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What is your oil pressure?

HoosierTrooper

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Can one of you guys who believe that the incredibly tight clearances, not tolerances, of the 5.7L precludes the use of any grade thicker than 20 please explain how 5W-20 can squeeze through those teeny, tiny little clearances when it is cold and thick? The target kinematic viscosity for an API rated 20 grade is around 8.5 cSt but when it’s cold it is many, many times thicker than that so every time the truck is started after setting for any amount of time, like overnight or while the owner is working, it is pumping oil that is nowhere near being a 20 grade until it reaches full operating temperature.

I’m just trying to understand how a cold, thick 5W-20 can squeeze through all those tiny little clearances but a 5W-30, which has the same winter rating and has passed the same ASTM CCS and MRV cold weather performance sequence tests and is only a couple centistokes thicker at operating temperature, can’t.
 

SD Rebel

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Can one of you guys who believe that the incredibly tight clearances, not tolerances, of the 5.7L precludes the use of any grade thicker than 20 please explain how 5W-20 can squeeze through those teeny, tiny little clearances when it is cold and thick? The target kinematic viscosity for an API rated 20 grade is around 8.5 cSt but when it’s cold it is many, many times thicker than that so every time the truck is started after setting for any amount of time, like overnight or while the owner is working, it is pumping oil that is nowhere near being a 20 grade until it reaches full operating temperature.

I’m just trying to understand how a cold, thick 5W-20 can squeeze through all those tiny little clearances but a 5W-30, which has the same winter rating and has passed the same ASTM CCS and MRV cold weather performance sequence tests and is only a couple centistokes thicker at operating temperature, can’t.

Yes, clearances makes more sense. I'm not sure regarding your question, I'm not an engineer, just mentioning what others have said. But I will note on the last part of your question, I don't think they are saying 5W-30 can't do it, they are saying it doesn't do it as well. It's a thicker oil, with tighter clearances it won't do as well as a thinner one. To what degree? It could be nearly negligible. But that still would prove the argument wrong that it's better to run 5W-30 over 5W-20 wouldn't it?

But if I was to fall more on one side, how can I argue the point of the actual engineers and manufacturers that built these engines and their recommendations? If you think it's purely for mpg rating, that makes sense on recommending them on brand new cars that matter on CAFE numbers. Why would they put out a technical bulletin and make a recommendation change on cars produced years earlier if they didn't have to?
 

HoosierTrooper

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20 grade oils are recommended strictly to help the manufacturer meet the yearly CAFE standards, there’s no other reason because 20 grade oils do not perform “better“ than other grades such as 30 or 40. If that were so then there would be no reason for manufacturers to recommend anything but 0W or 5W-20 oils for everything and that is simply not the case. There are numerous modern engines with the supposed “tight“ clearances that recomend higher grades, FCA/Stellantis has at least two. The 2.0L turbocharged Hurricane engine in my Jeep requires 5W-30 and the owners manual actually specifies that it has to be synthetic, and the SRT engines require 0W-40. Outside FCA/Stellantis there are numerous examples, there’s a reason the Corvette comes from the factory with 0W-40 and not 0W-20 like the Sierra, Silverado pickups. Obviously 0W-20 does not provide adequate minimum oil film thickness (MOFT) to protect these engines so a thicker oil is required.

Obviously 5W-20 will provide adequate protection for the 5.7L engines under most conditions, FCA did extensive testing before switching to 5W-20 to ensure that engines weren’t going to self destruct on it, but I’m still waiting for someone to explain how cold, thick 5W-20 can be circulated through these ”tight” clearances but 5W-30 can’t. And how can 5W-20 be better at fitting through those tiny little passages in an engine starting at -15F in North Dakota than 5W-30 in moderate to warm temperatures that is thinner at startup that the 5W-20 in North Dakota is?

As to the manufacturers back specing the 20 grade recommendations to previous years that may be explained in the excerpt below from the NHTSA sites section on the CAFE rules, the Carry back rule states that credits can be applied for three previous model years, that may explain it, but I don’t know for sure.


CAFE Overview​

NHTSA’s CAFE program requires manufacturers of passenger cars and light trucks, produced for sale in the U.S., to meet CAFE standards, expressed in miles per gallon (mpg). The purpose of the CAFE program is to reduce the nation’s energy consumption by increasing the fuel economy of cars and light trucks. Fuel economy standards improve our nation’s energy security, address climate change and save consumers money at the pump. NHTSA establishes separate passenger car (including domestic and import passenger cars) and light truck fleet standards at “the maximum feasible average fuel economy level that it decides the manufacturers can achieve in each model year.” See the United States Code provisions governing the CAFE program. Manufacturers’ compliance obligations are based on the vehicles that are produced for sale in the U.S. in a model year within each of the three fleets: domestic passenger cars (DP), import passenger cars (IP) and light trucks (LT).
Once a manufacturer’s CAFE standard is calculated for each of its fleets, NHTSA compares each of the fleet’s actual mpg performance against the applicable standard. If a manufacturer’s actual average mpg level for a given fleet exceeds the applicable standard, then the manufacturer earns “credits.” A credit is earned for each 1/10 of an mpg in excess of the fleet’s standard mpg and the actual average mpg. Total credits are calculated as the number of tenths of an mpg (1/10 mpg) times the number of vehicles produced for that fleet. On the other hand, if a manufacturer’s actual average mpg level for a given fleet does not meet the applicable standard, then the manufacturer has a “shortfall” for that fleet. Shortfalls can be satisfied by using one of the following compliance flexibilities:
  • Carry forward - credits earned in a particular model year can be carried forward and applied for up to five model years after the year in which the credits were earned.
  • Carry back – credits earned in a particular model year can be carried backward and applied for up to three model years before the year in which the credits were earned.
  • Civil penalty – manufacturers can pay a civil penalty equal to $5.50 per credit shortfall
  • Trade – manufacturers can acquire credits from other manufacturers or credit holders.
  • Transfer – manufacturers can transfer credits from one of their fleets (DP, IP, or LT) to one of their other fleets
 

SD Rebel

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20 grade oils are recommended strictly to help the manufacturer meet the yearly CAFE standards, there’s no other reason because 20 grade oils do not perform “better“ than other grades such as 30 or 40. If that were so then there would be no reason for manufacturers to recommend anything but 0W or 5W-20 oils for everything and that is simply not the case. There are numerous modern engines with the supposed “tight“ clearances that recomend higher grades, FCA/Stellantis has at least two. The 2.0L turbocharged Hurricane engine in my Jeep requires 5W-30 and the owners manual actually specifies that it has to be synthetic, and the SRT engines require 0W-40. Outside FCA/Stellantis there are numerous examples, there’s a reason the Corvette comes from the factory with 0W-40 and not 0W-20 like the Sierra, Silverado pickups. Obviously 0W-20 does not provide adequate minimum oil film thickness (MOFT) to protect these engines so a thicker oil is required.

Obviously 5W-20 will provide adequate protection for the 5.7L engines under most conditions, FCA did extensive testing before switching to 5W-20 to ensure that engines weren’t going to self destruct on it, but I’m still waiting for someone to explain how cold, thick 5W-20 can be circulated through these ”tight” clearances but 5W-30 can’t. And how can 5W-20 be better at fitting through those tiny little passages in an engine starting at -15F in North Dakota than 5W-30 in moderate to warm temperatures that is thinner at startup that the 5W-20 in North Dakota is?

As to the manufacturers back specing the 20 grade recommendations to previous years that may be explained in the excerpt below from the NHTSA sites section on the CAFE rules, the Carry back rule states that credits can be applied for three previous model years, that may explain it, but I don’t know for sure.


CAFE Overview​

NHTSA’s CAFE program requires manufacturers of passenger cars and light trucks, produced for sale in the U.S., to meet CAFE standards, expressed in miles per gallon (mpg). The purpose of the CAFE program is to reduce the nation’s energy consumption by increasing the fuel economy of cars and light trucks. Fuel economy standards improve our nation’s energy security, address climate change and save consumers money at the pump. NHTSA establishes separate passenger car (including domestic and import passenger cars) and light truck fleet standards at “the maximum feasible average fuel economy level that it decides the manufacturers can achieve in each model year.” See the United States Code provisions governing the CAFE program. Manufacturers’ compliance obligations are based on the vehicles that are produced for sale in the U.S. in a model year within each of the three fleets: domestic passenger cars (DP), import passenger cars (IP) and light trucks (LT).
Once a manufacturer’s CAFE standard is calculated for each of its fleets, NHTSA compares each of the fleet’s actual mpg performance against the applicable standard. If a manufacturer’s actual average mpg level for a given fleet exceeds the applicable standard, then the manufacturer earns “credits.” A credit is earned for each 1/10 of an mpg in excess of the fleet’s standard mpg and the actual average mpg. Total credits are calculated as the number of tenths of an mpg (1/10 mpg) times the number of vehicles produced for that fleet. On the other hand, if a manufacturer’s actual average mpg level for a given fleet does not meet the applicable standard, then the manufacturer has a “shortfall” for that fleet. Shortfalls can be satisfied by using one of the following compliance flexibilities:
  • Carry forward - credits earned in a particular model year can be carried forward and applied for up to five model years after the year in which the credits were earned.
  • Carry back – credits earned in a particular model year can be carried backward and applied for up to three model years before the year in which the credits were earned.
  • Civil penalty – manufacturers can pay a civil penalty equal to $5.50 per credit shortfall
  • Trade – manufacturers can acquire credits from other manufacturers or credit holders.
  • Transfer – manufacturers can transfer credits from one of their fleets (DP, IP, or LT) to one of their other fleets

Very good points! You're starting to move my needle over to the other side, but I still don't honestly know the right answer.

What difference of lifespan could we expect with either grades? If there is a tangible difference, is it enough to justify the risk to your factory warranty should there be an issue down the line? Will the dealership use it as an excuse to avoid warranty work like a roller issue? That personally is why I wouldn't use 5W-30, especially since I do my own oil changes and keep a record of my receipts which shows the oil weight I'm using.

I don't want my dealership, who is likely not happy I'm not using them for regular service, to use it as an excuse to screw me over later. That's also why I use the factory oil filter, I don't want to give them any ammo should something happen in the future.

Yes, there is the Magnuson-Moss Act, but I've seen them drag out a legit warranty repair for months regardless, in some cases small claims court before they decided to act. 5W-30, if a positive difference, likely not enough for me to not to follow manufacturer recommendations/requirements, at least while under the 5yr/60k powertrain warranty period.
 
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Neurobit

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Very good points! You're starting to move my needle over to the other side, but I still don't honestly know the right answer.

What difference of lifespan could we expect with either grades? If there is a tangible difference, is it enough to justify the risk to your factory warranty should there be an issue down the line? Will the dealership use it as an excuse to avoid warranty work like a roller issue? That personally is why I wouldn't use 5W-30, especially since I do my own oil changes and keep a record of my receipts which shows the oil weight I'm using.

I don't want my dealership, who is likely not happy I'm not using them for regular service, to use it as an excuse to screw me over later. That's also why I use the factory oil filter, I don't want to give them any ammo should something happen in the future.

Yes, there is the Magnuson-Moss Act, but I've seen them drag out a legit warranty repair for months regardless, in some cases small claims court before they decided to act. 5W-30, if a positive difference, likely not enough for me to not follow manufacturer recommendations/requirements.
Agree fully. Not worth it.
 

HoosierTrooper

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Very good points! You're starting to move my needle over to the other side, but I still don't honestly know the right answer.

What difference of lifespan could we expect with either grades? If there is a tangible difference, is it enough to justify the risk to your factory warranty should there be an issue down the line? Will the dealership use it as an excuse to avoid warranty work like a roller issue? That personally is why I wouldn't use 5W-30, especially since I do my own oil changes and keep a record of my receipts which shows the oil weight I'm using.

I don't want my dealership, who is likely not happy I'm not using them for regular service, to use it as an excuse to screw me over later. That's also why I use the factory oil filter, I don't want to give them any ammo should something happen in the future.

Yes, there is the Magnuson-Moss Act, but I've seen them drag out a legit warranty repair for months regardless, in some cases small claims court before they decided to act. 5W-30, if a positive difference, likely not enough for me to not to follow manufacturer recommendations/requirements, at least while under the 5yr/60k powertrain warranty period.
I'm not trying to convince anyone it's OK to use any oil grade other than the recommended, not required, 5W-20 in their trucks. Member stevj posted some concerns about his oil temp while towing back in January and stated that he uses 5W-30 and 5W-40, the thread was recently resurrected which brought about the usual responses about the tight "tolerances" and the engine being designed to only run on 5W-20 and that anything else is too thick. I'm simply asking for someone to explain to me how cold, thick 5W-20 can find its way into all those little nooks and crannies but 5W-30 can't.

20 grade oils are on the minimum side when it comes to providing adequate MOFT and HTHS viscosity so if the 20 grade is seeing higher than normal temps and higher than normal RPM's for extended times while towing then there is a chance that the already thin MOFT can be compromised and metal to metal contact could occur. Using a higher grade of oil that will provide a slightly higher MOFT and HTHS viscosity can provide a little bit of insurance against that. It's up to each owner to make an informed decision if he or she wants to go outside the recommended 5W-20. Anecdotally, there are plenty of owners of 5.7L engines, not just 1500's but Chargers, Jeeps etc using higher grades without issue. Our own member @silver billet has reported successfully using Redline 5W-30 which is blended on the upper end of the 30 grade range without issue, and on another Ram forum Redline 5W-30 has a very dedicated following.

The owners manual is rather vague. Nowhere does it state that using any grade other than the recommended 5W-20 will void your warranty, at least I've not been able to find that verbiage in mine. It does recommend using an oil that meets MS-6395 and displays the API certification label, which most 5W-30 oils produced by the majors meet. Would FCA/Stellantis have a problem with someone using a 5W-30 that meets their own material standard and is licensed by the API like they recommend? Beats me.
 

SD Rebel

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I'm not trying to convince anyone it's OK to use any oil grade other than the recommended, not required, 5W-20 in their trucks. Member stevj posted some concerns about his oil temp while towing back in January and stated that he uses 5W-30 and 5W-40, the thread was recently resurrected which brought about the usual responses about the tight "tolerances" and the engine being designed to only run on 5W-20 and that anything else is too thick. I'm simply asking for someone to explain to me how cold, thick 5W-20 can find its way into all those little nooks and crannies but 5W-30 can't.

20 grade oils are on the minimum side when it comes to providing adequate MOFT and HTHS viscosity so if the 20 grade is seeing higher than normal temps and higher than normal RPM's for extended times while towing then there is a chance that the already thin MOFT can be compromised and metal to metal contact could occur. Using a higher grade of oil that will provide a slightly higher MOFT and HTHS viscosity can provide a little bit of insurance against that. It's up to each owner to make an informed decision if he or she wants to go outside the recommended 5W-20. Anecdotally, there are plenty of owners of 5.7L engines, not just 1500's but Chargers, Jeeps etc using higher grades without issue. Our own member @silver billet has reported successfully using Redline 5W-30 which is blended on the upper end of the 30 grade range without issue, and on another Ram forum Redline 5W-30 has a very dedicated following.

The owners manual is rather vague. Nowhere does it state that using any grade other than the recommended 5W-20 will void your warranty, at least I've not been able to find that verbiage in mine. It does recommend using an oil that meets MS-6395 and displays the API certification label, which most 5W-30 oils produced by the majors meet. Would FCA/Stellantis have a problem with someone using a 5W-30 that meets their own material standard and is licensed by the API like they recommend? Beats me.

Absolutely, I'm not working under the assumption you are, I'm also curious about this stuff, but just mentioning why I wouldn't use it right now. Maybe later, after my warranty period is over.

Yeah, the manual is rather vague, vague enough for them to stab me in the back if it suits them should I ever need to actually use my warranty. I know at least, there is 100% no chance they can get me for my oil or filter with my DIY changes, with FCA approved oils at their recommended weights and Mopar filter
 

HoosierTrooper

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Absolutely, I'm not working under the assumption you are, I'm also curious about this stuff, but just mentioning why I wouldn't use it right now. Maybe later, after my warranty period is over.

Yeah, the manual is rather vague, vague enough for them to stab me in the back if it suits them should I ever need to actually use my warranty. I know at least, there is 100% no chance they can get me for my oil or filter with my DIY changes, with FCA approved oils at their recommended weights and Mopar filter
Understand completely. I gotta admit it would be fun to watch them argue that using a 5W-30 that passed all of the testing required to meet MS-6395 including the Las Vegas fleet test and received the certification was responsible for damaging one of their engines.
 

SD Rebel

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Understand completely. I gotta admit it would be fun to watch them argue that using a 5W-30 that passed all of the testing required to meet MS-6395 including the Las Vegas fleet test and received the certification was responsible for damaging one of their engines.

That would be cool, and it would open up a huge can of worms regarding this stuff. But I'm sure they can make something up : )
 

Snekpete

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20 grade oils are recommended strictly to help the manufacturer meet the yearly CAFE standards, there’s no other reason because 20 grade oils do not perform “better“ than other grades such as 30 or 40. If that were so then there would be no reason for manufacturers to recommend anything but 0W or 5W-20 oils for everything and that is simply not the case. There are numerous modern engines with the supposed “tight“ clearances that recomend higher grades, FCA/Stellantis has at least two. The 2.0L turbocharged Hurricane engine in my Jeep requires 5W-30 and the owners manual actually specifies that it has to be synthetic, and the SRT engines require 0W-40. Outside FCA/Stellantis there are numerous examples, there’s a reason the Corvette comes from the factory with 0W-40 and not 0W-20 like the Sierra, Silverado pickups. Obviously 0W-20 does not provide adequate minimum oil film thickness (MOFT) to protect these engines so a thicker oil is required.

This is my understanding as well, the thinner oils are strictly to meet CAFE standards and those vary by country. 5W-20 weight oil is 5 weight oil, period. It then contains up to 20% in additives most of which are to keep it from thinning out at operating temperature. 10W-30 weight oil is 10 weight oil, with additives, period. 10 weight oil is plenty thin enough for a Hemi. I remember when we used to run 30, 40, and 50 weight in Hemis.

This article is from the only mechanic that I trust, Mike Busch. Although it is about air cooled Airplane motors, the oil information it contains applies to all oils. I fly a 580 Lycoming, 330 HP, 2800 rpm max. I use straight conventional 40 weight oil for temps below 60 and straight conventional 50 weight oil for temps above 60. The Aeroshell 15W-50 multi-viscosity oil foams up in this motor, it is too thin when hot.

Mike Busch on oil
 

BowDown

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20 grade oils are recommended strictly to help the manufacturer meet the yearly CAFE standards, there’s no other reason because 20 grade oils do not perform “better“ than other grades such as 30 or 40. If that were so then there would be no reason for manufacturers to recommend anything but 0W or 5W-20 oils for everything and that is simply not the case. There are numerous modern engines with the supposed “tight“ clearances that recomend higher grades, FCA/Stellantis has at least two. The 2.0L turbocharged Hurricane engine in my Jeep requires 5W-30 and the owners manual actually specifies that it has to be synthetic, and the SRT engines require 0W-40. Outside FCA/Stellantis there are numerous examples, there’s a reason the Corvette comes from the factory with 0W-40 and not 0W-20 like the Sierra, Silverado pickups. Obviously 0W-20 does not provide adequate minimum oil film thickness (MOFT) to protect these engines so a thicker oil is required.

Obviously 5W-20 will provide adequate protection for the 5.7L engines under most conditions, FCA did extensive testing before switching to 5W-20 to ensure that engines weren’t going to self destruct on it, but I’m still waiting for someone to explain how cold, thick 5W-20 can be circulated through these ”tight” clearances but 5W-30 can’t. And how can 5W-20 be better at fitting through those tiny little passages in an engine starting at -15F in North Dakota than 5W-30 in moderate to warm temperatures that is thinner at startup that the 5W-20 in North Dakota is?

As to the manufacturers back specing the 20 grade recommendations to previous years that may be explained in the excerpt below from the NHTSA sites section on the CAFE rules, the Carry back rule states that credits can be applied for three previous model years, that may explain it, but I don’t know for sure.


CAFE Overview​

NHTSA’s CAFE program requires manufacturers of passenger cars and light trucks, produced for sale in the U.S., to meet CAFE standards, expressed in miles per gallon (mpg). The purpose of the CAFE program is to reduce the nation’s energy consumption by increasing the fuel economy of cars and light trucks. Fuel economy standards improve our nation’s energy security, address climate change and save consumers money at the pump. NHTSA establishes separate passenger car (including domestic and import passenger cars) and light truck fleet standards at “the maximum feasible average fuel economy level that it decides the manufacturers can achieve in each model year.” See the United States Code provisions governing the CAFE program. Manufacturers’ compliance obligations are based on the vehicles that are produced for sale in the U.S. in a model year within each of the three fleets: domestic passenger cars (DP), import passenger cars (IP) and light trucks (LT).
Once a manufacturer’s CAFE standard is calculated for each of its fleets, NHTSA compares each of the fleet’s actual mpg performance against the applicable standard. If a manufacturer’s actual average mpg level for a given fleet exceeds the applicable standard, then the manufacturer earns “credits.” A credit is earned for each 1/10 of an mpg in excess of the fleet’s standard mpg and the actual average mpg. Total credits are calculated as the number of tenths of an mpg (1/10 mpg) times the number of vehicles produced for that fleet. On the other hand, if a manufacturer’s actual average mpg level for a given fleet does not meet the applicable standard, then the manufacturer has a “shortfall” for that fleet. Shortfalls can be satisfied by using one of the following compliance flexibilities:
  • Carry forward - credits earned in a particular model year can be carried forward and applied for up to five model years after the year in which the credits were earned.
  • Carry back – credits earned in a particular model year can be carried backward and applied for up to three model years before the year in which the credits were earned.
  • Civil penalty – manufacturers can pay a civil penalty equal to $5.50 per credit shortfall
  • Trade – manufacturers can acquire credits from other manufacturers or credit holders.
  • Transfer – manufacturers can transfer credits from one of their fleets (DP, IP, or LT) to one of their other fleets


Lunati nor Morel have to be concerned with CAFE standards or emissions and both recommend 5/20 or 5/30 when using their lifters due to the clearances and bleed down rates within the lifter. All these oils are blends so they should all operate the same or similar in cold conditions with the 5w20 obviously being better.
ERL Performance (also not concerned with cafe standards) built the engine for my Z06 strongly recommended 5w20 or 5w30 specifically because of the tight clearances which are only a couple ten thousandth tighter than factory. The HEMI is clearanced just as tight

Capture.JPG
 

BowDown

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20 grade oils are recommended strictly to help the manufacturer meet the yearly CAFE standards, there’s no other reason because 20 grade oils do not perform “better“ than other grades such as 30 or 40. If that were so then there would be no reason for manufacturers to recommend anything but 0W or 5W-20 oils for everything and that is simply not the case. There are numerous modern engines with the supposed “tight“ clearances that recomend higher grades, FCA/Stellantis has at least two. The 2.0L turbocharged Hurricane engine in my Jeep requires 5W-30 and the owners manual actually specifies that it has to be synthetic, and the SRT engines require 0W-40. Outside FCA/Stellantis there are numerous examples, there’s a reason the Corvette comes from the factory with 0W-40 and not 0W-20 like the Sierra, Silverado pickups. Obviously 0W-20 does not provide adequate minimum oil film thickness (MOFT) to protect these engines so a thicker oil is required.

This is my understanding as well, the thinner oils are strictly to meet CAFE standards and those vary by country. 5W-20 weight oil is 5 weight oil, period. It then contains up to 20% in additives most of which are to keep it from thinning out at operating temperature. 10W-30 weight oil is 10 weight oil, with additives, period. 10 weight oil is plenty thin enough for a Hemi. I remember when we used to run 30, 40, and 50 weight in Hemis.

This article is from the only mechanic that I trust, Mike Busch. Although it is about air cooled Airplane motors, the oil information it contains applies to all oils. I fly a 580 Lycoming, 330 HP, 2800 rpm max. I use straight conventional 40 weight oil for temps below 60 and straight conventional 50 weight oil for temps above 60. The Aeroshell 15W-50 multi-viscosity oil foams up in this motor, it is too thin when hot.

Mike Busch on oil

Incorrect
What do the numbers in 5W-20 mean? The numbers refer to the weight and thickness, or viscosity, of the oil. Motor oil gets thicker when it’s cold and thinner when it heats up. The first number indicates the viscosity of the oil at a cold temperature, and the second number indicates the viscosity at operating temperatures. https://www.mobil.com/en/lubricants...roducts/motor-oils/mobil-5w-20-viscosity-oils
Also see:
 

HoosierTrooper

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Lunati nor Morel have to be concerned with CAFE standards or emissions and both recommend 5/20 or 5/30 when using their lifters due to the clearances and bleed down rates within the lifter. All these oils are blends so they should all operate the same or similar in cold conditions with the 5w20 obviously being better.
ERL Performance (also not concerned with cafe standards) built the engine for my Z06 strongly recommended 5w20 or 5w30 specifically because of the tight clearances which are only a couple ten thousandth tighter than factory. The HEMI is clearanced just as tight

View attachment 101030
Their recommendation that you can use either 5W-20 or 5W-30 is in line with the point I’ve been trying to make concerning the 5.7L, that the clearances are not so tight that a 30 grade can’t be used in it, possible warranty concern aside. The 5W-20 recommendation for the 5.7L is purely based on CAFE, the EPA requires that whatever grade of oil is used for the mileage tests has to be the factory fill and what they recommend in the owners manual. In other words FCA can’t use 5W-20 for the mileage tests and then fill them with 5W-30 and list that grade in the owners manual.

Years ago a lot of vehicles listed multiple grades in the owners manual that where authorized, usually based on expected ambient temperatures, but now it’s usually just the one grade that was used for the mileage test. In my not so humble opinion FCA, and Ford and Chevrolet and Toyota should be able to give owners the option to go to a higher grade if they are going to be towing or operating in other severe conditions but their hands are tied so they just recommend the one grade for every operating condition.
 

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Their recommendation that you can use either 5W-20 or 5W-30 is in line with the point I’ve been trying to make concerning the 5.7L, that the clearances are not so tight that a 30 grade can’t be used in it, possible warranty concern aside. The 5W-20 recommendation for the 5.7L is purely based on CAFE, the EPA requires that whatever grade of oil is used for the mileage tests has to be the factory fill and what they recommend in the owners manual. In other words FCA can’t use 5W-20 for the mileage tests and then fill them with 5W-30 and list that grade in the owners manual.

Years ago a lot of vehicles listed multiple grades in the owners manual that where authorized, usually based on expected ambient temperatures, but now it’s usually just the one grade that was used for the mileage test. In my not so humble opinion FCA, and Ford and Chevrolet and Toyota should be able to give owners the option to go to a higher grade if they are going to be towing or operating in other severe conditions but their hands are tied so they just recommend the one grade for every operating condition.

Honestly, I think it more has to do with the lifters, specifically the MDS functionality. I know GM DOD (same as MDS) lifters are extremely sensitive to oil weight, I have no doubt the HEMI lifters are too. I had lengthy conversations with my engine builder regarding clearances and lubrication, they all said the same thing, use the lightest oil you can get away with because of oil control on the bearing surfaces and lifter functionality. Obviously fuel economy wasn't a factor, you build these engines tighter and need a thinner oil, tighter will make the engine live longer especially with big power or power adders. A "loose" bearing clearance allows the crank/rod more movement on each combustion event. Floating the crank on a thin layer of oil yet allowing it little movement reduces your chances of hurting a bearing surface and the lifters bleeding down correctly which is needed due to the extremes cam ramps used today along with various displacement systems.

Cafe standards, IDK, obviously they need every once of help they can get, a .25% here and .33% there starts adding up. I beat the S out of my Z06 running 5w20 and 5w30 and routinely see oil temps in the 240-250° which still isn't hot. The HEMI in my truck will be fine with 5w20, no need for me to reinvent the wheel, that oil will handle anything I throw at it in this truck. I am curious as to what all these HEMI lifter failure people were doing oil and maintenance wise.

I dont think a higher grade is necessary for towing, you'll never get the oil as hot towing as I do on a track day, you'd be better served working on increasing the cooling as synthetic oil can get 500°+ and still provide good protection, at that temp, oil is going to be your concern.

5W20 has a flash point of 453° so you'd be ok
 
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HoosierTrooper

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Honestly, I think it more has to do with the lifters, specifically the MDS functionality. I know GM DOD (same as MDS) lifters are extremely sensitive to oil weight, I have no doubt the HEMI lifters are too. I had lengthy conversations with my engine builder regarding clearances and lubrication, they all said the same thing, use the lightest oil you can get away with because of oil control on the bearing surfaces and lifter functionality. Obviously fuel economy wasn't a factor, you build these engines tighter and need a thinner oil, tighter will make the engine live longer especially with big power or power adders. A "loose" bearing clearance allows the crank/rod more movement on each combustion event. Floating the crank on a thin layer of oil yet allowing it little movement reduces your chances of hurting a bearing surface and the lifters bleeding down correctly which is needed due to the extremes cam ramps used today along with various displacement systems.

Cafe standards, IDK, obviously they need every once of help they can get, a .25% here and .33% there starts adding up. I beat the S out of my Z06 running 5w20 and 5w30 and routinely see oil temps in the 240-250° which still isn't hot. The HEMI in my truck will be fine with 5w20, no need for me to reinvent the wheel, that oil will handle anything I throw at it in this truck. I am curious as to what all these HEMI lifter failure people were doing oil and maintenance wise.

I dont think a higher grade is necessary for towing, you'll never get the oil as hot towing as I do on a track day, you'd be better served working on increasing the cooling as synthetic oil can get 500°+ and still provide good protection, at that temp, oil is going to be your concern.

5W20 has a flash point of 453° so you'd be ok
I agree that one should use the thinnest oil possible, but I consider API certified 30 grade oils to be thin. As I’ve pointed out the difference in KV between most API 20 and 30 grades is only a couple cSt at 212F, and we’re not talking about running 15W-50 or BMW 10W-60 in the 5.7L.

I use Pennzoil Platinum 5W-20 in mine. I will never tow anything with it but if I did I would feel comfortable bumping it up to Platinum 5W-30, which is what I run in my Jeep turbo, knowing that I have a little extra cushion in case I’m pushing the limits of the MOFT and HTHS and that the 5W-30 isn’t going to adversely affect the operation of the engine. I’ve never read the paper by Lubrication Engineers but they made the point that high loads and heat can affect viscosity selection, which can definitely be a factor towing a heavy trailer as opposed to just puttering around town like I do most of the time in mine!

Edited to add that the flash point for Platinum 5W-20 is 401F and it’s my understanding that the flash point number is more for first responders information than a property of the oil.
 
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What do you guys think now that they have moved to 0-20w ? Same engine

Surprised they didn't do it sooner. Almost everything I now own (or take care of) runs on 0W-20, including the wifes 22' Suburban 6.2L right down to my Mom's Toyota C-HR 2.4L.

I'm considering the switch myself since I can use the same oil that works (approved) with GM, Toyota and Chrysler in synthetic.
 

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Surprised they didn't do it sooner. Almost everything I now own (or take care of) runs on 0W-20, including the wifes 22' Suburban 6.2L right down to my Mom's Toyota C-HR 2.4L.

I'm considering the switch myself since I can use the same oil that works (approved) with GM, Toyota and

Surprised they didn't do it sooner. Almost everything I now own (or take care of) runs on 0W-20, including the wifes 22' Suburban 6.2L right down to my Mom's Toyota C-HR 2.4L.

I'm considering the switch myself since I can use the same oil that works (approved) with GM, Toyota and Chrysler in synthetic.
Im wondering how it will perform being i live just outside Phoenix,AZ and i travel up north with lots of mountains and hills towing a load sometimes . My truck will see lots of high temps and long hills
 

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Im wondering how it will perform being i live just outside Phoenix,AZ and i travel up north with lots of mountains and hills towing a load sometimes . My truck will see lots of high temps and long hills

Yup, definitely a concern in those conditions.

But I wonder since the thermostat keeps the engine coolant temps at around 200F - 230F regardless of outside temp, I wonder if the oil is being actually worked harder in those climates?

Towing however can pretty abusive to oil temps.
 

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