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

[Grumpy Bear]

1 hour ago, Black02Silverado said:

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

 

There ya go. Didn't know that. 

[Chuck FB]

5 hours ago, Grumpy Bear said:

 

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. 

 

 

I haven't dug into the oil manufactures websites yet for the Euro oils but gather there are flavours of Euro oil that are not compatible with GDI and those that are which makes it more interesting to sort through what is what. Definitely there are some retailers that handle a bit of the Euro spec oils such as Mobil and Pennzoil but not sure on their spec as it makes a persons head go around to stand at a shelf of oil as there are so many jugs that look almost alike but are different viscosities or types just within one brand. Napa I believe handles some actual European branded oils as well. 

 

I have seen some numbers and possibly a graph in the past showing how a true PAO out performs the lesser types of synthetic oils and certainly blows mineral oil off the chart as it doesn't even compare when it comes to the extremes of cold start up and hot operating temperatures all in one formulation.

 

I wish a company like Mobil would list the cold cranking figures or the HTHS test readings but they don't. One item I find interesting about the Mobil Truck/suv 5W-30 is the flash point of 261c ( 502f ) as that is quite  a marked difference higher than for example any of the viscosities but including the 5W-30 Amsoil signature series as I would have assumed it would have been the other way around. Does that mean that flavour of Mobil has some PAO in the blend ?

 

I had not mentioned this in my last comment but when I look up Red line in Canada in a search for product it lists Walmart so I go on that link and while they list some gear oils and engine oils, I get the idea few of any of them actually exist in the store so therefore its the online third party rip off scheme sending product through Walmart. Here is an example and I assume this is not the correct 5W-40 for a GDI and is an Ester anyway but its an example of the price I was seeing ! . I paste in the link and tried it and now they won't list the price, well it was listed at 47.70 per quart, make that make sense ... that would be 382.00 plus tax for the oil itself for one oil change on a gas truck.

 

https://www.walmart.ca/en/ip/Red-Line-Oil-Synthetic-SAE-5W-40-Quart-Turbocharged-Performance-Formula-Fully-Ester-Cars-Trucks-Marine-Extended-Drain-Intervals-Improved-Efficiency-P/6SYSYTR5JRWM?classType=REGULAR

Edited September 20, 2025 by Chuck FB

[diyer2]

Try Amsoil OE. I use it, you will notice a quieter, smoother motor.

[Grumpy Bear]

13 hours ago, Chuck FB said:

I haven't dug into the oil manufactures websites yet for the Euro oils but gather there are flavours of Euro oil that are not compatible with GDI and those that are which makes it more interesting to sort through what is what.

 

Don't confuse Euro Spec oil with Euro Manufacture oil  In Europe they just call it oil. WE call it Euro Spec because the oil conforms to one of many European specifications. Mainly it draws your attention toward the higher HTHS. But not all Euro Spec oils have that as a limit. They also have 2.9 cSt oils that meet certain specs. 

 

Maybe we need to back up a bit and ask what it is you are looking for SPECIFICALLY. (not shouting, emphasizing) What is the project goal? 

[Grumpy Bear]

2 hours ago, diyer2 said:

Try Amsoil OE. I use it, you will notice a quieter, smoother motor.

 

 

This is a good choice.  Better than 99% of shelf oils for HTHS. 

[Chuck FB]

38 minutes ago, Grumpy Bear said:

 

Don't confuse Euro Spec oil with Euro Manufacture oil  In Europe they just call it oil. WE call it Euro Spec because the oil conforms to one of many European specifications. Mainly it draws your attention toward the higher HTHS. But not all Euro Spec oils have that as a limit. They also have 2.9 cSt oils that meet certain specs. 

 

Maybe we need to back up a bit and ask what it is you are looking for SPECIFICALLY. (not shouting, emphasizing) What is the project goal? 

I see what you mean there in the wording of the Euro spec oil, one being north american derived so they name it differently to distinguish while the other is physically blended in Europe for their domestic as well as world wide market. 

 

Really the goal is not a complicated one to explain as its simply to protect the engine when at operating temperature which also tends to be higher during the summer, but also at the same time able to protect the engine upon severe cold startup and allow for ease of proper cold cranking during the winter.  Ambient temperature wise for the extremes we can get to help draw the picture, this summer we had a few days of 93f, while winter time we almost always hit -40f if not colder through a winter in cold bouts and sometimes winter daytime highs of -40f within that but can be colder as the winter before we hit -52.5f . That is some yearly temperature swing as you can see ( don't ask me why my grand parents thought they should move up here when they had a perfectly good place in Oregon ! ) 

 

However that is where there may be an issue of one particular packaged oil that is capable of doing both jobs because those goalposts are so far apart in a climate like we have up here, severe winter temps vs summer. Throw in the sheer issue of some oils that as you have pointed out don't protect like their numbers on the surface would indicate and so one goes deeper into the weeds in the effort to use the correct oil and if that even exists in one bottle for year around use. That was why I at this point and in the theme of trying to stick with the GM warranty aspect coverage, 5W-30 being within the Dexos spec but also certain 0W-30 oils as well having that certified spec. If the 0W-30 didn't sheer down and as per Mobil or the other main line oils go as I suspect they do, I wouldn't have to overthink the choice past that. Mobil states that the 0W-30 can be used in any application that the 5W-30 can be used, but they also don't admit their oil sheers down either !. 

 

So if that makes sense, that was why I initially thought I would do like I have in the past ( although that was with an older oil chemistry 0W-30 which was a thicker viscosity at 100c ) to just run the newer dexos Mobil 1  0W-30 year around but then started having some doubts on that being the best idea and so chose to use the Truck/suv 5W-30 this summer in the thought it may protect a bit better and then switch over to their 0W-30 for the winter.  But are there better products out there for the engines life, I think its safe to say there are ... , just not in GM's little cubical of fuel mileage at all costs and be dammed the wear ! 

[Black02Silverado]

Then AMSOIL's AZO 0w-30 meets what you are looking for, it is a tad on the thick side compared to the 5w-30 and 10w-30 and it's HTHS is 3.07 compared to the other two at 3.11. It's a solid oil and it's pour point is -50℃/-58℉. To me the main concern would be the extreme cold. High temp's that you get would not be an issue.  I run 0w-20 in my 6.2 here on the south east coast with high humidity and temps in the high 90's and heat index of 110℉ with no issues and I tow occasionally a 5klbs 8x20 box trailer. Plus it exceeds dexos 1 gen 3. 

[Chuck FB]

23 hours ago, Black02Silverado said:

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

I agree that the NOACK is excellent on the 10W-30 , however for the more bitter winter time temperatures the 0W-30 of an Amsoil or various other brands has the better cold cranking specs and so switching out to a more winter friendly oil would be the best case scenario for the engine, perhaps not so much for my pocket book due to timing and changing oils well before it would think of needing an oil change. Unfortunately that comes with the territory of such variable seasonal temps and if one wants the best oil for the time of year. More than likely the NOACK ( as it is on the Amsoil 0W-30 ) will be higher on other brands of 0W-30 as well. 

 

Of course all those half tons out there and suv's and cars with their 0W-20 are just peachy keen all year around and never have to worry about what oil is good for what season as its just all great with just one oil viscosity ... as long as one turns a blind eye to to seized engines, damaged lifters and cam or blown turbo bearings ! LOL. 

[Grumpy Bear]

My wife does this . Serves up Impossible burger scenarios . 

 

I don't often see a situation where a 0W* oil would on my horizon. 

 

https://www.advlubrication.com/collections/automotive-lubricants/products/euro-passenger-car-engine-oil?variant=40941311688897

 

This stuff has a pour point of -60C/-76 F and a HTHS of 3.5 cSt. 

 

Impossible cost money.  

[Chuck FB]

9 hours ago, diyer2 said:

Try Amsoil OE. I use it, you will notice a quieter, smoother motor.

Are you sure, I don't know if I would want my engine to run more quiet then it does now as the truck hardly makes any sound unless I am standing more at the rear of the truck to hear the exhaust as its idling. I've been really impressed with how it doesn't sound like much of anything when near the engine other then knowing its running, more like the proverbial well oiled sewing machine as its sits idling and when revved up its exhaust and fan sound as the engine just runs so smooth without any weird misses or ticking. Now had this engine had 0W-20 in it and the oil was to the end of its life and lots of short runs during the winter with fuel diluted oil, that may be a slightly different story and probably not a good one either in the long run. 

[Chuck FB]

29 minutes ago, Grumpy Bear said:

My wife does this . Serves up Impossible burger scenarios . 

 

I don't often see a situation where a 0W* oil would on my horizon. 

 

https://www.advlubrication.com/collections/automotive-lubricants/products/euro-passenger-car-engine-oil?variant=40941311688897

 

This stuff has a pour point of -60C/-76 F and a HTHS of 3.5 cSt. 

 

Impossible cost money.  

I sure hope she doesn't serve up actual impossible burgers ... those things are awful in every way possible 

 

That looks like a fantastic oil, yes it comes with a price even state side but just think, it covers one from Death Valley to northern Canada/Alaska, over to Siberia and down through the Saharan desert. 

 

I was not able to get into the spec sheets the other day like you were on HPL's site as I never signed up is what I am assuming prevented me from accessing that information but through your link I was able to bring up the basic properties page. That is an impressive oil on both ends and certainly outshines most 30 oils on the top end I imagine its a very sheer stable oil. 5W-30 as well as the 5W-40 are all impressive. 

 

Speaking of oil prices and this was the 75W-85 gear oil for the front diff, I believe it was at least 35.00 if not more at the dealer here in Canada. 

[Chuck FB]

3 hours ago, Black02Silverado said:

Then AMSOIL's AZO 0w-30 meets what you are looking for, it is a tad on the thick side compared to the 5w-30 and 10w-30 and it's HTHS is 3.07 compared to the other two at 3.11. It's a solid oil and it's pour point is -50℃/-58℉. To me the main concern would be the extreme cold. High temp's that you get would not be an issue.  I run 0w-20 in my 6.2 here on the south east coast with high humidity and temps in the high 90's and heat index of 110℉ with no issues and I tow occasionally a 5klbs 8x20 box trailer. Plus it exceeds dexos 1 gen 3. 

I missed seeing this comment, yes the 0W-30 and one that doesn't sheer down to nothing is the better all around fit for our climate up here as the highs tend to be in the mid to high 80's as a typical summer extreme ( we did hit 106 a few summers ago but that was a complete outlier ) but unfortunately during the winter we can have -30f for weeks sometimes and the typical dipping into the -40's, its rare not to see at least one day of -40 or colder during a winter. And those are real temperatures, not that fake wind chill spouted off by the weather reporter to impress the audience. The lowest temperature recorded for this area was way back in 1914 at -70f although they state the instrument was more than likely not reading as cold as it really was ... stupid cold anyway. 

 

I understand that in Alaska dealerships will install a "winter package" of one wants and of course a block heater is essential but they put on a engine oil pan heater, possibly a trans oil heater pad and some fluid changes such as the cold weather power steering fluid, electric battery blanket ... its a list of items anyway. I've never been to the Yukon or Alaska during the winter but Anchorage area and south is very different from the central and northern parts as its warmer than here during the winter in southern Alaska. Fairbanks is a different story though as its a cold city but two winters ago we were in a cold pattern and beating Fairbanks day after day for being colder .... and I hate the cold, but I can't handle the heat either so I am basically screwed all the way around !. 

 

If I lived where you do I know I would be very very tempted to run either 5W-30 or 10W-30 in an engine that called for 0W-20 

[diyer2]

I have used Amsoil products in a few things, they were all quieter, smoother, including transmission's.

Try Amsoil, you're quest may be over.

[Grumpy Bear]

I belong to another car site for one of my other marks who has a large Canadian population. I see allot of these fellas actually have a spring/fall switchover maintenance routine that includes a change in oil grade. Temperature swings in your area seem to make it necessary. 

 

 

Edited September 21, 2025 by Grumpy Bear

[Chuck FB]

20 minutes ago, Grumpy Bear said:

I belong to another car site for one of my other marks who has a large Canadian population. I see allot of these fella actually have a spring/fall switchover maintenance routine that includes a change in oil grade. Temperature swings in your area seem to make it necessary. 

Definitely that would depend on what oil is chosen and the location within Canada for sure as southern BC and Vancouver/Vancouver island is vastly different for temps then where I am as an example. The odds are that someone on a forum and be it this one or another automotive forum has a different view point and mind set vs the person who knows nothing about their vehicle nor cares to and relies on everything  done at a dealership or chain automotive shop. In fact it would be interesting to know what percentage of the driving population ever checks their engine oil level, never mind anything else. 

 

But going back to viscosity, that was why long ago I realized that non synthetic 10W-30 for a gas engine or 15W-40 for a diesel just wasn't going to cut for year around use without a risk of causing major engine damage unless the oil was preheated before start up and my switching over to 0W-30 for gas and 0W-40 for diesels that see all seasons and don't have to do seasonal changes on engines that may not have seen much use at all. Due to cost though for all those engines on a farm that never get run during the winter, it still makes sense to go with the less expensive oil blends and these days even the 15W-40 is a part synthetic depending on the brand and the long drain interval claims ( highway tractors ). Back when I was hunting around for better flowing oils some 40 years ago and had bought various products, I took some containers ( not bottles but open containers like ones for sour cream etc ) and marked them and then put in various oils, everything from gear oils to automatic transmission, hydraulic, and various engine viscosities. -40 or colder would hit and these samples were out in a cold storage shed and I could lift up the containers and see how the fluid flowed when tipped on its side or upside down. Non synthetic 10W-30 for example was a sight to see, I could hold it over my head as it just sat there for a number of seconds and then might start to move ever so slightly. Even automatic transmission fluid of the time was pretty darned thick and did not flow well. That was quite the wakeup call though to see how impossibly thick a lot of oils will become.