To achieve max torque at 1500 RPM (as advertised) you would need to open the throttle under load from idle. In practical driving, that would be ridiculous.
I usually drop to 4th to make a pass on the highway. I had an experience a few months ago where I passed someone in 6th gear (not realizing it) and the car pulled hard enough that I thought I was in 4th. I didn't realize it had actually been in 6th until I tried to make a 4-5 shift.