Engine Oil. 5w20 or 5w30

[Onyx_Hemi]

Hey everyone, new here with a few dumb questions.

I was flipping through my owners's manual the other day (bored in quarantine from this COVID-19 virus)... and I noticed that Dodge recommends using 5w30 engine oil... But in my engine bay, on the oil cap it says 5w20.

I've been running Royal purple 5w20 in my hemi for quite awhile now, but after seeing this in the manual... should I start using 5w30?

Located in Canada, so colder winter climates. Curious what everyone's thoughts might be.

2004 Dodge Ram 1500 5.7 Hemi

Thanks in advance,

 

[HemiLonestar]

SO your cap SHOULD say 5W30 (sounds like your cap got replaced at some point), starting 2005 they switched it to 5W20. Why you ask? MDS 5.7's. The trucks didn't get MDS until 2006, but the 300 & Magnum had it in 2005 and Mopar wanted the same oil weight for the 5.7's across the board. 5W20 was mandated for proper MDS function, I'm not sure why since an automatic 392 with MDS does it just fine with 0W40 but what do I know lol. With a non-MDS 3rd gen 5.7, you can run either 5W20 or 5w30. Straight out of the your 2004 owner's manual; note the viscosity chart, for consistently hotter climates they also list 10W30 (but 5W30 preferred):

 

[Onyx_Hemi]

@HemiLonestar

Interesting enough, a couple of the other 3rd gen's I've owned also had the 5w20 cap, so I don't think it's been swapped out. Also my truck definitely does not have MDS lol.

But that is interesting information, makes sense to have it consistent across the board. I will try switching to 5w30 on my next change and report back!

 

[ST-8]

My 04 doesn’t say anything on the cap either an have seen other trucks that say it, always thought that was odd maybe it’s an 04 thing lol

 

[mcamzr]

The 05 5.7 called for 5/30 on both the oil bay and the owners manual. I worked at a dodge store when the 06 came out with MDS. There was a recall on my 05 and the recall Just gave me a new owners manual and oil cal that both said 5/20. The change was made so dealerships didn’t have to stock two different oils for MDS and non MDS motors. That said I run 0/30 for quicker flow when cold.

 

[alnelson14]

my 05 has 240,000 miles on it. Father in law bought it new in 05, and has ran Castrol 10-40 since new. So i'm going to continue with that. The non-mds engines are a lot less sensitive to viscosity.

 

[HemiLonestar]

The 05 5.7 called for 5/30 on both the oil bay and the owners manual. I worked at a dodge store when the 06 came out with MDS. There was a recall on my 05 and the recall Just gave me a new owners manual and oil cal that both said 5/20. The change was made so dealerships didn’t have to stock two different oils for MDS and non MDS motors. That said I run 0/30 for quicker flow when cold.

Sure about that?

 

[hemihustlin]

I have been using 5w30, 10w30 and 0w30 (all synthetic all pennzoil) for the last 6 years. MDS works great with all of them especially the 0w30, MDS mode activates much sooner after a cold start than with the other oils i have tried.

 

[mcamzr]

I do have both owners manuals from the truck. It was a early build 05. I’ll see if I can find them.

 

[HemiLonestar]

I do have both owners manuals from the truck. It was a early build 05. I’ll see if I can find them.

A month later lol

 

[Old Fart]

I run Redline 5W-30 all year round. No issues.

 

[mcamzr]

Yea. Sorry about the month later.

 

[mcamzr]

And the new oil cap. After the recall

 

[hemihustlin]

Thats what my oil cap looks like. I love how big and well placed it is. With a steady arm you can even pour the big gallon jugs in it with no funnel. How intelligent!