I agree with the wheel mod ... why bother, at least they are rims on the Hybrids ... and I don't think they look that bad, could they look better, maybe but they are shiny . I think someone posted they were 14.6 lbs when they switched rims ... I actually like the 06 rims, I would go for them personally if I ever changed these.

I looked on Tirerack.com and found some rims that fit the 05 HCH and are lighter than stock. I used Tirerack because it was easy not because I have any affiliation with them, although I do like thier site and it has some good info and a large customer rating database for tires.

14" - 4 out of 5 had a weight on the rim page, from 14.5 to 9.3 lbs each

15" - 27 rims available, at least 7 had a weight same or lower with out going to the rim page (too lazy to check out the other 20) ... same range of near stock to 9.3

16" - 42 availible, at least 4 ... the lowest was 12.0

17" - 78 availible, at least 5 ... the lowest was 12.8

18" - 54? available (i forgot) lowest was 15.9 lbs.

so if I take the data from another thread and assume that it is correct, then you double the weight for rotational mass then multiply it by the four wheels. difference is 14.6 - 9.3 = 5.3 x 2 = 10.6 x 4 = 42.4. I think this can be slightly greater if you don't go to much wider tires, since you should lose weight with less sidewall.

How much does rim aerodynamics play? I guess that would depend if you do more city or highway driving. How heavy does the rim and tire need to be for maintaining glides and regenerative braking? Or will the glide sustain longer because they are lighter and you could hold lean burn at a lower pedal pressure from less effort to keep the wheels rolling under load. Will the benefit of improved acceleration be greater than any losses? 10 ... even 5 lbs lighter flywheel can make a huge difference. The theory of 100lbs = 1mpg ... then 25 lbs = 0.25 mpg for raw weight plus benifits of the lowered rotational mass in itself. Of course this all in theory and milking those tenths here and there where possible. And while in theory, doesn't lower profile tires have a higher cold max pressure so in essence you could also raise it higher and get that extra 1 or 2 mpg. I wish I had the money to test it out maybe someone else can