Sorry I wasn't clear. What I meant was finishing an engineering system major in 2.5 years instead of 3 (And then of course going on to the 2 year masters). So ultimately becoming an engineer in 4.5 years. Possible?
Well if you do finish it in 2.5 years, you're still going to have to wait another half a year before you can enter the Masters program anyway, so really all you'd be doing is sacrificing your GPA for 6 months off - which is fair enough if you wanted to travel without lengthening your degree or something. In either case, you won't be an engineer in 4.5 years, it will still be 5.
But if you were to finish it in 2.5 years, it would all depend on which system you'd want to major in.
You'd pretty much have to overload in your second year, take a summer semester or two and perhaps overload in the first semester of your third year. So overload in all three of those semesters and take one over the summer, take two subjects each summer, or do anything in between.
If you tell me what system you wanted to major in I could look it up for you and tell you exactly what you'd need to do.