the 2.7 takes 5 quarts. Overfilling IS bad....better a little under than a little over. When you change the oil, leave off half a quart , start the car to circulate the oil, shut off the car and wait about 10 minutes if warm. Then check the oil again and add more oil to bring it to the proper level. The reason is that when you drain your oil, you will still have some of the old oil in the engine/pan, so if you just add 5 quarts right off, you will be over the limit. As far as weight, I use 10W30 all year. A good filter for the money is Puralator. Don't use Fram...they suck.
Former 2001 Chrysler Intrepid SE owner
Currently own a 2012 Ford Focus