I wonder how much of this steering issue has to do with how light the Mirage is. My 2015 Mirage has barely more than 80% of the curb weight of the 2006 Scion XA we traded in on it, and they are very close to the same size otherwise.
I'm old enough to remember when power steering was an option that a lot of people didn't want to pay extra for, and there were still a fair number of cars around without power steering when I started driving,and I got to drive a few of those. Some of the heavier ones gave you more feedback from the road than you might have wanted. The lighter the non-power-steering car was, the less the feedback you got, and the less muscle strain you had by the end of a long drive.
View my fuel log 2015 Mirage DE 1.2 automatic: 43.0 mpg (US) ... 18.3 km/L ... 5.5 L/100 km ... 51.7 mpg (Imp)