5w-30 keeps the

 

MDS from engaging. No, 4.7s don't have

 

MDS. Only '06 and newer Hemis. Man, talk about censorship!

 

5w20 is the only way to go for the hemi. the mds is activated by allowing oil into different passages in the engine adn by using a heavier weight oil you affect how the oil moves thru said passages in the engine.

 

i used 5-30 and made no difference at all

 

Got a '07 1500 5.7/hemi w/16k miles.

Been using 5w20 Mobile 1; but the last time I changed the oil, I drained it out before realizing I only had 5W30 Mobile 1 in the garage. Debated the consequences for a minute, and went ahead and put the 30 weight in.

Been driving for 5k miles now. MDS engages as usual, and no change in mileage. Bottom line: no change at all noted.

One note: I'm in Virginia and it has been a warm summer. Maybe the heat is thinning the thicker 5w30 enought to make it work when it might not otherwise. Maybe the fact that I'm using Mobile 1 (synthetic) made it less of an issue. Dunno.

Yea, I'll go back to 5w20 at the next oil change, but 5w30 for 5k miles didn't seem to affect things under the hood any. FWIW.

 

No 4.7 is not a mds eng only 5.7

 

5w 30 can make the mds mess up use only 5w20 If you use 5w30 it Will set a code in the pcm for wrong oil It knows trust me I have seen it you can use just about any 5w20 even syn but dont use k mart brand (that type) if you use 5w30 and go in and complain about your mds system the will see the code and tell you to change your oil you may not feel any diff in the mds but if there problems the pcm knows

 

I have a 2014 ram 1500 and on Page 689 of my manual it says that you can use 5W-30 in place of 5W-20 if 5W20 is unavailable. I recommend taking a look at the “maintaining you’re vehicle” part of you’re owners manual.

 

Wow, 14 years later lol. Did you register just to post that one little late as all hell tidbit LMAO?