So my mom was visiting and was checking out under the hood for her, only to find that the car was at least 2 qts low! All had was some 5w20 & I know the 3.5 likes to have 10w30 but some oil is better then none.
In this case, probably no harm done. Better to have the incorrect grade of oil added than to continue to run with low oil level.
On the other hand, adding the incorrect grade of oil to my Hemi w/MDS is a strict no-no. The Hemi w/MDS is designed to use 5w-20 only - any other grade could result in the MDS not operating properly and possible damage.
Just to be safe though, I would recommend an oil/filter change at the earliest convenience.
The remaining question is - how did it get 2 qts low? Any obvious leaks or seapage?