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.