5w20 or 5w30

[Markzrt11]

I bought my 2019 5.7 classic 3 weeks ago. Has 12,000 miles and I did an oil change with 5w20 conventional oil with the mopar spec. I'm wondering if i should stick with 5w20 or switch to 5w30 eventually. Either way I'd probably stick with non-synthetic.

 

[crash68]

You'll probably get a few more resounding this but go with a full synthetic, especially if you live in any cold climate. There is no comparison between the two, anything conventional oil a full synthetic does better and longer. Anything less than 7500 miles on a synthetic oil and your wasting your money.
There are quite a few on this forum that run a 5W-30 with absolutely no issues, and it probably still flows better than a conventional 5W-20.

 

[tidefan1967]

5W30 for sure. Gives you much better oil pressure after the oil temperature warms up and especially if you do a lot of idling which is really bad for the HEMI and may possibly contribute to cam/lifter problems later on. Not worth the risk not to run it. By the way every oil receipt I have for my truck says 5W20 on it.

 

[dls56]

I'm using 5W20 full synthetic. Love the synthetic oil!

 

[68PowerWagon]

I bought my 2019 5.7 classic 3 weeks ago. Has 12,000 miles and I did an oil change with 5w20 conventional oil with the mopar spec. I'm wondering if i should stick with 5w20 or switch to 5w30 eventually. Either way I'd probably stick with non-synthetic.

I am not sure why you would want to run conventional oil? Unless you live waaay down south I would run synthetic 5W20 in the winter & synthetic 5w30 in the summer. And I wouldn't stray too far from what FCA calls for. You don't want to give them any ammunition if something were to happen to your cam & lifters.

 

[ChevySlayer69]

Which conventional are you using? Modern conventional oil is excellent. Pennzoil 5w30 keeps my engine happy and quiet.

 

[Greenham]

I bought my 2019 5.7 classic 3 weeks ago. Has 12,000 miles and I did an oil change with 5w20 conventional oil with the mopar spec. I'm wondering if i should stick with 5w20 or switch to 5w30 eventually. Either way I'd probably stick with non-synthetic.

Not that many care but doesn't the manual say 5w30? I've been a Mobil 1 full synthetic and 8k mile changes. YMMV

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[kurek]

I will never understand peoples' compulsion to defy the manufacturer's recommendation on oil.

Do you think they are trying to sabotage you with a deliberately wrong recommendation? Do you have a concept in your mind that oil quality is directly correlated with viscosity and more is always better? If the manufacturer recommends round tires do you find square ones to spite them?

I'm trying to understand what's happening here..

 

[Tyler Yates]

Full synthetic 5w20. Calls for it in my manual and on the cap. Run whatever the truck specifies.

 

[Rado]

Oil threads never die Well for me I run 100% synthetic and what the manufacture specs call for ! I live up in Maine a couple hrs over the border from Canada so sometimes gets real cold :O , I made my switch from conventional oil to full synthetic in the 90's in mt F150 w/a 302! On super cold mornings it would turn over slowly because of the thicker oil from the cold ! :O When I switched to 100 synthetic it turned over like it was summer, so I was hooked lol What one is better ??? BUT what matters most IMO in just change the oil when called for ! For me I think full synthetic is better in the long run from all I have read ! but who knows :O

 

[CoastyAV8R]

In the owners manual on pg 797 it says a 5.7 in a 1500 should have 5w-20 but if you read on you'll see this:

NOTE: For 2500/3500 trucks with a 5.7L engine operating under a gross combined weight rating of 14,000 lbs (6 350 kg) or greater, SAE 5W-30 meeting FCA Material Standard MS-6395 engine oil is recommended for all operating temperatures.

Why the difference in the same engine? Must be tied to them knowing that a 5.7 in a 2500/3500 is going to get worked harder. I use synthetic oil because of the flow it has when it's cold as many others have stated. That's why I'll use 5w-20 in the winter and 5w-30 in the summer when we tow our travel trailer.

 

[kurek]

The HD 5.7l trucks don't have MDS

 

[R.L.K.]

5W-30 Synthetic

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[Markzrt11]

So 5w20 Synthetic would be ok?

 

[dls56]

The HD 5.7l trucks don't have MDS

MDS is a great reason to run 5W20 IMHO.

So 5w20 Synthetic would be ok?

Yes. 5W20 in

So 5w20 Synthetic would be ok?

Yes synthetic is great and 5W20 is the recommended weight.

 

[Fitz-0518]

Kurek, my POV, your question is fair. The assumption or suggestion that the manufacture has the best interest of the vehicle and the customer in mind is flawed. The manufactures often make a recommendation or set specs that have nothing to do with what is best for the vehicle. Today they are driven by political decisions and socialist rules. CAFE standards, warranty rules, lemon laws etc. The days of the engineers know best and they design and spec the vehicle to last longer, are behind us. They spec the thinnest oil they can get by with. Reduce drag on rotating parts. They spec 80lbs air pressure in the rear tires of 2500 trucks. Less tread resistance. Horrible ride. They let, out of spec parts get into assembly. It is a economic gamble for them. The dealer will fix those that complain. Most will make it to trade in before they fail. MDS gets them CAFE standards as 4 cylinders drag the other 4 cylinders through the firing sequence. Ford's engineering is even better. Engine shuts off at stop light. High speed starter starts it back up when you depress the gas. How does that effect a 5.0 truck engine when it is 115* outside running on low temp thin oil. Got their CAFE rating. Fitz

 

[kurek]

They spec the thinnest oil they can get by with. Reduce drag on rotating parts.

Oh man reduced drag sounds like some awful soshulist plot to make the engine produce more power with less fuel. I hate that! I always fill my crankcase with JB Weld for maximum drag like a real American.

 

[madtrucker2016]

I bought my 2019 5.7 classic 3 weeks ago. Has 12,000 miles and I did an oil change with 5w20 conventional oil with the mopar spec. I'm wondering if i should stick with 5w20 or switch to 5w30 eventually. Either way I'd probably stick with non-synthetic.

5-30 and install a oil catch can on that baby you will be better of in the long run

 

[Burla]

The difference in drag at 12 viscosity versus 9 viscosity at the wheel would be near non existent. FCA even changed spec for the eco diesel for widespread damage caused by thin oil, their fix, go up in weight, why?? Why would that be their fix? Because the **** is too thin.

Now, why not "fix" our hemi's by changing the spec like they did in another application? Because they can't, they have sold you a bill of goods that mds requires 20 weight oil. Now, there is widespread cam and lifters issues that has never been seen before. What was their "fix" for non mds, make the 6.4 use a 40 weight oil full of molybdenum. Well geez, why go thick in eco diesel and non mds hemi but go water thin on mds hemi?

Literally the only thing against running 30 weight is piston slap in cold places. You can opt for 0w30 in those places, but whatever. Learn all of the info and make an informed decision. If you are a "Woke" activist and all up in the gov't agenda, go for it run the thinnest stuff possible, I support that 100. If you have evaluated the problems that plague hemi's and believe the manu has let us down, there is like one move for you, go heavier with the oil choice and perhaps choose an oil that is built out of the government agenda api class.

 

[kurek]

Uhh... Ok. How about if i just use the oil the manufacturer recommends and not worry about conspiracy theory bs?