Viscosity Grade recommendation for Death Valley

[kschachn]

You just showed me you don’t know why engines idle high on cold start. They idle high bc of the amount of fuel that is injected in to the cold engine and it needs RPM to burn off or the engine would hesitate and run rough.

Actually the primary reason is to raise the EGT for the catalyst. But there are other reasons.

 

[Fahrvergnügen]

Actually the primary reason is to raise the EGT for the catalyst. But there are other reasons.

No! That’s a myth. I have been through god knows thousand of hours of manufacturer certifications and that is something talked about and it’s nothing to do with catalyst.

 

[Fahrvergnügen]

Actually the primary reason is to raise the EGT for the catalyst. But there are other reasons.

I’m looking for my book on that from nissan and BMW so I can word for word it.

 

[chris719]

No! That’s a myth. I have been through god knows thousand of hours of manufacturer certifications and that is something talked about and it’s nothing to do with catalyst.

No, it's not. It's for the cats. Plenty of BMW tuners delete the cold start cycle on modified cars and it does not exhibit any of the effects you mention.

 

[burbguy82]

Ultimately, every bit of heat in the engine comes from the combustion. But combustion temperatures is not the primary source of heat in the engine oil. And even if you struggle with that notion, RPM is not “ irrelevant” as you postulated.

I’ll place all of this in the same bin as the multi-page argument you made about LSPI.

No, work generates heat. And if you would read, we are not talking solely on engine oil.

 

[kschachn]

No, work generates heat. And if you would read, we are not talking solely on engine oil.

Yes the work from shear. Here is another discussion we’ve had on this topic. There are others.

In particular the post from @Bryanccfshr who knows more than I do.

https://bobistheoilguy.com/forums/threads/impact-of-towing-on-engine-oil-temperature.332688/

 

[AJB0009]

Okay, so if the coolant in your radiator is 200*F, it will be able to dissipate that heat much faster if it is 0 outside vs if it is 100. Correct?
What happens if you move from sea level to 10k feet?
Does the relative humidity percentage in the air have any effect? Let's say 10% (AZ) vs 90% (S FL)?

 

[burbguy82]

Yes the work from shear.

No work from energy, the heat that is generated is from energy....period, or are you an expert in physics too, and want to rewrite as you see fit? All the losses is a system manifest in output or heat, to the point, lower load (work)=lower heat

who knows more than I do

wow

 

[burbguy82]

Yep My truck has one big viscus clutch fan belt driven. When I had my 2004 nissan titan, I had a bumper pull travel trailer, weighing 7000 lbs, on the same grade that I explained earlier with my super duty, I wouldn’t tow in fifth gear so that truck turned 2500 rpm as well bc if you towed in overdrive, the temps would come up and it would gear hunt. So I would turn off overdrive climbing those grades in the titan and the fluid temps stayed the same.

Right, it is because more energy was able to go through the drivetrain to friction in the tires and road, due to the mechanical advantage of a lower gear.

 

[kschachn]

No work from energy, the heat that is generated is from energy....period, or are you an expert in physics too, and want to rewrite as you see fit? All the losses is a system manifest in output or heat, to the point, lower load (work)=lower heat

wow

So if you don’t like the second link, what’s incorrect in the first one I posted? In technical terms please, using your understanding of physics.

 

[SubieRubyRoo]

What generates heat?

RPM & friction.

 

[ripcord]

Uh, combustion creates most of the heat. Friction to a much smaller degree.

 

[OilUzer]

Most manuals specify a range of multigrade oils. Winter and summer oils are a thing of the past.

We have to consider CAFE driven recommendations! Which is to use your favorite xW-20 oil in every season! That's what 3 of our newer cars say (2 of them 0W-20 and 1 says 5W-20). So I am very well aware of what owner's manuals say these days in the US.

"A Thing of the past" or not, I rather use "summer oil" in the summer and winter oil in winter. And I think majority who are NOT part of the thin movement (i.e. those who prefer not to use the same thin viscosity grade for all seasons) will do the same. It's only logical.

Lots of people here are even using "summer oil" in winter.
Drop a 0 in front of your "summer oil", and you have your manly German 0W-30 and/or Euro 0W-40 for your winter.

So nothing is "a thing of the past."

 

[kschachn]

Uh, combustion creates most of the heat. Friction to a much smaller degree.

Not in the oil it doesn’t. Do you have anything to show that?

 

[Haakon]

Yes, we're aware of what it is and we don't care. Anything around the Australia region is Kiwiland.

ah yes, there's that wonderfully broad understanding of the world at large that Americans are so famous for

 

[I<3oil]

ah yes, there's that wonderfully broad understanding of the world at large that Americans are so famous for

There's that horrible language comprehension that people down under are famous for

 

[ripcord]

Not in the oil it doesn’t. Do you have anything to show that?

What heats the coolant that circulates inside passages in the block and heats? Combustion heat. What else is constantly circulated through passages in the the block and heads? Hint, oil. Oil is also splashed (and in some engines even sprayed) on the bottom of the up to 600F pistons as their primary source of cooling. Friction does contribute heat but it's not the majority.

 

[edyvw]

Okay, so if the coolant in your radiator is 200*F, it will be able to dissipate that heat much faster if it is 0 outside vs if it is 100. Correct?
What happens if you move from sea level to 10k feet?
Does the relative humidity percentage in the air have any effect? Let's say 10% (AZ) vs 90% (S FL)?

From sea level at which temperature? At 100f? Yes, it is harder to cool off at 100f at sea level than 0f at 10k ft. This is where if cooling system if compromised, can fail at 10k

At sea level at 100f and 10k at 60f? 10k by far harder to cool off.
I have seen cars from TX and AZ here at local track going in limp mode while according to owners they don’t have problems on tracks in summer in Dallas, Phoenix etc. Our track is between 4,900 and 5,100ft and can get 105f in the summer.

 

[drtyler]

It's hard to understand how blocks made in Japan for the LX and blocks made in the US for the Tundra have the same "cleanliness" problem. It's hard to square the explanation given with what is known.

If the machines / robots are exactly the same and have the same programming, then it does make some sense.

But it might a while before we know if its the whole truth.

 

[Fahrvergnügen]

No, it's not. It's for the cats. Plenty of BMW tuners delete the cold start cycle on modified cars and it does not exhibit any of the effects you mention.

Like you said the car is TUNED. It’s not the factory mapping and has been modified.