Conventional or full synthetic

Grumpy Bear · March 26, 2020

Here's the difference between Shell Rotella T1 Conventional and T6 Full Synthetic.

OCI

People were getting a million miles on gas motors when the SAE service class was SC. They just changed it more often.

MrGraff · March 26, 2020

If ya want a good tried and true oil for the cheaps, goto walmart and grab the Mobil 1 TurboDieselTruck 5w-40. Past that its pretty much whatever your opinion is, me personally I run Amsoil Signature 5w-40 currently, but will be switching it back over to the 15w-40 oil after my first 10,000 miles. If ya go Amsoil.. its worth every penny to buy the yearly $20 membership because itll save you 20-30 every change.

KARNUT · March 26, 2020

If ya want a good tried and true oil for the cheaps, goto walmart and grab the Mobil 1 TurboDieselTruck 5w-40. Past that its pretty much whatever your opinion is, me personally I run Amsoil Signature 5w-40 currently, but will be switching it back over to the 15w-40 oil after my first 10,000 miles. If ya go Amsoil.. its worth every penny to buy the yearly $20 membership because itll save you 20-30 every change.

You’re going to put 15-40 in an cylinder deactivation engine? Keep us updated.

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swathdiver · March 26, 2020

7 hours ago, KARNUT said:

You’re going to put 15-40 in an cylinder deactivation engine? Keep us updated.

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Not for long! These forums are full of posts of folks with AFM problems and the usual common theme on the low mileage ones is that they used the wrong oil, either by weight or not GM approved.

Z45 · March 26, 2020

GM’s approved is scheme to scare customers into bringing their vehicle to the dealer for service. Since that caused a lot of dissension among oil suppliers GM decided to sell licenses. It’s all about making $ for GM.

MaverickZ71 · March 26, 2020

Make sure whatever you use meets the Dexos specs listed in your Owner Manual, in the recommended viscosity and quantity, and change it by the Oil Life Indicator interval, if not sooner. It is my understanding that any motor oil that meets the current Dexos specs has to be "full synthetic". Some on here do their first oil and filter change really soon, with the idea that they're helping to remove any metal shavings, etc, leftover from the manufacturing process.

The GM Dexos II and Dexos-D oil at the dealer are actually top-rated. Some on here fight endlessly for AMSoil, Royal Purple, and RedLine, but those can be hard to find unless you buy online.

If you're running a diesel engine, many on here like Shell Rotella diesel engine oil, or if you're running a gas engine, many on here like Shell Rotella Gas Truck motor oil, both of which are available at discount stores and auto parts stores. I switched to Shell Gas Truck after using Quaker State Ultimate Durability and Pennzoil Platinum.

The new AC Delco "e-core" oil filters (the ones that end with the letter "E") are of questionable construction, with cardboard end caps and filtering material wrapped in a plastic cage--changes made for cheaper manufacturing and easier recycling over better filtering. After much research, I use Wix oil filters now (same as NAPA Gold or Platinum).

Edited March 26, 2020 by MaverickZ71

swathdiver · March 26, 2020

21 minutes ago, elcamino said:

GM’s approved is scheme to scare customers into bringing their vehicle to the dealer for service. Since that caused a lot of dissension among oil suppliers GM decided to sell licenses. It’s all about making $ for GM.

I used to believe that and learned the hard way. My motor was a bit noisy using Mobil One and seemed awfully thin. Then I came across a new oil last year on ACDelco's website for the aluminum LS engines and decided to try some. At the end of the second oil change on the new stuff I sent off a sample to Blackstone for analysis which is posted earlier in this thread. Immediately noticeable was the motor quieted down and she picked up an easy 1/2 mile MPG, especially at low speed.

And to my other point, we have seen on these forums guy with AFM problems attributed to them using oil that was not Dexos approved. Doesn't make sense to me but I don't know oil like the engineers or Marty!

Z45 · March 26, 2020

I don't use dexos approved oil (and never will) and never had one issue with my GM engines. GM Dexos is no more a higher grade oil than GM’s Dexcool was better antifreeze. We know how that turned out. Every time you see the Dexos logo you paid more for it. It’s just another way they extort money from other companies.

Edited March 26, 2020 by elcamino

Grumpy Bear · March 26, 2020

1 hour ago, swathdiver said:

Not for long! These forums are full of posts of folks with AFM problems and the usual common theme on the low mileage ones is that they used the wrong oil, either by weight or not GM approved.

Pepper should have dropped dead by now. 0W20 since early on. Spec is 5W30. No issues, no oil usage.

Red Line, what she's been on most of her life, yea...not approved most of that time. Still not an SN=Plus in the HP line. They have added a black bottle version that is SNPlus and Dexos approved. It is not an ester however. Tis a Group III/PAO.

Many other factors at play and these sorts of fella reporting 'filter' their information to set the table for a cause MOST of the time. Truth is hard to come by me thinks.

Recently went back to 5W30 after completing making a 100K mile point on both damage and efficiency.

Grumpy Bear · March 26, 2020

23 minutes ago, elcamino said:

I don't use dexos approved oil (and never will) and never had one issue with my GM engines. GM Dexos is no more a higher grade oil than GM’s Dexcool was better antifreeze. We know how that turned out. Every time you see the Dexos logo you paid more for it. It’s just another way they extort money from other companies.

For the most part correct. Getting the Dexos license assures you of a few things:

1.) It is a full synthetic meaning Group III or above base oil

2.) Has a NOACK under 13% (SAE spec is 15%)

Your motor won't fall apart if you use an SN Plus Conventional IF YOU CHANGE IT OFTEN ENOUGH.

Edited March 26, 2020 by Grumpy Bear

swathdiver · March 26, 2020

12 minutes ago, Grumpy Bear said:

Pepper should have dropped dead by now. 0W20 since early on. Spec is 5W30. No issues, no oil usage.

Red Line, what she's been on most of her life, yea...not approved most of that time. Still not an SN=Plus in the HP line. They have added a black bottle version that is SNPlus and Dexos approved. It is not an ester however. Tis a Group III/PAO.

Many other factors at play and these sorts of fella reporting 'filter' their information to set the table for a cause MOST of the time. Truth is hard to come by me thinks.

Recently went back to 5W30 after completing making a 100K mile point on both damage and efficiency.

Marty, you're the exception because your choices have been well thought out and also tailored to your driving profile.

I guess my Blackstone report doesn't mean much to Mike.

Grumpy Bear · March 26, 2020

7 minutes ago, swathdiver said:

Marty, you're the exception because your choices have been well thought out and also tailored to your driving profile.

I guess my Blackstone report doesn't mean much to Mike.

Given all the forum crying the mileage on your truck alone speaks for both itself and its owner. Don't worry about what others think.

TXGREEK · March 26, 2020

Why go conventional in an unconventional world, why go part (full Synthetic) synthetic when you can go 100% Synthetic!

Amsoil 100% Synthetic is the best oil for engine protection, the rest is snake oil.

Sent from Above

Grumpy Bear · March 26, 2020

58 minutes ago, TXGREEK said:

Why go conventional in an unconventional world, why go part (full Synthetic) synthetic when you can go 100% Synthetic!

Amsoil 100% Synthetic is the best oil for engine protection, the rest is snake oil.

Sent from Above

There we go. Wondering how long this would take.