The difference probably belies in the rigor of the program. It sounds like you are working in a non-engineering based program. In our engineering programs we had 40 hours of class time + lab time per week.
I had a concurrent arts degree at the same time which is was, in comparison, incredibly light workload - though concurrently it took time away.
The only time that I will say was much lighter was in the final year of undergrad - the course load finally lightened up.
N.B. this whole conversation clearly excludes summer.