The torque curve (represented by the upper line) is fairly smooth, with just a few hiccups in the delivery. Just above idle we’re making over 80 pound-feet of torque, which rises quickly to the maximum of 93.45 pound-feet and, despite some peaks and valleys, stays fairly constant up to 4200 rpm. After that, cylinder filling becomes less efficient and torque starts to drop off. As an aside, the horsepower continues to rise slightly because horsepower is torque multiplied by rpm, and the extra rpm more than compensates for the reduced torque. Similarly, the bottom line representing horsepower shows a nice steady climb toward its maximum of 4500 rpm before leveling off.