Same as Manhattan3 but weighted by 8. This heuristic is better with large maps but can miss the solution on small maps as:
d(A,B) = 8 * (|XA - XB| + |YA - YB|)
This graphic show the depth of all evaluated branches.
The differents colors represent each moves as:
Right
Left
Up
Down
The Arrival branch is the grey one with red dots. Each dot is a strokes and the length is display at the end of the branch.