Detect Gyroscope's rotation around a single axis? Like a car game.

Hey there!

I've been trying to detect the rotation of the device around the axis through the center of the screen. I want to roll/tilt the device and get the angle of rotation around that axis. I tried using Input.gyro.eulerAngles.z but it doesn't seem to stay the same when I rotate the device around other axes. Imagine a car game with a steering wheel that uses the gyroscope to rotate. How can I implement this in Unity?