Engine oil grades

[Hendrikjan]

I have 2016 Seirra with 6.2  90,000 miles.  Oil recommend is 0w20. Because of the mileage I was thinking of going with synthetic 10w30, any comments 

[shakenfake]

Continue using 0w-20

[Z45]

Question: Can another oil such as 5W30 that is cheaper and more widely available be used in place of 0W20 oil?

Answer: No. The 5.3L and 6.2L V8 EcoTec3 engines available in the 2014 Silverado 1500 and Sierra 1500 pickup trucks were designed, engineered and validated to run using 0W20 oil. This is the ONLY oil approved for these engines.

[JimCost2014]

Because of the mileage I was thinking of going with synthetic 10w30

 

Why are you considering this? Just curious what you are trying to achieve. 

[Grumpy Bear]

The OP is not following his own post  

 

What does Stribeck tell us about a change in SAE grade?

A = (V*N)/P

 

It tells us the relationship between viscosity, velocity and load versus surface roughness in a very abstract way. The number you see in the diagrams isn't the frictional coefficient but the multiple of film thickness v roughness in a log scale. The Stibeck number. 

 

Now which of the SAE Grade numbers displayed on the container does this apply to? Not a one of them. MOFT matters. We get only a clue when the HTHS number is posted. And kiddo's that number is a minimum value. SAE has no cap on this number. That said there are lower SAE grades that have a HTHS with a greater value than the next highest SAE grade. Any argument that there is but one possible usable oil is based on that SAE Grades MINIMUM VALUE. 

 

I run my Harley's, that "Require" 20W50, on a 10W40 with a HTHS number greater than the 20W50 minimum. I also run Pepper on a 10W30 when it calls for a 5W30. It's the 30 the HTHS is pegged to. I've also run it on a 0W20 that has a higher HTHS then any DEXOS approved 5W30 oil I've seen. 

 

As a rule the higher the number before the W the higher that HTHS will be from that same blenders product line so a increase in first number is an increase in the MOFT/HTHS and adds to the protection while sacrificing the some fuel in that attempt. 

 

The ONLY target the OEM has on grade is the MINIMUM value. 

 

It won't hurt a thing but the wallet an WILL slow wear. Not that this matters to most because the length of time required to measure it is longer than the vast majority of owners will keep a power train. 

 

 

 

[Black02Silverado]

19 hours ago, Hendrikjan said:

I have 2016 Seirra with 6.2  90,000 miles.  Oil recommend is 0w20. Because of the mileage I was thinking of going with synthetic 10w30, any comments 

That is not high mileage.  Maybe back in the early 70's but not today.  Considering you live in the "Great White North"  and 0w-20 has done well, why change?  Winter is just around the corner.  Well a little ways but the summer solstice is 5 days away and then the days will be getting shorter.

[LDM]

I run full synthetic 5W30 in my 6.2L.  0W20 is only for CAFE reasons.  If you want to use a thicker oil, do so, it isn't going to hurt the engine despite all the claims some will make to the contrary.

[16LT4]

After doing some reading and seeing that the V8s in the Camaro/Corvette, as well as the 4.3 in the K2 (with apparently the same AFM parts but much less failures) call for 5w-30, I've switched to DEXOS approved 5w-30 on my 5.3 at its 100k mile oil change.  I'd prefer 0w-30 because I want as low a cold start viscosity as possible.  Oil flow is what cools parts, not oil pressure.   It went 100k miles without issue on the 0w-20.  I noticed immediately that the normal HPFP tick has been reduced.  Across the board of manufacturers and engines, a 5w-30 oil seems to be a great oil to use.  The Ford 5.4 3v guys (those who rebuild the timing sets and don't want to do it again) prefer it over the stock 5w-20 (I'm one of them).  The -20 oils are perfectly fine on a fresh engine with an intelligent, data-based OCI, but add some wear, sludge, or fuel dilution (something a DI engine owner should keep in the back of their mind), and the viscosity of a -20 oil can be reduced to below spec, resulting in loss of fluid film and metal-on-metal love.  A -30 oil, all else being equal, theoretically adds a little extra cushion.  Used oil analysis can't be used to predict the future, only a picture of the past.

 

From actual tests on my BMW, 0w-40 actually has higher viscosity at operating temperature than 5w-40 (using the same brand, Castrol FS Euro), but also better flow during cold NY winter starts.  Oil changes with the 0w-40 show lower TAN than the 5w-40, so I've run that oil almost exclusively for the past 130k miles.  With 190k miles on the car, UOAs continue to show exceptionally low wear metals, oxidation, sludge, fuel dilution, and no measurable oil consumption.  That engine sees zero warm-up before driving in sub-zero NY winters, along with non-stop drives NY-FL and back at the height of summer, and stop-and-go FL Keys driving in August.  I don't use remote starts, and don't idle an engine to warm it up.  I start, hop in, and drive (but keep RPM under 2500 for the first several miles).

 

My ACVW called for 30w stock, and lots of guys switch to 20w-50 because "old engine."  After the engine break-in last year, I run M1 5w-40 Euro due to the high ZDDP level and it meeting ultra stringent MB 229.5 spec for additives.  Engine temperatures have actually dropped about 10*F as a result of the "thinner" oil, and every degree matters on an air cooled engine. 

Edited June 28, 2022 by 16LT4