Hey everybody just got a really clean 2003 Hemi so far love that power.However the person I got it from was using 5w20 syn but the book calls for 5w30. Whats up with that. Should I stay with 20 or go with 30?

 

Welcome to DF
If the other owner was using 5w/20 sync oil. I would stay with it. But that is up to you on what you want to use.

 

That year Hemi (and '04, too, I believe) wants 5w-30. Synthetic is your choice.

 

5w-20 won't hurt you, the '04 & '05 are identical except some PCM software changes and one specs the 5-30 and the other the 5-20. I use 5-30 in my '04 but hell my local dealer now uses 5-20 in ALL 3rd Gen gassers regardless of year or engine claiming when Chrysler changed specs for the '05, they did it across the board for previous years as well. Dunno if I buy that or they are just buying bulk 5-20 and not buying 5-30, but the difference between the two won't hurt you.

Now if it were an '06 or newer (MDS) then you really need to use 5-20 for proper MDS operation...

 

Been using 5w-20 since I moved to synthetic at about 8,000 miles. Have 85k now and does not lose enought to add between 5-6,000 mile oil changes (up to 50k, I would lose a quart at about 5K). For me 5W-20 was the right choice.

 

Exactly what I was going to say