CCS is done at -31F.
*** are you on about?
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