[JTR18SHAKER]

Hi so maybe someone can clarify something for me. I know that the vehicle takes 5w-40 oil (6.4l), as indicated on the filler cap and in the service manual. However when I check the tech-authority shop manual for the vehicle it states as a starred "note" that the 6.4L engine should use 0w-40. I can see the 0w for cold weather starts and at that rating it runs like water. I could also see that the oil at 0w would flow that much faster (? than 5w) to the top of the engine. I have checked with the dealer for a reference and they state to use 5w-40. Thoughts.

 

[cdahl383]

If it were me I'd stick with 5W-40. That's what your owner's manual says and the oil fill cap both say. 5W is already a really thin grade when cold.

 

[JTR18SHAKER]

Thanks Carl, it is the inconstancy with these type of things that concern me. As far as I know the tech authority CD is the same manual as is used by the Dodge Mechanics, it is the 2011 Challenger shop manual.

I have taken an except from the manual that shows specifically the oil recommended for 6.4l engines. If you could take a look under NOTE:, perhaps I am missing something.

 

[cdahl383]

Yeah I see where it says to use 0W-40. Honestly I don't think it's going to make that much of a difference. They're both a 40 weight oil and both 0W and 5W are going to be really thin on cold start up. It's frustrating when you get two differing recommendations from essentially the same source (Chrysler).

You could use 0W-40 in the winter and 5W-40 in the summer. I used to switch to a little thicker grade of oil in the summer in my old truck. But honestly I think either one will be fine.

You could post your question up under the SRT 6.4L forum and see what other members are using just to get a general idea as well.

 

[large]

They changed to 0/40 back in 2013,when I bought my 2014 SRT8 they said to disregard the manual and cap and run 0/40.Pennzoil has made a special SRT oil in 0/40

 

[cdahl383]

There you go, I'd go with what this guys says as he has a newer SRT. Makes you wonder why they didn't update the manual and cap on the actual car itself in that timespan of 2-3 years?

 

[MommaBetty]

This problem reminds me of a similar issue I had with the proper octane fuel. My owners manual that came with the car said use 91 octane in the R/T 5.7 Hemi. Many members said that on the automatic it only required 89 octane. So I guess the full owner's manual gives 91 octane for the manual transmission R/T's and 89 on the automatic. Why was the guide that came with the car different????

 

[jkelly16]

There's discrepancies throughout the owners manual. In fact, sometimes they left the wrong info in the manual and put a card in with the papers that detailed what the changes were. I think this is what happened with the oil. Just double check any light bulbs you need to replace because some of those are wrong to.

 

[boyohboy]

Another Crisis Met and Matched through the Auspices of being on Forum Z! Enjoy the Journey! Lou.

 

[jackal]

Pretty sure the change coincided with Pennzoil release of Ultra Platinum.

http://www.pennzoil.com/motor-oil/pennzoil-ultra-platinum-full-synthetic-motor-oil/#&panel1-2

 

[oilslick]

Either 0W/40 OR 5W/40 is fine.

I like the 0W/40 better because of the better cold start flow.

:4-wavey:

 

[JTR18SHAKER]

Super guys, great posts!

I just find it interesting how the oil viscosity for some engines has changed over the years. Let's say from the forever used 10w-30 to 5w-20 now in most cars. Then you take the 6.4l using a 40 grade, quite thick to me. Is the tooling of the engine different? Blueprinted vs mass production? Don't know myself. But in the long run it is what it is.

 

[cdahl383]

I run 20W-50 in my Nova! That stuff is like molasses right now in the cold weather. It just sits in the garage all winter though until spring. Looser tolerances require thicker oil. The tolerances on these newer engines are really tight and they're also after any way to increase MPG's and thinner oil with less drag/friction in the motor is the ticket.

My Challenger takes 5W-20, that stuff looks like water to me in the summer. I'd feel better running something thicker but it's not an old school engine, so I just stick with what the manual says. Today's oils are much better than they were years ago as well.