I went to the same school, and you could get out in 4 years with an engineering degree, but only if everything went to spec. Fail a class, decide you want a minor, decide to do something out of order, or an extended internship and it almost immediately added either a semester or year.
On the flip side Mrs. Selkirk came out in 4 years with BA's in Poli. Sci. and Philosophy and a minor in French mostly because she'd damn smart, but partially because a great deal of her coursework did double duty.
The actual Butt in Seat/Lab class time was ~1.5x longer for Science/Engineering at my University