Edit: in the two charts below, there's a labeling mistake; DRG <-> CTPLT JM6 should be swapped.
By scaling the speed of all XL engines >= 305 by a factor of 1.05, the trough vanishes:
Hoping this modification could make heavy / larger XL engines more viable. You can easily set up new speed caps to match old max speed of different variants. CDA would also get a relative buff compared to 35 t lights.
Edited by Phaesphoros, 20 March 2013 - 04:15 PM.