The AVL 8-Mode test is a steady-state engine test procedure designed to closely correlate with the exhaust emission results over the US FTP heavy-duty engine transient cycle, particularly in respect to NOx emissions. The test has been used primarily as a research tool.
The test includes 8 steady-state modes. The composite value is calculated by applying weighing factors on the modal results.
The sequential engine operating points are as follows:
|Mode||% Engine Speed*||% Load||Weight factor**|
|* Normalized speed: 0% = low idle, 100% = rated speed
** Relative weight factors, not normalized (they do not add to 100%)
The relative weights of particular modes are represented by the area of bubbles in the figure below: