English: Oregonator equation. Top panel shows solutions ${\displaystyle x}$ (red), ${\displaystyle y}$ (black) and ${\displaystyle z}$ (blue, all on logarithmic scale) on the normalized interval ${\displaystyle [0,1]}$, covering a full period of the limit cycle. Center panel shows the scaled trace ${\displaystyle T\cdot \tau [f^{\prime }(u)]}$ along the solution (linear scale). Bottom panel shows reference time scale (red) and the step size sequence (black, both on logarithmic scale). In the stiff regime, the step size exceeds the reference time scale by approximately four orders of magnitude.