Today I got a chance to weigh the HRE wheels vs the OEM 351M wheels with tires.
And the difference is significant, here's the numbers (kg/lbs)
OEM 351M
28.7/63.3 + 28.9/63.7 + 29.9/65.9 + 30.2/66.6 = 117.7kg/259.5lbs
HRE
22/48.5 + 21.9/48.3 + 24.5/54 + 24.5/54 = 92.9kg/204.8lbs
So the much bigger HRE wheels are 24.8kg/54.7lbs lighter.