Oil

[Willyone]

I'm leaving tomorrow AM for GA and towing back a U-Haul enclosed trailer with a new to me Motorcycle in it. Truck only has just under 4,000 miles on it but to be on the safe side I stopped by a quickie Valvoline place for an oil change. Told the kid I wanted synthetic oil. Kid told me GM specifies synthetic only, for oil. Never knew that.... but there's allot I don't know.

[Krusty]

That's a good thing - doing a decent tow when the rig is pretty new........

 

Dexos1 baby..........

 

http://www.acdelco.com/auto-parts/vehicle-maintenance/lubricants/synthetic-motor-oil-dexos1.html

[newdude]

The 2011 to 2016 Generation 1 Dexos1 is a synthetic blend. GM is superseding the Gen 1 with the new Generation 2 Dexos1 oils. The Gen 2 oils are full synthetic, and replace all of the Dexos1 generation 1 oils. Every dealer should have it in 5w30 already, and they are switching the 0w20 at the moment.

 

BTW...you know you could have gone to the dealer and used one of your two free Chevy oil change/tire rotations that come with the truck right?

[Steve.Z71]

The oil life system is set up for 7,500 miles which is one reason why gm wants you to use full synthetic. You wouldn't want to go that many miles on conventional but I like synthetic better anyways since it holds up better.

 

Sent from my SM-N920V using Tapatalk

[redwngr]

2017 sierra owners manual:

 

Engine oil meeting the dexos1™ specification of the proper SAE viscosity

grade. ACDelco dexos1 Synthetic Blend is recommended.

And:

Viscosity Grade

Use SAE 0W-20 viscosity grade for the 5.3L and 6.2L V8 engines.

Use SAE 5W-30 viscosity grade for the 4.3L V6, and 6.0L V8 engines.

[Cowpie]

I have done a little bit of research and listened to some official GM presentations on the next gen dexos1 and have not come across anything that says categorically that it will require a full synthetic. focus seems to be primarily as a stepping stone to the new ILSAC GF6 spec which should be out soon. And eventually moving towards a higher use of 16w base oils, with fuel economy being the prime motivator for that. While the specs are indeed a lot more stringent than the current dexos1 specs, I have not heard or read a peep from Angela Willis, who is the manager of the Fluids Engineering Group for GM, that the next gen dexos 1 can only be met with full synthetic. But to be fair, less than high end conventional base oils probably will not be able to make the cut. The major aspect to the new spec centers primarily around the additive package that is blended into the base oil itself. That comprises nearly 20% of any motor oil you buy. Folks get all hung up on the synthetic vs conventional vs blends debate that they seem to forget it is the additive package that make any oil do it's job. And any base oil will fail to get the job done with a lousy add pack.

 

The new HDEO diesel spec, CK-4 and FA-4 which is already out and, except that it centers around diesels, mirrors the goal of the next gen dexos1 for gassers. And all the majors have syn blend oils that are meeting the new HDEO CK-4 and FA-4 specs quite comfortably.

 

Either way, it is all academic. Just use an oil now that meets the current dexos1 spec and don't get all caught up in the internet and marketing hype, or take for granted a quickie lube shop tech has it all figured out. And many syn blends can easily go the distance of 7500+ miles and beyond. There are even some limited number of conventional oils that can do that and not fail. If a conventional cannot go the distance, you will have to convince Detroit Diesel that they can't. They currently have (and for some time now) a 50,000 mile oil change interval recommendation for their 15L engine on just plain old conventional 10w30 CJ-4 oil. Sure, it has a larger sump, but the turbocharged motor is 3 times as large as the 5.3L, with 5 times the torque (minimum) and is doing a heck of a lot more work per liter of engine than we will ever put our pickups thru. And those engines are running mountains, hot deserts, some fairly extreme cold, etc on a daily basis around the country moving up to 80,000 lb of truck and cargo.

 

A little known factoid.... the 0w20 does not use a 20w base oil. In most cases, it is a 16w or less base oil. The viscosity modifiers make it act like a 20w at full operating temperatures. So those that might get all hyper about GM moving toward 16w oils might consider that. Essentially, GM already has made the move in recommending 0w20 oil be used. They just aren't disclosing all the details.

[Georgia1911]

...

 

A little known factoid.... the 0w20 does not use a 20w base oil. In most cases, it is a 16w or less base oil. The viscosity modifiers make it act like a 20w at full operating temperatures. So those that might get all hyper about GM moving toward 16w oils might consider that. Essentially, GM already has made the move in recommending 0w20 oil be used. They just aren't disclosing all the details.

 

The minimum viscosity for SAE 20 weight was raised about 5 years ago.

 

For those concerned about modern "lightweight" oils, 20 is hardly a new thing. The service manual for my 1956 Oldsmobile calls for straight 20 or 20W weight oil, when most drivers would have considered 30 as standard. 10W-30 or 10W-20 were approved as well, but this was before multi-grades were common and I imagine they were greeted by some consumers then just as newer grades are now.

[15_silverado]

So why does the 4.3L V6 use 5w-30

And the V8"s supposed to use 0w-20

 

Is it just for fuel economy BS

 

Can I run 5w-30 in my 5.3L all year round; like the V6 calls for; I don't think there is any difference in the V6 or V8 as far as mechanical engineering talorences or oil supply and delivery. So why the different viscosity recommendations???

[redwngr]

So why does the 4.3L V6 use 5w-30

And the V8"s supposed to use 0w-20

 

Is it just for fuel economy BS

 

Can I run 5w-30 in my 5.3L all year round; like the V6 calls for; I don't think there is any difference in the V6 or V8 as far as mechanical engineering talorences or oil supply and delivery. So why the different viscosity recommendations???

Ever done a course in journal bearing design?

 

How about fluid dynamics?

 

How about tribology?

[txab]

IIRC, some difference is AFM and a variable oil pump

[Black02Silverado]

So why does the 4.3L V6 use 5w-30

And the V8"s supposed to use 0w-20

 

Is it just for fuel economy BS

 

Can I run 5w-30 in my 5.3L all year round; like the V6 calls for; I don't think there is any difference in the V6 or V8 as far as mechanical engineering talorences or oil supply and delivery. So why the different viscosity recommendations???

This is a question that will never get fully answered, only GM knows why. We can speculate that it is for CAFE purposes considering the 4.3 gets better mpg than the 5.3.

 

Under warranty I would stay with what GM recommends. Just so you don't have any issues if something happens down the road.

 

I plan on running 0w-20 as long as I own my vehicle.

 

I have run 0w-20 in my 2002 5.3 that GM states to run a 5w-30 and my UOA's came back the same as when I ran 5w-30. So I got the same protection either way. Did I notice a mpg increase? No. I just tried it to see if it did make a difference. But that is older tech considering these new 5.3's with a completely different oiling system that the ECM controls.

[Cowpie]

I will take a little further into the "gray" area. If I had an engine that called for a 0w20, I would probably opt for a 5w20. A 5w20 has a significantly lower NOACK (burn off vaporization rate) than a 0w20. That could be beneficial to things when we factor in AFM and VVT which can be negatively affected by oil coking and such. The only appreciable difference between 0w20 and 5w20 after that is the cold flow rate..... -35c vs -30c respectively. Now I suppose those living in Calgary Alberta or Fairbanks AK might be righteous about using the 0w20, but most of us can comfortably use a 5w20. And there is no way a dealer or OEM could tell the difference. A used oil sample will not show it. And yes, there are 5w20 oils on the dexos1 approved oil list. At operating temps, there is no difference between a 5w20 and 0w20 viscosity.

 

I guess over the years in my experience, I have become more fond of having as tight of spread between the cold flow rate and the oil viscosity for a number of reasons. I use a 10w30 in my 2006 Caddy that called for a 5w30. Always have. Still runs great. And my 2015 2500 6.0L, the same methodology. A 10w30 as opposed to a 5w30. I am not really into higher viscosity oils like the 40w stuff. I have grown fond of the 30w in most everything I own. My commercial heavy trucks with 13L engines use a 10w30 HDEO. As does my JD Gator and NH compact tractor.

[Cowpie]

So why does the 4.3L V6 use 5w-30

And the V8"s supposed to use 0w-20

 

Is it just for fuel economy BS

 

Can I run 5w-30 in my 5.3L all year round; like the V6 calls for; I don't think there is any difference in the V6 or V8 as far as mechanical engineering talorences or oil supply and delivery. So why the different viscosity recommendations???

 

Yes you could. There are many, many fleets that have 1500's with 5.3L that call for 0w20 that they are using the same 5w30 that they have in bulk at their fleet shops. They are having no more problems than anyone else.

 

This bearing thing and tighter tolerances stuff that gets thrown around is not all it is made up to be. The tightest clearances in any engine are in the 4-5 micron range. Even a 30w oil is thinner than that by quite a bit. Viscosity is NOT thickness. It is resistance to flow. Ask Sir Isaac Newton in the next life and he will explain it further. and the viscosity of a 20 w oil at 100c is about 9.5 cSt. A 30w oil at 100c is about 11.5 cSt. Not a significant enough difference to mean anything. Not when you consider a 0w20 at -35c is 6600 cSt viscosity. Even a 5w30 at -30c meets that flow rate. Doesn't take a science degree to look this kind of stuff up. It is common knowledge. Even Amsoil shows this on their spec sheets for their various oils.

[newdude]

I have done a little bit of research and listened to some official GM presentations on the next gen dexos1 and have not come across anything that says categorically that it will require a full synthetic.

 

The Gen 2 Dexos1 is a full synthetic oil. We've been getting the 5w30 since July in bulk at work. 0w20 is pending for bulk to GM dealers. It is a GF-6 oil two years before the spec takes full effect just like the first gen Dexos1 oils back in 2011 for GF-5. GF-6 calls for improvements in GDI fuel dilution and timing component premature wear, and turbocharged gas engines (targeting low speed pre-ignition issues heavily on small turbo engines). On the LSPI issue, GM has a recall on 2016-2017 Malibu right now for an ECU reprogram and an oil change as they have had LSPI issues on the 1.5 engine and some piston failures. Apparently oil + fuel + boom on these high strung small displacement turbo engines.

[Cowpie]

Cool. Learn more every day. I really hadn't paid much attention to the dexos1 changes probably because I don't concern myself with dexos1 to begin with. None of my GM vehicles get a dexos1 approved oil. Not suggesting anyone else should go that route, it is just that I don't lose any sleep over the dexos1 thing. But still, interesting information nonetheless.

 

Just your description of problems with various engines reaffirms in me their is nothing being made by any OEM today that woos me. I sorely dread the day I have to replace any of my vehicles. I have swore I will keep the Caddy till it dies of body cancer and would rather drop in a reman engine than have to face dealing with the latest stuff in terms of autos. Was online looking at the new Cadillac CTS and after getting into the details on it, I just closed the window. Lost all interest. Will keep the CTS I have.