Viscosity Grade recommendation for Death Valley

[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.

And I’m guessing the TUNERS are the ones saying ‘it lights off the cats’ so that’s what everyone believes. Same people that say you don’t have to wait for the glow plug light to go off to start a diesel, or you don’t have to let diesels cool down after being driven. It’s people that don’t know or have been told wrong. I see it all the time especially with the CP4 pumps that have a bad rap from people that don’t have a clue

 

[chris719]

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

Nope, M2 CS Racing BMW customer cars have an abbreviated cold start cycle as well. Know what the difference between it and the street car drivetrain is? The cats.

My original point was that tuned cars with cold start cycle disabled don’t have idle problems. That is true. At least as far as modern gasoline cars are concerned. I never said there weren’t other factors but emissions are clearly the primary.

 

[Falcon_LS]

Air flow is one of the most important factors when it comes to the cooling system. I have experimented with different coolant concentrations in extreme ambient temperatures (120°F - 132°F) over the last couple of weeks, to include going as low as 20% coolant to 80% distilled water. While not the most accurate means of measurement, I have used OBD-II readings to measure both coolant and cylinder head temperatures and the difference I have noticed between a 50/50 ratio to a 20/80 ratio was about an 8°F drop depending on ambient temperature.

With that being said, even with a 20/80 ratio, being stuck in congested traffic is the single worst thing that can happen due to restricted cooler air flow. On Friday, I was driving along a freeway at 70 MPH with a coolant temperature of 222°F and a transmission fluid temperature of 188°F before the entire freeway came to a crawling halt for over 90 minutes due to a crash. This vehicle is equipped with a custom, all-aluminum radiator with increased capacity. With an ambient temperature of 127°F, it didn't take long for the temperatures to start creeping up with other heat sources (vehicles) around. In about 20 minutes, my coolant temperature went up to 236°F and TFT went up to 248°F. I was able to drop coolant temperatures down to 228°F by turning off the air conditioning, despite it being extremely uncomfortable, but having a performance torque converter that generates heat wasn't the most helpful in this situation. Like everyone else, I pulled to the side of the road, popped the hood and let it idle for about 45 minutes before the coolant temperature dropped to 200°F and TFT to 190°F. It didn't matter what you were driving, the side of the freeway was flooded - anything from a Toyota Corolla to a Honda Accord, Toyota Land Cruiser, Nissan Patrol (Armada), Cadillac Escalade, Porsche Cayenne and even a Bentley Continental was parked.

Being where I am, the issue is no longer coolant temperatures at highway speeds but keeping everything cool in congested traffic. People here do all sorts from upgrading fans to installing additional fans. SPAL makes a killing here, but people still complain about nothing working effectively. This is another reason why a high end synthetic with a low NOACK is so important.

 

[PWMDMD]

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.

Maybe...it's just hard to believe a company like Toyota would make such an amateurish mistake in what is their flagship engine being used in some of their most expensive flagship vehicles. Also, again, why not the GX or the LS? Maybe they figured it out before the GX ramped up and I know LS has a slightly different version of the 3.4 but I just have lots of questions and I'm interested to see how this plays out.

 

[BMWTurboDzl]

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)?

All else being equal higher humidity will transfer heat faster because the air is a little denser. ICE cooling systems don't operate off evaporative cooling if that's what you were getting at.

 

[PWMDMD]

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)?

All I know is I have engine and transmission temps displayed on my radio often, and dependent on load and speed in the dead of winter, coolant is between 195-205F. In the dead of summer, the coolant temp is between 195-205F. When it's 100% humidity, the coolant temp is between 195-205F and when it's dry as a bone, it's between 195F and 205F.

The only effect temp seems to have is how quickly the engine gets to temp but it has no noticeable effect on the final temp - that is dependent on engine load and RPM. Humidity has no noticeable effect either.

 

[kschachn]

And I’m guessing the TUNERS are the ones saying ‘it lights off the cats’ so that’s what everyone believes. Same people that say you don’t have to wait for the glow plug light to go off to start a diesel, or you don’t have to let diesels cool down after being driven. It’s people that don’t know or have been told wrong. I see it all the time especially with the CP4 pumps that have a bad rap from people that don’t have a clue

That's certainly definitive.

 

[burbguy82]

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.

Do you not understand that he was NOT just talking about the engine oil, or are you just omitting that fact conveniently, just to be difficult.

Technical terms huh? It is not that complicated. Heat is made by work performed. Simple. To easy for someone of your intellect to understand I suppose. So take a break, eat some Grey Poupon, and have a little respect.

using the engine below

Or course this "partial" sentence assumes that there is a sealed system, which there is NONE.......

 

[frankbee3]

All I know is I have engine and transmission temps displayed on my radio often, and dependent on load and speed in the dead of winter, coolant is between 195-205F. In the dead of summer, the coolant temp is between 195-205F. When it's 100% humidity, the coolant temp is between 195-205F and when it's dry as a bone, it's between 195F and 205F.

The only effect temp seems to have is how quickly the engine gets to temp but it has no noticeable effect on the final temp - that is dependent on engine load and RPM. Humidity has no noticeable effect either.

It sounds to me like your Tundra has a properly designed cooling system that is working correctly. I am wondering if your truck would step out of the 195-205 degree range driving through Death Valley on a 120*F day, or at high density altitude on a lot Colorado day? That would be an interesting thing to observe for sure.

 

[kschachn]

Do you not understand that he was NOT just talking about the engine oil, or are you just omitting that fact conveniently, just to be difficult.

Technical terms huh? It is not that complicated. Heat is made by work performed. Simple. To easy for someone of your intellect to understand I suppose. So take a break, eat some Grey Poupon, and have a little respect.

View attachment 229380
using the engine below
View attachment 229381


View attachment 229388

Or course this "partial" sentence assumes that there is a sealed system, which there is NONE.......

Who wasn't? The whole thread was about that topic with side elements, but one of the illustrations was exactly that subject. Did you miss that?

And you are obviously capable of Internet cut-and-paste, but as was the case with other topics I'm not sure about comprehension.

 

[edyvw]

Air flow is one of the most important factors when it comes to the cooling system. I have experimented with different coolant concentrations in extreme ambient temperatures (120°F - 132°F) over the last couple of weeks, to include going as low as 20% coolant to 80% distilled water. While not the most accurate means of measurement, I have used OBD-II readings to measure both coolant and cylinder head temperatures and the difference I have noticed between a 50/50 ratio to a 20/80 ratio was about an 8°F drop depending on ambient temperature.

With that being said, even with a 20/80 ratio, being stuck in congested traffic is the single worst thing that can happen due to restricted cooler air flow. On Friday, I was driving along a freeway at 70 MPH with a coolant temperature of 222°F and a transmission fluid temperature of 188°F before the entire freeway came to a crawling halt for over 90 minutes due to a crash. This vehicle is equipped with a custom, all-aluminum radiator with increased capacity. With an ambient temperature of 127°F, it didn't take long for the temperatures to start creeping up with other heat sources (vehicles) around. In about 20 minutes, my coolant temperature went up to 236°F and TFT went up to 248°F. I was able to drop coolant temperatures down to 228°F by turning off the air conditioning, despite it being extremely uncomfortable, but having a performance torque converter that generates heat wasn't the most helpful in this situation. Like everyone else, I pulled to the side of the road, popped the hood and let it idle for about 45 minutes before the coolant temperature dropped to 200°F and TFT to 190°F. It didn't matter what you were driving, the side of the freeway was flooded - anything from a Toyota Corolla to a Honda Accord, Toyota Land Cruiser, Nissan Patrol (Armada), Cadillac Escalade, Porsche Cayenne and even a Bentley Continental was parked.

Being where I am, the issue is no longer coolant temperatures at highway speeds but keeping everything cool in congested traffic. People here do all sorts from upgrading fans to installing additional fans. SPAL makes a killing here, but people still complain about nothing working effectively. This is another reason why a high end synthetic with a low NOACK is so important.

You supposed to turn on heating to cool it off

 

[TomYoung]

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."

You asserted something was in most if not all user manuals. Your statement was last true in, maybe, 1980.

 

[OilUzer]

You asserted something was in most if not all user manuals. Your statement was last true in, maybe, 1980.

Again, you are talking CAFE and US.

Please READ the other threads regarding similar subjects. I'm sure there are many!

Someone just recently posted about their brand new 2024 truck from Texas requiring 0W-20 and the pic of the user's manual for the same truck from Mexico having viscosity recommendations based on temperatures!

Last I checked, Mexico ain't far from Texas!

 

[kschachn]

Again, you are talking CAFE and US.

Please READ the other threads regarding similar subjects. I'm sure there are many!

Someone just recently posted about their brand new 2024 truck from Texas requiring 0W-20 and the pic of the user's manual for the same truck from Mexico having viscosity recommendations based on temperatures!

Last I checked, Mexico ain't far from Texas!

What does CAFE (actually EPA) have to do with the winter rating, other than a requirement to recommend only the grade that was tested? Some 0W rated oils are actually thicker than an equivalent 5W rated one, except at extremely low temperatures. I don't think the winter rating has much of a relationship to fuel economy since the differences are not seen at most starting temperatures nor at operation.

 

[svenson]

do we need an oil thicker or shear stable? if the latter then as many here claim 5 is more shear stable.

 

[TomYoung]

Again, you are talking CAFE and US.

Please READ the other threads regarding similar subjects. I'm sure there are many!

Someone just recently posted about their brand new 2024 truck from Texas requiring 0W-20 and the pic of the user's manual for the same truck from Mexico having viscosity recommendations based on temperatures!

Last I checked, Mexico ain't far from Texas!

The only point I was making here is that you are making a downright incorrect assertion about owners manual calling for a winter oil and a different summer oil. Your original post asked the (fair) question, and I paraphrase, that if it is very, very hot outside, should that inform my choice of oil. Generally speaking, a car in proper operating condition will maintain a constant engine temperature without much impact from the ambient temperature. This makes sense, when you think about how thermostats operate in the car’s cooling system. I suppose that if a car cannot stay at an acceptably low operating temperature, the car should be turned off. That said, modern cars are tested in the arctic and in Death Valley and like places around the world. As is so often the case, if you do what the owners manual says, you’ll be fine. There are many folks on BITOG who advocate thicker oils, pointing out HTHS and MOFT advantages, and with the allegation that CAFE standards force the manufacturers to go thin on the oil at the expense of engine durability. That is an interesting and complex ongoing discussion. Another issue is that oils have an appropriate Winter rating to allow the car to start with rapid lubrication in ver cold temperatures. My strong suggestion is to think less, follow the manual and to read the responses in this thread a little more closely. You might benefit from tighter OCIs.

 

[Random_Kiwi]

Anywhere near the region around Australia is Kiwi-land

We are definitely not the same! Barbarian. (im just kidding, its faux outrage and I dont actually mean you are a barbarian)
Queue the sheep jokes and penal colony jokes.

 

[BLND1]

I just completed a 200+ mile trip in 116 degree weather.

2021 VW Atlas. 2.0T.

Oil temps stayed around 219 in normal driving (209 ish on descents) and raising to a peak of 246 on long uphill stages in the mountains. No coolant temps available but I’ll bet it didn’t move much.

Blasted A/C the whole time. No concerns. (Checked oil, coolant, etc. prior to departure)

Having lived in areas where these temps are normal, having a well maintained vehicle is more important than oil grade.

I’ve done similar trips in my 2011 tacoma v6 and never seen coolant temps rise above 200. I don’t have an oil temp available for that vehicle.

 

[I<3oil]

We are definitely not the same! Barbarian. (im just kidding, its faux outrage and I dont actually mean you are a barbarian)
Queue the sheep jokes and penal colony jokes.

Well slap my aunt and throw another shrimp on da barbie, we have an actual Kiwi here

 

[Chumango]

All else being equal higher humidity will transfer heat faster because the air is a little denser. ICE cooling systems don't operate off evaporative cooling if that's what you were getting at.

Adding water vapor will reduce the density since the molecular weight of water (18.0152) is somewhat less than air (28.951). Water vapor has a higher heat capacity than dry air so that helps, but in any case the difference is not large. Even at 100% relative humidity at 100 F there is only 0.0432 lbs of water per lb of dry air.