I use 5w20 (mobil 1 extended performance) as a norm and as speced, but accidently used the 5w30 mobil 1 extended performance jug meant for my jeep by mistake. It only has 60,000 miles. Not a big deal, is it? Btw, I did do a search first but came up empty. Thanks in advance.
Btw it is the 3.3 engine.
I always liked the 3.3 engine, a lot. My father had one in an Intrepid. His 1997 Intrepid called for 5w30 in his 3.3, I wouldn't worry a bit and I'd probably just run 5w30 in it so that you had one oil for both vehicles.
We put over 100k on the used Intrepid and traded it in with 155k trouble free miles on it.