HighMileage oils or stay with Dexos 1 ?

[Jworks]

2011 GMC, 5.3, 183k miles. OK, ....I don't know, this may open a bucket of discussionworms. Ha. Here's the issue. I've been following GM's "mandate" to use Dexos 1 oil, 5w30 (Castrol). I'm thinking maybe I should consider a High Mileage oil due to 183k miles. Castrol and Mobil 1 both make HM but both do not display the Dexos 1 label. So....since I'm way past warranty does it hurt anything at all to change to the HM oil? Its not "Dexos 1" but I kinda doubt it will hurt a thing. I'd like some input especially if someone has done this. Thanks

 

[Coastie05]

It won’t hurt anything. Just make sure to use the proper weight oil. 

[Grumpy Bear]

2 hours ago, Jworks said:

2011 GMC, 5.3, 183k miles. OK, ....I don't know, this may open a bucket of discussionworms. Ha. Here's the issue. I've been following GM's "mandate" to use Dexos 1 oil, 5w30 (Castrol). I'm thinking maybe I should consider a High Mileage oil due to 183k miles. Castrol and Mobil 1 both make HM but both do not display the Dexos 1 label. So....since I'm way past warranty does it hurt anything at all to change to the HM oil? Its not "Dexos 1" but I kinda doubt it will hurt a thing. I'd like some input especially if someone has done this. Thanks

 

This biggest difference in a HM oil is in contains some  "Seal Conditioner". DEXOS oils and most shelf oils are "Dry" oils which over time harden seals. "Seal Conditioner" is more times than not, an Ester. Addition will soften the seals over time but will not repair one that leaks or has cracked. Esters also provide some cleaning but these HM oils don't contain enough to solve out hard deposits. Just the soft stuff.  Also a function of an Ester. 

 

Ester's are not 'allowed' as a 'co-base" by license. Weird, right?  A certain amount is allowed as an additive. Bunch of game playing is what it is. It's why HM oils don't have a DEXOS approval. 

 

DEXOS is a license 'with' a specification but is not a specification. Never was, never will be. It's GM's slot machine always paying the house. Use what you like. 

 

 

 

[Z45]

dexos began as an effort for GM to control the oil change market because the Quick Lube Industry was eating into dealer service department profits big time. So they attempted to get other oem’s to develop standards as well and that would make it hard for Quick Lubes to compete because all the oems would be different. GM faced lot of industry push-back, mostly the quick-lube industry and they went to licenses. Still GM it making a ton of money (est'd 30-40 million in 2025) off the license structure as they charge a hefty fee to get oil tested then require a royalty on ALL gallons sold applicable to GM vehicles. 

[Jworks]

17 hours ago, Grumpy Bear said:

 

This biggest difference in a HM oil is in contains some  "Seal Conditioner". DEXOS oils and most shelf oils are "Dry" oils which over time harden seals. "Seal Conditioner" is more times than not, an Ester. Addition will soften the seals over time but will not repair one that leaks or has cracked. Esters also provide some cleaning but these HM oils don't contain enough to solve out hard deposits. Just the soft stuff.  Also a function of an Ester. 

 

Ester's are not 'allowed' as a 'co-base" by license. Weird, right?  A certain amount is allowed as an additive. Bunch of game playing is what it is. It's why HM oils don't have a DEXOS approval. 

 

DEXOS is a license 'with' a specification but is not a specification. Never was, never will be. It's GM's slot machine always paying the house. Use what you like. 

 

 

 

Very informative Grumpy.  Thanks

Edited yesterday at 01:10 PM by txab

[Black02Silverado]

If you want to use a HM oil this would work  

https://www.amsoil.com/p/amsoil-5w-30-100-synthetic-high-mileage-motor-oil-hm530/?zo=521390

 

Edited 23 hours ago by Black02Silverado

[diyer2]

If you don't have excessive oil usage and did regular oil changes to help with sludge, what's the advantage? 

[Jworks]

18 hours ago, Z45 said:

dexos began as an effort for GM to control the oil change market because the Quick Lube Industry was eating into dealer service department profits big time. So they attempted to get other oem’s to develop standards as well and that would make it hard for Quick Lubes to compete because all the oems would be different. GM faced lot of industry push-back, mostly the quick-lube industry and they went to licenses. Still GM it making a ton of money (est'd 30-40 million in 2025) off the license structure as they charge a hefty fee to get oil tested then require a royalty on ALL gallons sold applicable to GM vehicles. 

 

 

I think I've heard this story before.  Thanks Z.   Always something!

[Z45]

Don't know if all will be able to see this.

Valvoline Cuts Dexos Claim from Synthetic Oils

 

https://www.lubesngreases.com/lubereport-americas/11_27/valvoline-cuts-dexos-claim-from-synthetic-oils/

[Grumpy Bear]

https://www.lubesngreases.com/lubereport-americas/10_07/survey-russian-drain-intervals-drop/

[Grumpy Bear]

11 hours ago, diyer2 said:

If you don't have excessive oil usage and did regular oil changes to help with sludge, what's the advantage? 

 

Engines wear. It is unavoidable. So the question isn't if it will wear out but rather WHEN it will wear out. That question is about rate and RATE is a HUGE problem for almost everyone; but not in the way we may think. 

 

Unless there is something drastically wrong with your powertrain, wear is exceedingly slow. It doesn't wear out in minutes or hours or days or months but in years or even decades. Ditto sludge and varnish. Humans are an impatient lot so to see the benefit of a truly superior product you may have to wait a very long time. Most will get bored first and trade before they reap the benefit.

 

Humans are not companionate creatures when it comes to those we do not know. We don't care what happens to the second or third owner as long as it doesn't happen to us or someone we know and actually like.

 

Sad commentary on humans but it is what it is. That thus, then, there is no advantage...to or for you if the above paragraphs adequately describe you. 

 

BUT if you are a buy and hold type and patient enough to reap the rewards of your labors then that thing that is happening that you haven't yet seen, but will; can be abated by such products. Seals harden and leak with time and lots of it. Rings stick after thousands of miles of a slowly building plaque of varnish. 

 

Then there is this. This didn't happen over night and this poor fellow knew when he removed the cover and not one second before.

 

Not "aware' isn't the same thing as "isn't happening". 

 

 

  The above was typical of the Ford 361 and 391 bus motors on Bulk Pennzoil Mineral Oil products on 3K mile OCI's at about 60K miles back in the 60's and 70's at the Anamosa School District when my Uncle took over their maintenance program. 

 

This is Pepper at @ 165K on 5K OCI's using Group IV/V Full Synthetics. 

 

 

HM oils will help the first but not the second. 

 

Then again if one used..... ah, ya know.....