5W-30 vs 5W-20

[ThunderbirdJunkie]

Yeah, the MDS needs to have 20wt oil to function properly. it CAN still WORK, but it won't work PROPERLY.

 

[sharpy]

intesting read on MDS HEMI here http://www.asashop.org/autoinc/oct2009/techtips.htm

0w 30 is fine . ive been usin 0w 30 mobile one.

 

[JeepJeepster]

... ahem....

Need to step in here for a minute.

Sorry Troy, but MDS really won't work correctly without 5W20.

How do I know this?

My aunt has a '06 300C.

Went to go get an oil change, and immediately noticed a highway mileage drop. I asked her what kind of oil was used, she said the paperwork said 10W30.

About 2 oil changes later, with 5W20...

All was back to normal.

Yeah I was curious about that too. The MDS uses solenoids to let the lifters collapse. If the oil was too thick I assumed it wouldnt let the lifters collapse like they needed to.

Edit: Looks like sharpys link says the same thing I just did about how it works..

 

[04Liberty]

There is no bulletin for switching all engines to 5w-20.They do have bulletins for ATF+4 and coolant but none for oil weights.

As far as the HEMI's needing 5w-20 for the MDS to work is a crock of s$%t,the engine has no idea what weight of oil is in it and the MDS will work with 5w-30 and even 10w-30.It's a scam just like the oil companies used to pull by saying once you switch to synthetic you could not switch back to dino oil.The whole 5w-20 thing is to comply with CAFE and that is all.

Here is your MDS bulletin. YOU go ahead and get an MDS engine and put whatever oil you want in it....let me know how that works out for you. like I said before, follow the cap or the FSM and you can't go wrong.

 

[tjkj2002]

Here is your MDS bulletin. YOU go ahead and get an MDS engine and put whatever oil you want in it....let me know how that works out for you. like I said before, follow the cap or the FSM and you can't go wrong.

And only applies to '05 5.7's and for only 3 vehicles.

 

[ThunderbirdJunkie]

In 2005, only 3 vehicles had MDS. 300, Magnum, and WK

 

[tjkj2002]

In 2005, only 3 vehicles had MDS. 300, Magnum, and WK

And why it only effected 3 vehicles.

 

[Dave]

MDS.....PMS....our 3.7's don't have any of that crap...

 

[Jeep-I-Joe]

MDS.....PMS....our 3.7's don't have any of that crap...

It really isn't that difficult. #-o The owner’s manual has a friggin chart telling you which oil to use in which temperature range with the 3.7L. (5W-30 or 10W-30) The manual's and recommendations may be different in Canada being it gets so darn cold up there. Is that the case?

 

[Marlon_JB2]

All I know is that all of my KJ and WK manuals have recommended 5W30 year round, in all climates.

CORRECTION: WK manual recommends 5W20 for the 3.7L, reason states "Improved cold weather starting and fuel economy".

 

[tjkj2002]

MDS.....PMS....our 3.7's don't have any of that crap...

Well some seem to have PMS from time to time(naughty)

 

[Ry' N Jen]

I've had PMS all day long!

 

[tjkj2002]

I've had PMS all day long!

TMInono.gif

 

[Dave]

tminono.gif

omg.............

 

[incommando]

Just ran out and grabbed the '05 manual to be sure but... it says to use 5w30 year round and it has no chart for recommended oil at extreme temps one way or the other.

Funny how the same engine, the 3.7, had such varying recommendations from 2002 - 2007 and I don't believe that there were many internal differences. The CAFE answer makes the most sense to me. I would not be afraid to use 5w20 in the winter in a cold climate, but I will stick to 5w30. I have had no sub-zero starting or noise issues.

 

[Marlon_JB2]

I just found the thread.

Big debate? Seems like an everyone else against one thread to me.

Anywho, another reason (besides the rumored "CAFE" excuse) is simply cost.

If one of your engines NEEDS 5W-20, and all of the rest of your engines can durably run 5W-20, then why not just fill them all (or as many as possible) with 5W-20? This way a manufacturer, in this case, Chrysler, can just buy nothing but 5W-20 and save a few pennies doing it? Did anyone EVER think about this at all? No, too busy complaining about CAFE regulations. And how about talking to the Engineers, instead of just random people on forums?

That's what I do.

 

[HoosierJeeper]

Well some seem to have PMS from time to time(naughty)

The engines or the members.....

 

[f1paul]

My owners manual for canada says 5w/30 year round, thats what i use. fwiw.

 

[04Liberty]

You guys will love this...
02, 03, 04, 05 and 06 KJ FSM all say the same thing: below 100 °F 5W-30 (preferred), 10W-30 acceptable 0 °F and up (anyone who calls BS can ask for the page).

 

[ThunderbirdJunkie]

Says that in ThunderbirdJunkie's owner's manual