Rebels Come Calling ( Who is not running 0W-20 Oil ? )

Pearl2017 · August 24, 2018

I will run M1 15-50 or T6 15-40 in AZ summer heat trailer towing. But also have used the free 0w-5w-20 changes without fear in the mild winter. To even try to understand why someone would run heavier oil you must first understand how the oil works between the moving parts. Put as simply as possible the pressurized oil provides a fluid bearing between the rotating parts ...we all know this for sure. But as you make lots of power or pull heavy loads the mechanical stress that is trying to CRUSH the fluid bearings is substantial and creates a LOT of HEAT ...if that's not bad enough they also now purposely run the engines coolant much hotter. ...of course also not for longer engine life. So in this really hot oil crushing environment if the 20w oil starts to lose a little of its viscosity you just don't have as much safety margin as a 30w-50w does. ...For some reason the 0w crowd wants to keep trying to convince everyone else what a great idea it is.

Kubs · August 24, 2018

I run AMSOIL Signature Series 5W-30 in my 5.3L '18. I actually picked up 10psi hot oil pressure at idle. Cold pressures are still good, not too high and I didnt lose any MPG. I also use an AMSOIL Absolute Efficiency oil filter (EAO17).

Denali_King · August 24, 2018

1 hour ago, Kubs said:

I run AMSOIL Signature Series 5W-30 in my 5.3L '18. I actually picked up 10psi hot oil pressure at idle. Cold pressures are still good, not too high and I didnt lose any MPG. I also use an AMSOIL Absolute Efficiency oil filter (EAO17).

That's what I run. Didn't see any difference in oil pressure or mileage.

seamus2154 · August 24, 2018

9 hours ago, Pearl2017 said:

I will run M1 15-50 or T6 15-40 in AZ summer heat trailer towing. But also have used the free 0w-5w-20 changes without fear in the mild winter. To even try to understand why someone would run heavier oil you must first understand how the oil works between the moving parts. Put as simply as possible the pressurized oil provides a fluid bearing between the rotating parts ...we all know this for sure. But as you make lots of power or pull heavy loads the mechanical stress that is trying to CRUSH the fluid bearings is substantial and creates a LOT of HEAT ...if that's not bad enough they also now purposely run the engines coolant much hotter. ...of course also not for longer engine life. So in this really hot oil crushing environment if the 20w oil starts to lose a little of its viscosity you just don't have as much safety margin as a 30w-50w does. ...For some reason the 0w crowd wants to keep trying to convince everyone else what a great idea it is.

This is the part most guys don't get. Ow is designed for just cold start up and it is great at it. But a lighter weight oil can't perform as well under heat and load. Some guys believe the thermostat regulates their oil temp and performance which is completly untrue. A heavier oil does take longer to get up to temp, but performs better when working and under load. And keeps a lower temp. But most people are spoiled with fuel injection and just start up and go. Which GM knows. That can hurt your engine as the oil is not flowing and protecting well cold. Gm doesnt want to warranty that damage. So a 0w oil kinda idiot proofs things and lowers GM's warrantys as people do not take an interest in understanding their engine. They also do not warm up their engine. So 0w is GM insurance.

I ran 5/30 in my corvette at the track as recommended. My engine was ticking like crazy and my oil temps were 285 degrees! Track guys educated me and I started running 15/50 Mobil 1. Oil pressure is very high at start up and MUST be warmed up properly....but on the track I hold good oil pressure (protection) and my temps are a max of 250 degrees. BIG difference. But I understand that the oil is not working well till it hits 160 degrees and not to rev it up. Most start and go.

If your towing, working it , and its Africa hot out a higher viscosity is needed. But that doesn't apply to northern winters where a high viscosity oil can do more damage on a cold start up.

Sierra Dan · August 24, 2018

So based on what I have read so far, 5w-30 would be an overall ideal viscosity for every day driving in the Midwest with our trucks?

How many of you are running this combo?

Kubs · August 24, 2018

3 hours ago, Denali_King said:

That's what I run. Didn't see any difference in oil pressure or mileage.

I always pay close attention to my gauges. HOT pressure at IDLE went from 20psi to 30psi. Normal operating pressure and cold pressure remain the same.

Grumpy Bear · August 24, 2018

3 hours ago, seamus2154 said:

This is the part most guys don't get. Ow is designed for just cold start up and it is great at it. But a lighter weight oil can't perform as well under heat and load. Some guys believe the thermostat regulates their oil temp and performance which is completly untrue. A heavier oil does take longer to get up to temp, but performs better when working and under load. And keeps a lower temp. But most people are spoiled with fuel injection and just start up and go. Which GM knows. That can hurt your engine as the oil is not flowing and protecting well cold. Gm doesnt want to warranty that damage. So a 0w oil kinda idiot proofs things and lowers GM's warrantys as people do not take an interest in understanding their engine. They also do not warm up their engine. So 0w is GM insurance.

I ran 5/30 in my corvette at the track as recommended. My engine was ticking like crazy and my oil temps were 285 degrees! Track guys educated me and I started running 15/50 Mobil 1. Oil pressure is very high at start up and MUST be warmed up properly....but on the track I hold good oil pressure (protection) and my temps are a max of 250 degrees. BIG difference. But I understand that the oil is not working well till it hits 160 degrees and not to rev it up. Most start and go.

If your towing, working it , and its Africa hot out a higher viscosity is needed. But that doesn't apply to northern winters where a high viscosity oil can do more damage on a cold start up.

Completely? My 262's oil cooler is in the hot side tank of my radiator. Piston jets for cooling. Lower block temp, lower oil temp by a bunch. Measured not guessed at.

Curious. Oil temp is in the nose bleed seats and you choose to cook a more viscous oil rather than cool the less viscous oil back to a sane viscosity level. Why that method?

Denali_King · August 24, 2018

14 minutes ago, Kubs said:

I always pay close attention to my gauges. HOT pressure at IDLE went from 20psi to 30psi. Normal operating pressure and cold pressure remain the same.

I have a Denali and like this gauge setup best. You have to be in towhaul to see oil pressure and trans temp.

seamus2154 · August 24, 2018

2 hours ago, Grumpy Bear said:

Completely? My 262's oil cooler is in the hot side tank of my radiator. Piston jets for cooling. Lower block temp, lower oil temp by a bunch. Measured not guessed at.

Curious. Oil temp is in the nose bleed seats and you choose to cook a more viscous oil rather than cool the less viscous oil back to a sane viscosity level. Why that method?

https://mobiloil.com/en/motor-oils/mobil-1/mobil-1?WT.mc_id=700000001351664_71700000014297254_58700001193111920_p10530097599&WT.srch=1

https://www.mobil.com/English-US/Passenger-Vehicle-Lube/pds/GLXXMobil-1-0W20

Once hot, the shear strength, viscosity at temp, really come into play for protection under load. Of all their oils and viscosities 0w20 is one of the lowest, but it is one of the best for cold start and pour rate, which does effect most of you wear at start. I would say it's middle of the raod covering the whole country. But Arizona, Texas, and Florida have a different problem.

Tracking a Zo6 is probably not the best comparision to us towing and the protection from the oil in our trucks. Looking at your temp gauge is all most people do and figure that is how hot their oil is. Not true. People would be surprised if they stared at the oil temp gauge while driving and realize it takes alot of time getting up to temp. That is the problem with a heavier oil. It can also exceed the coolant temperature when your working it. Most guys with sports cars and higher viscosity oil know not to rev till at least 160 degrees. My BMW m3 actually has a redline that moves as the oil it gets warmer. They only recommend one viscosity no matter the temp. 10w60, which is crazy thick at colder temps.

To answer your question when tracking, there are plenty of parts of the track where you are at a lower speed but reving at 7000 rpm's.....creating alot of heat in the oil. Then you get to a faster straight and it's just not enough time and air to cool it down. Because oil holds heat and is harder to cool. Do this for an hour and you can get some big oil temp numbers. The corvette is limited to only so much front area for taking in air and it cools the power steering, differential, trans, coolant,.....and oil. I have alot of modifications to track but dont want to make my car less steetable w/ bigger setrab coolers and fans. So the 15w50 does not get as hot, holds good oil pressure at temp, and my wear metals in my oil analysis are much lower indicating its holding up better under that use. So once hot I can't get the temp down easily except to get off the track and drive normal! (Thats no fun) Now higher viscosity in some climates can be detrimental and take way too long to get to their optimal operating temperature. So with my limited coolers and air flow the 15w50 works best even though I am beating it up. It's a one day oil anyway.

Nascar can dial in their oil temp alot better than I can because they are at a pretty constant speed and rpm, know outside air temp, and actual restrict airflow if the oil is too cool which is as bad as too hot. .

0w20 is probably best for most guys. But I think the specs speak for themselves when hot and under load in the south.

iPhonez71 · August 24, 2018

Couple decades ago, I used motor oil to treat a power steering rack and pinion from a 89 Corolla that few bottles of anti-leak power steering treatment fluid could not stopped. Motor oil worked really well about 3.5 years until I donated (not worth fixing) because it cost too much to replace engine gasket from a coolant leak and did not pass smog. Anyhow, I think manufacturers don’t have enough new owners data to pre-recommend to other new owners . At best, they recommend based on an average historical data tested from various laboratories. Each of us operates and maintains differently. We represent data and be more useful data, but no one is collecting. We know our vehicles more than anyone else. It depends on climate regions of one lives and their driving and oil changing habits. 0w-20 synthetic oil may not be an optimum choice or necessary if changing oil more often than GM recommended. I found various information on this forum can be very useful data for motor industries especially for GM. Some one on here needs to compile the data.

loganck97 · August 24, 2018

so, living in Phoenix/ san Diego and occasionally towing a boat throughout the year would 5W-30 be the most recommended or even heavier in the AZ heat? Thanks for starting this thread, I'm learning a lot I had no idea about.

Sierra Dan · August 24, 2018

I figured I was not the only one questioning the oil weight, and that there were others out there like me wanting to switch from 0w-20

loganck97 · August 24, 2018

2 minutes ago, Sierra Dan said:

I figured I was not the only one questioning the oil weight, and that there were others out there like me wanting to switch from 0w-20

truthfully I never would have though about it based on GM's recommendations, but it makes sense to want a heavier oil if it will never be very cold during start up and with the AZ heat

seamus2154 · August 24, 2018

7 hours ago, Sierra Dan said:

So based on what I have read so far, 5w-30 would be an overall ideal viscosity for every day driving in the Midwest with our trucks?

How many of you are running this combo?

Absolutely. Look at the pour rate and cold viscosity on their website. Its just a small bit better but still good for cold temps. It's in the Camaro and Corvette.

Grumpy Bear · August 24, 2018

2 hours ago, seamus2154 said:

Once hot, the shear strength, viscosity at temp, really come into play for protection under load. Of all their oils and viscosities 0w20 is one of the lowest, but it is one of the best for cold start and pour rate, which does effect most of you wear at start. I would say it's middle of the raod covering the whole country. But Arizona, Texas, and Florida have a different problem.

Given your special conditions on track day it makes sense if you can't get the air or cooler space to cool it. I understand. Thanks. Reference is everything, is it not?

Here's another; 500 CID 1500 HP Pro Stock motors use.....straight 0 or 5 weight. Shear strength is tied hard to base oil chemistry and viscosity. Not the viscosity in the bottle but 'under operating conditions". 15W50 at 250F is no more viscous than 0W20 at 200 F. They count on it give the short run times of an NHRA Pro Stock motor. They are tied at the hip. Temp/viscosity/shear strength/chemistry.

Just offering a link I like on the topic. Love the paragraphs on Mineral vs Synthetic chemical structures. Anyway, someone might find it useful...or not.

http://www.kewengineering.co.uk/Auto_oils/oil_viscosity_explained.htm

Edited August 24, 2018 by Grumpy Bear