OK, here's what we have in some of the OOB's I've checked :
Egypt OOB-1
Imp HAWK ACC=140 Wpn=2 Whd=17 HEP=54 HEK=54 Sabot= 4 Range=255 EW=7 FC=100 RF=0
HAWK IIIP ACC=150 Wpn=2 Whd=17 HEP=54 HEK=54 Sabot= 3 Range=255 EW=7 FC=100 RF=0
Patriot ACC=140 Wpn=2 Whd=22 HEP=73 HEK=73 Sabot= 4 Range=255 EW=9 FC=120 RF=0
Israel OOB-4
HAWK ACC=100 Wpn=2 Whd=17 HEP=54 HEK=54 Sabot= 4 Range=255 EW=5 FC=100 RF=0
Imp HAWK ACC=140 Wpn=2 Whd=17 HEP=54 HEK=54 Sabot= 4 Range=255 EW=7 FC=100 RF=0
HAWK IIIP ACC=150 Wpn=2 Whd=17 HEP=54 HEK=54 Sabot= 3 Range=255 EW=8 FC=100 RF=0
Patriot ACC=140 Wpn=2 Whd=22 HEP=73 HEK=73 Sabot= 4 Range=255 EW=9 FC=120 RF=0
Japan OOB-5
HAWK ACC=100 Wpn=0 Whd=17 HEP=54 HEK=54 Sabot=14 Range=255 EW=5 FC=100 RF=0
Imp HAWK ACC=130 Wpn=2 Whd=17 HEP=54 HEK=54 Sabot=12 Range=255 EW=7 FC=100 RF=0
France OOB-6
HAWK ACC=100 Wpn=2 Whd=17 HEP=54 HEK=54 Sabot=14 Range=255 EW=5 FC=100 RF=0
Imp HAWK ACC=130 Wpn=2 Whd=17 HEP=54 HEK=54 Sabot=12 Range=255 EW=7 FC=100 RF=0
Jordan OOB-9
HAWK ACC=100 Wpn=2 Whd=17 HEP=54 HEK=54 Sabot=14 Range=255 EW=5 FC=100 RF=0
Imp HAWK ACC=140 Wpn=2 Whd=17 HEP=54 HEK=54 Sabot=12 Range=255 EW=7 FC=100 RF=0
Patriot ACC=140 Wpn=2 Whd=22 HEP=73 HEK=73 Sabot=30 Range=255 EW=9 FC=120 RF=0
US Army OOB-12
HAWK ACC=100 Wpn=0 Whd=17 HEP=54 HEK=54 Sabot=14 Range=255 EW=5 FC=100 RF=0
Imp HAWK ACC=130 Wpn=2 Whd=17 HEP=54 HEK=54 Sabot=12 Range=255 EW=7 FC=100 RF=0
Patriot ACC=140 Wpn=2 Whd=22 HEP=73 HEK=73 Sabot=30 Range=255 EW=9 FC=120 RF=0
US Marines OOB-13
HAWK ACC=100 Wpn=0 Whd=17 HEP=54 HEK=54 Sabot=14 Range=255 EW=5 FC=100 RF=0
Imp HAWK ACC=130 Wpn=2 Whd=17 HEP=54 HEK=54 Sabot=12 Range=255 EW=7 FC=100 RF=0
Patriot ACC=140 Wpn=2 Whd=22 HEP=73 HEK=73 Sabot=30 Range=255 EW=9 FC=120 RF=4
Now looking at this site
Raytheon MIM-23 HAWK
We see the origional HAWK had a 54kg warhead and the Improved a 74kg one. Yet the OOB's don't show any improvement.
So - I'm VERY confused here.