What 5W-30 oil brand are you using for the 6.6L gas?

[Chuck FB]

2 hours ago, KARNUT said:

There’s a lot made about oil and filters. Working with my family business I’ve owned many vehicles and equipment. It’s in the hundreds. Two hundred myself. We’ve even had a salvage yard for awhile. My father thought it would be a good idea. Most vehicles we bought off the public were driven in. Couldn’t pass emissions and too costly to get them to pass. Iv had two failures in my lifetime. One drag racing. Spun a bearing still drove home. A Ram V-10 pulling a tractor cross country a factory defect replaced at the dealership for free. Usually the culprit is something other than oil for engine problems. It seems valvoline may have an answer with build up problems with restore and protect. It’s entertaining reading about people worrying about oil and filters. 

While it is true a lot is talked about with oils and filters, in terms of diesel engines for example the introduction of the EGR was one that is capable of loading the oil up with far more soot than ever before and new formulations of oil came out at the time to deal with that and they also designed some spin on filters with a portion of it as a finer bypass filter to attempt to filter out some of the soot. In my mind forced to come up with solutions to keep the engine alive within an expected life cycle while running with an oil that has a fine grinding compound being pumped into it and it does show up in bore polishing from what I understand. And of course we are still dealing with that issue today forcing an engine to swallow something harmful to itself, then pushing thinner oils to boot onto it. But neither issue is really an oils fault, its being made to do a job with those at the top pulling the strings to force compliance to add what amounts to engine added wear, by contamination of oil and by too thin an oil forced into operating at too high a temperature. 

 

I have had a couple of engines fail on me, well should say the one was my dads as that is long ago and nothing to do with the oil in that case as it was a cracked head on a low mileage vehicle dad had bought new. The other was a pickup I still have but with a factory new long block I put in after the original engine with quite a few miles on it suddenly started to knock and there is a back story to that and guesses as to what lead up to the engine wiping out a connecting rod bearing and yes I drove it home carefully as the piston was kissing the head as I had nothing to loose ... a challenge, can I limp it home or do I have to call a tow truck LOL. The bigger worry about engines on the farm is if something in the air cleaner ducting fails and the engine ingests field dust, or an injector fails and would damage a cylinder. Oil related would be trying to turn over an engine in too cold a temperature with the wrong grade of oil, not the oils fault but the fault of using an oil in a condition it was not designed to operate in unless it was artificially warmed up by block heater and pan heater before it was started as I have certainly heard of turning crank or rod bearings by turning over a cold engine. That was why I switched over to 0W-40 for all my diesels that might be expected to be used during the winter while running 15W-40 in all other diesels that never get used during the winter. Knock on wood I never had a bearing turn while starting during the winter. Just another issue that Texas would not have to deal with thankfully and wish I didn't either.  

 

A friend of mine used to have a salvage yard, in fact a vehicle salvage yard and a scrap steel yard ( two separate entities ) but where his vehicles often came from were ones that some shop worked on and the owner could not pay the bill so the vehicle sat there and would be a total loss to the mechanics shop, the other were all the broken down vehicles sitting in peoples yards in town and the city ordinance forcing the owner to get it out of there and so my friend also had tow trucks for his vehicle salvage business and would pick up said vehicles either for nothing or get paid a bit and then keep the vehicle for salvage. It sure can be a scum bag underworld though dealing in salvage and some of the people that would come for parts and the real winners my friend would hire as that was all on him, that's a whole other story LOL. Of course here one is dealing with rust on older vehicles so its not like its a nice looking vehicle with a mechanical issue unless one is dealing in newer iron on wheels.  

[KARNUT]

4 minutes ago, Chuck FB said:

While it is true a lot is talked about with oils and filters, in terms of diesel engines for example the introduction of the EGR was one that is capable of loading the oil up with far more soot than ever before and new formulations of oil came out at the time to deal with that and they also designed some spin on filters with a portion of it as a finer bypass filter to attempt to filter out some of the soot. In my mind forced to come up with solutions to keep the engine alive within an expected life cycle while running with an oil that has a fine grinding compound being pumped into it and it does show up in bore polishing from what I understand. And of course we are still dealing with that issue today forcing an engine to swallow something harmful to itself, then pushing thinner oils to boot onto it. But neither issue is really an oils fault, its being made to do a job with those at the top pulling the strings to force compliance to add what amounts to engine added wear, by contamination of oil and by too thin an oil forced into operating at too high a temperature. 

 

I have had a couple of engines fail on me, well should say the one was my dads as that is long ago and nothing to do with the oil in that case as it was a cracked head on a low mileage vehicle dad had bought new. The other was a pickup I still have but with a factory new long block I put in after the original engine with quite a few miles on it suddenly started to knock and there is a back story to that and guesses as to what lead up to the engine wiping out a connecting rod bearing and yes I drove it home carefully as the piston was kissing the head as I had nothing to loose ... a challenge, can I limp it home or do I have to call a tow truck LOL. The bigger worry about engines on the farm is if something in the air cleaner ducting fails and the engine ingests field dust, or an injector fails and would damage a cylinder. Oil related would be trying to turn over an engine in too cold a temperature with the wrong grade of oil, not the oils fault but the fault of using an oil in a condition it was not designed to operate in unless it was artificially warmed up by block heater and pan heater before it was started as I have certainly heard of turning crank or rod bearings by turning over a cold engine. That was why I switched over to 0W-40 for all my diesels that might be expected to be used during the winter while running 15W-40 in all other diesels that never get used during the winter. Knock on wood I never had a bearing turn while starting during the winter. Just another issue that Texas would not have to deal with thankfully and wish I didn't either.  

 

A friend of mine used to have a salvage yard, in fact a vehicle salvage yard and a scrap steel yard ( two separate entities ) but where his vehicles often came from were ones that some shop worked on and the owner could not pay the bill so the vehicle sat there and would be a total loss to the mechanics shop, the other were all the broken down vehicles sitting in peoples yards in town and the city ordinance forcing the owner to get it out of there and so my friend also had tow trucks for his vehicle salvage business and would pick up said vehicles either for nothing or get paid a bit and then keep the vehicle for salvage. It sure can be a scum bag underworld though dealing in salvage and some of the people that would come for parts and the real winners my friend would hire as that was all on him, that's a whole other story LOL. Of course here one is dealing with rust on older vehicles so its not like its a nice looking vehicle with a mechanical issue unless one is dealing in newer iron on wheels.  

For many years I was Amsoil only. As soon as possible after purchase my trucks got Amsoil in everything. I did my own service. I went extended. I drove at least 50K miles a year. I pulled heavy with my one ton diesels. When they started coming from the factory with synthetic I just used it. About the same time I started letting them do the service. I still went extended. That changed when I got my first cylinder deactivation truck joining this website. In 2014. Reading several threads stating if you want these newer vehicles to last don’t follow the manufacturer recommendations. At my older age I was neive enough to believed the manufacturers. We did in the 1980s oil analysts with Amsoil going extended. Found no issues. What changed was engines. Strangely enough the most trusted vehicle manufacturers were going extended. So it can get confusing. I figured what the heck. I’ll just half the service schedule and go with their extreme schedule. Hyundai pretty much told me that’s their recommendation. They were the only one. Honda and Toyota said the opposite. I don’t like any of the newer vehicles. Too much technology, too intrusive so I’m running more miles and buying older vehicles. So more frequent oil changes can’t hurt. 

[Chuck FB]

1 hour ago, KARNUT said:

For many years I was Amsoil only. As soon as possible after purchase my trucks got Amsoil in everything. I did my own service. I went extended. I drove at least 50K miles a year. I pulled heavy with my one ton diesels. When they started coming from the factory with synthetic I just used it. About the same time I started letting them do the service. I still went extended. That changed when I got my first cylinder deactivation truck joining this website. In 2014. Reading several threads stating if you want these newer vehicles to last don’t follow the manufacturer recommendations. At my older age I was neive enough to believed the manufacturers. We did in the 1980s oil analysts with Amsoil going extended. Found no issues. What changed was engines. Strangely enough the most trusted vehicle manufacturers were going extended. So it can get confusing. I figured what the heck. I’ll just half the service schedule and go with their extreme schedule. Hyundai pretty much told me that’s their recommendation. They were the only one. Honda and Toyota said the opposite. I don’t like any of the newer vehicles. Too much technology, too intrusive so I’m running more miles and buying older vehicles. So more frequent oil changes can’t hurt. 

I was a kid but believe it was sometime in the 70's when my dad started using a bit of multi grade oil as in 10W-30 and that would have been a diesel/gas rated oil. Prior to that it was straight grades and that was the norm and running 30 weight during the summer and sometimes using 20W-20 and during the winter 10W in select vehicles but in equipment it was the good ole propane tiger torch with a stove pipe under a tractor or truck to warm the oil up, just how things were done back then. It was myself into the 1980's that I started digging for better flowing multi grade oils and back then there was no such thing as Mobil here, it was Esso and they had recently came out with a 0W-30 oil which was also a diesel/gas rated oil as well as a part synthetic 75W-90 gear oil I started using and a semi synthetic gear/hydraulic/trans oil for tractors. Esso had a booklet they published for the Canadian market called "The Cold Wars" and that contained information of their new products designed for the Canadian cold climate for heavy equipment. Some years later they came out with the full synthetic 0W-40 for heavy duty diesels. There are still part 45 gallon barrels in storage sheds on this farm of 20W-20 and probably some 30 as well, way past their due date !. 

 

I never did on most pieces of equipment or vehicles extend the oil change period and part of that is habit but part of that is the fact that on a farm one is in the dirt or driving on dusty gravel roads which a small amount will find its way through the air cleaner, and farming is seasonal so its having equipment ready to go without having to change oil in the middle of a busy part of the season. And back in the day the oil change schedule for diesels was based on high sulphur fuel so no doubt those same old engines could be run quite a bit longer on an oil change now simply because of the ultra low sulphur fuel however the oil would not get changed yearly then based on hours. 

 

Like you I don't like all this intrusive technology in todays vehicles, tracking ones every move and that includes ones cell phone. But its forced upon a person anyway and as I have mentioned before its hard to find a good older used vehicle  because if its lived on our winter roads its turning into a bucket of rusty bolts. I was not excited about GDI but so many vehicles are going to that and as its been said by those who work with oils that fuel dilution ( cold winter starts and short runs would really be bad ) as well as more abrasive soot being created by GDI vs port injection ... who knew gas created soot, but not all good things. I did not want the cylinder deactivation with the issues that GM seems to have with them so here I am with an HD truck, that wasn't my only reason to get an HD truck but it helped push me in that direction. 

 

This is getting long here but I've meant to voice this for a while now on here and I wish I would have way more actual data and what it was that was failing on these L8T engines but a neighbours brother inlaw had been working for a GM dealership until a few years ago and the L8T had been out for only a year or more at the time he quit at the dealership and went somewhere else. But during that time he saw an oilfield companys fleet trucks with the L8T come through with issues ( again I don't know what was happening but it must have been fairly major ), that oilfield company had been running the prior 6 liter GM and they ran and ran with horrible oil change maintenance and the typical piles of idling time as well. So this mechanic said as per my second hand information, the L8T could not hang together with such crappy oil change periods. Of course that lack of maintenance is that companies fault but interesting in a sense that in such an abuse situation the new engine can't compare to the older technology. 

[diyer2]

I'm  still doing oil changes at 72, will continue until I can't. Our daily driver and the new SXS have all Amsoil fluids, Wix oil filter for the daily and OEM for the SXS for know.

[Pryme]

On 9/17/2025 at 4:07 PM, Chuck FB said:

That is what I have at least read as well as to the Kirkland brand being manufactured by Warren oil. A little while back Lake Speed J did a test and I can't recall if that was an engine test or a lab derived test on Walmart synthetic and another name brand oil ... I would have to go back to see what brand was being compared but the results between those two oils and the type of test performed did not put the Walmart oil in a bad light at all. 

 

As to the cost to you in the states at Walmart, that in today's world is one inexpensive oil change considering the volume of oil the L8T holds ( which is similar to the half tons these days ) , so 29.00 for oil and the cost of the filter. At a price point like that it doesn't make one feel bad to change the oil more often than if one was running an expensive oil and felt compelled to run it much longer just to justify itself. 

 

Forgive me if I still cringe at the name Fram but I do realize they make certain filter models much differently than the basic filter they have had around for years with the cardboard ends. That type of filter I would not knowingly put on anything of importance and my worry would be winter time with the extremely thick oil as even with the bypass the oil pressure may build up higher in the filter ( which is a good question, never seen an extreme cold filter test done ). For the fun of it I looked up my truck on the Canadian Tire website as they sell filters and probably because the L8T takes the same filter the half tons and the L5P duramax takes, its a popular filter. They handle a lot of Fram filters along with some other brands but in the Fram line they only have the Ultra Synthetic XG10575 assuming that is the same as the filter you have bought ? and its priced at 16.00 which ends up being similar if not more to the price I pay at GM for a Delco filter. 

The fram ultra is a great filter.  I run that on other vehicles I own without issue. But the new endurance is actually a step up. And is taller. The xg ultra for the truck is a lower profile filter and shorter than the acdelco pf63 so I found that odd. But the new fram endurance is the same height as the pf63. The xg was 10.00 and it was 12.00 for the endurance. 
 

both of the aforementioned filters are worlds better than the orange can fram with paper ends. That’s junk. 

[Chuck FB]

1 hour ago, Pryme said:

The fram ultra is a great filter.  I run that on other vehicles I own without issue. But the new endurance is actually a step up. And is taller. The xg ultra for the truck is a lower profile filter and shorter than the acdelco pf63 so I found that odd. But the new fram endurance is the same height as the pf63. The xg was 10.00 and it was 12.00 for the endurance. 
 

both of the aforementioned filters are worlds better than the orange can fram with paper ends. That’s junk. 

Some farm equipment dealers over the years have had a filter display with cut open filters and of course its to sell their New Holland or John Deere etc filter vs something else like a Baldwin etc. I am sure that one of the dealers had one of the famous budget Fram filters displayed to scare the crap out of the farmers LOL. 

 

Fleetguard brand filters is what I have used a fair bit over the years on some equipment as they have traditionally been a quality filter but they don't always make filters for every application and they tend not to be sold in the retail market but more farm and industrial market. I would have to do some digging to see who handles a higher end Fram such as the endurance. What I won't do personally is try sourcing what appears to be a GM filter online by some suspect outfit .. so much counterfeit Chinese knock off crap of all description on the market these days. 

Edited September 19, 2025 by Chuck FB

[Grumpy Bear]

On 9/17/2025 at 5:26 PM, Chuck FB said:

Oh, I sort of flew past the actual point now which I gather was seeking out Euro spec oil which I presume then does not meet the Dexos label, but yet does meet the requirement to not self destruct a GDI engine ?. I've never figured that out in the last years, how any of that makes sense that there is a Europe spec that would protect GDI engines and yet somehow that isn't proper by GM specs to use in their engines so they had to create their own set of specs ?. So is it the "40" aspect of those oils that you have oil sample results on that are better than the 5W-30 spec that is the highest viscosity typically on the American market that covers the Dexos 1 theme ?, other than GM's own packaged 0W-40 which they throw at the 6.2 in an effort to hold those engines together longer. The 40 grade Euro oil does exist up here but would be handled in a lot more limited volume from what I have seen so far, again can't comment on Walmart until I meet the greeter 

 

Sorry this took so long. I've been sick...so....what have we got?

 

Bold line first. Euro Spec C3 oils have a higher HTHS value which is pro wear but anti MPG and as the motor is 'qualified' for the EPA with a 2.9 cSt HTHS oil the 3.5 cSt HTHS oil doesn't fit the DEXOS spec. Stupid! Two ways to skin this cat. 1.) Use a *W30 C3 qualified Euro oil if you feel saying in book grade is important for some reason. OR 2.) Use a *W40 oil whose actual HTHS spec minimum is 3.5 cSt. 

 

Red Line next. Yes. The oil I use has an HTHS value of 4.4 cSt. Red Line HP Euro Spec 5W40. I could use the 5W30 and did for quite some time (3.6 cSt). Both oils are LSPI friendly and run ridiculously clean.

 

In another post I suggested Castrol or Mobil 1 Euro Spec offerings of there 0W or 5W40. Both have HTHS values right at 3.6/3.7 cSt. But there's a catch and why I say the *W40 and not the *W30. They do not use a 0-5 SSI polymer like Red Line so shear down quicker. They are SAE30 in a few hundred miles then say put for awhile. Depends on your OCI. 

 

Lots of moving parts.

 

High shear polymers got popular for two reasons. Made a 5W30 look like a 0W20 in EPA economy testing AND they are dirt cheap. VM additives are the weakest link in the chain. A full grade in an OCI. Why I HATE Dexos 0W20. That and it isn't as clean as the claim at the OCI they call out. Shell game. 

 

It's all I got for ya Chuck. Happy motoring 

 

 

 

 

 

Edited September 19, 2025 by Grumpy Bear

[OnTheReel]

2 hours ago, Chuck FB said:

I would have to do some digging to see who handles a higher end Fram such as the endurance.

Champion Labs makes the Endurance. It’s a Walmart exclusive but seems to be losing some shelf space to the Purolator 20k (another exclusive).
 

In the applications I’ve run them in, the Endurance is basically a relabeled Royal Purple / Amsoil. Which is to say it’s very nice. The Ultra is great too. Very efficient. Slightly thinner / light construction than the Endurance though.

[diyer2]

What about Wix XP filters?

[Pryme]

47 minutes ago, diyer2 said:

What about Wix XP filters?

They used to be my go to. Then their head got too big and basically doubled the price so I looked elsewhere. 

[OnTheReel]

48 minutes ago, diyer2 said:

What about Wix XP filters?

The XPs are too focused on extended drain intervals. The regular Wix is actually much more efficient (and cheaper).

[diyer2]

Agree Reel.

I have used Wix oil filters many times.

[Chuck FB]

13 hours ago, Grumpy Bear said:

 

Sorry this took so long. I've been sick...so....what have we got?

 

Bold line first. Euro Spec C3 oils have a higher HTHS value which is pro wear but anti MPG and as the motor is 'qualified' for the EPA with a 2.9 cSt HTHS oil the 3.5 cSt HTHS oil doesn't fit the DEXOS spec. Stupid! Two ways to skin this cat. 1.) Use a *W30 C3 qualified Euro oil if you feel saying in book grade is important for some reason. OR 2.) Use a *W40 oil whose actual HTHS spec minimum is 3.5 cSt. 

 

Red Line next. Yes. The oil I use has an HTHS value of 4.4 cSt. Red Line HP Euro Spec 5W40. I could use the 5W30 and did for quite some time (3.6 cSt). Both oils are LSPI friendly and run ridiculously clean.

 

In another post I suggested Castrol or Mobil 1 Euro Spec offerings of there 0W or 5W40. Both have HTHS values right at 3.6/3.7 cSt. But there's a catch and why I say the *W40 and not the *W30. They do not use a 0-5 SSI polymer like Red Line so shear down quicker. They are SAE30 in a few hundred miles then say put for awhile. Depends on your OCI. 

 

Lots of moving parts.

 

High shear polymers got popular for two reasons. Made a 5W30 look like a 0W20 in EPA economy testing AND they are dirt cheap. VM additives are the weakest link in the chain. A full grade in an OCI. Why I HATE Dexos 0W20. That and it isn't as clean as the claim at the OCI they call out. Shell game. 

 

It's all I got for ya Chuck. Happy motoring 

 

 

 

 

 

The main thing is your health, my questions on oil are waaaay down the list of importance !. 

 

The over all picture you draw with the Dexos theme and certainly the 0W-20 due to it sheering down to what may very well be a critical point of engine damage depending on its use case in time and engine type ( and the Dexos 30 grades not staying in grade either ) , that certainly points to bs politics and not sound mechanical engineering practices. And one wonders why so many engines fail these days adding that to cylinder shut off systems and turbos cooking the oil in high strung small displacement engines as well as turbo failure. Which reminds me, Toyota and their 0W-8 , I wonder how that will play out in the long run. 

 

I went to the Red Line website to see who retails the oil around here and they didn't list anyone, I have seen the odd bottle of gear oil on shelves over the years but not engine oil, I imagine its not a fast moving product due to the pricing. Never the less I will look and ask at a few places over the next while to see who has what or can get it in. 

 

I am just speculating that the benefits of a higher viscosity and higher quality oil such as Red Line would give the best best bang for the buck during the summer ( a northern Canadian summer that is ) if towing and pushing the rpm as well as the oil temps, aside from the likelihood of the oil package lasting longer. Low ambient temps and low demands from the engine perhaps not as much benefit ?, that is conversely as long as the typical Dexos slop is changed often enough before it does break down too far. 

[Grumpy Bear]

2 hours ago, Chuck FB said:

I am just speculating that the benefits of a higher viscosity and higher quality oil such as Red Line would give the best best bang for the buck during the summer ( a northern Canadian summer that is ) if towing and pushing the rpm as well as the oil temps, aside from the likelihood of the oil package lasting longer. Low ambient temps and low demands from the engine perhaps not as much benefit ?, that is conversely as long as the typical Dexos slop is changed often enough before it does break down too far. 

 

Where you live getting a supply for this brand might not be doable. That is as long as price remains a high priority. I expect AMSOIL wouldn't be much better on that front. Sort of why I mentioned the Mobil and Castrol Euro 40 weights. A good hedge on viscosity and likely a much better price point. 

 

The the line in bold quoted above: Cold weather performance is a major asset for PAO based oils. 

 

I don't know the Canadian market so no idea what you have available that doesn't suffer the tariff taxes. I mention this as there are some European suppliers with some sold PAO offerings as well. Ravenol and Motul. 

 

All of these suppliers have a rainbow of chemistries available. Red Line for instance has a "Professional Series" which is on par in chemistry with Mobil 1. AMSOIL has the OE Series also a Walmart type Group III backbone product. So when you are considering look up the data sheets and make sure that what you are getting is what you are expecting. 

 

 

[Black02Silverado]

You could use AMSOIL's ATM 10w-30, it has the best NOACK out of the Signature Series and would work well even in your cold weather.  It's another option and AMSOIL has distribution centers in Canada. 

 

https://www.amsoil.com/p/amsoil-signature-series-10w-30-100-synthetic-motor-oil-atm/?zo=521390

 

Also here is the look-up guide for all the fluids for your truck.

https://www.amsoil.com/guides/?zo=521390