MapQuest states our frequent trips from CT to NJ should take 3 hours and 14 minutes. The typical time for us is 4 hours but it can range from 3 1/2 hours with no rest stops and no traffic to 6 hours plus if we hit rush hour traffic, general traffic congestion, or road construction along the way. Our trips have been during the week, week-ends, and at all times of day...it's hard to tell how the trip will go.
Just my opinion but while I like MapQuest for directions, I don't think it does a good job of estimating traffic congestion and rest stops; maybe the time will average out for your longer journey. Have a good trip.