Seems a lot of people actually use different oils so I'm curious to everyone's opinion, I live in New York, and use 5-30, but apparently Mitsubishi recommends 5-20 for 04 models

 

I've always put 5-20 in mine...

 

5w-30 here

 

Is there any real difference between the two? I've read a guy in Puerto Rico running 0w-20. I just want to know which is the optimum viscosity, if theres any difference at all

 

5w30 full synth Mobil 1 here in my 2004. Been like that for like 90k miles, and you shouldn't need anything else.

The 5w20 recommendation in the 2004 manual was a misprint.

 

Always ran syn5w30 mobil 1 since day 1. My manual says it calls for 5w30.
Talking to RRM for turboed applications they recommend 20w50 they say our cars oil pump picks up the thicker better.

 

So use 5W20 like Mitsu recommends. Period. Nobody is more knowledgeable about what oil weight is appropriate for the car than the Mitsu engineers who designed it.

 

And that's the truth.... WITH SOME CHEESE ON IT.

 

You do have to remember though after manuals are released things change. At my shop our system gets upgraded constantly with new manufacturer specifications for vehicles. Ill pull it up and double check.

 

According to the dealership mechanic, they were still running 5-20 as of January '12....

 

Optimum viscosity is what the manufacturer tells you. The manual says 5w-30

*If in harsh cold weather maybe try 0w-30

 

So this begs the next question...

Did Mitsubishi distribute 2 different manuals? Ones that say 5w30 and others that say 5w20...? Lol it seems that the left hand doesn't know what the right one is doing with a lot of things that come up...

 

IIRC there was an error in some manuals...im completely sure about it but i kinda remember reading it here

 

5W30 Mobile 1 Full Synthetic

 

I use 5w-20 if I can find it, 5w-30 if not. Doesn't seem to make a difference to my car, as long as it's full of clean oil, it's happy.