I'm not sure that chart is accurate, or if it is Lotus is saying something else.
See...
2009 Lotus Exige 260 : Auto News
Ultra-lightweight wheels, that reduce the unsprung mass and contribute a weight saving of approximately 22 lbs. over the already super-light forged Exige wheels
If Lotus claims are accurate that the forged 12-spoke
Super Lights, as they are referred to on the Exige 260, are all total 22lbs lighter than the 08/09 LSS then that should make them lighter than the weight as shown in the chart for RAC's. Thats subtracting 22 from the weight shown for the LSS in the chart (58.9 lbs - 22 lbs) making them 36.9 lbs compared to the 49 lbs for RAC's . :shrug:
And I can find all kinds of articles that support that claim online too.
I know 08/09 LSS rims got narrower for the 240 and I think are 6 in front and 7.5 rear. The Super Lights are 7 inch front and 8 inch rear.