Compare whatever you like to whatever you like, that was never my point. All 17" rims are not heavier than 15" rims. What someone puts on their car is their choice, I never said anyone had to use the wheels I found to be lighter. But it is not speculation, and experience means exactly nothing when you have the wheel specifications. And if it really has to be about experience, I have in fact run Enkei RPF1's on one of my cars, so I know their specs to be correct.
The statement you made was
all 17" rims are heavier than 15" rims, which simply isn't true.
A 17" magnum wheel is no doubt heavier than a 14" magnum wheel. A 17" Enkei RPF1 is also heavier than a 15" Enkei RPF1. I never said they weren't, in both those cases you're comparing the same design rim to a larger version of that same rim. What I did say is there are 17" rims out there that weigh less than OE steel wheels, which is true. In fact, if a 15x7 rally wheel ships at 27 lbs, lets call actual weight 25 lbs, then you can shave
10lbs per corner by using RPF1's intended for a mustang or nissan 350z and some wheel spacers. Now that is a significant number. You would also be shaving 6 lbs per corner by using regular old 17" torq thrust II's, which I know some people on this board have.
Most 17" rims
are heavier than most 15" rims. But not
all. And if you take your car to the track, saving 10 lbs per corner while decreasing sidewall flex is huge, which can in fact be done by going to a 17" aftermarket rim instead of the stock steelies.
If nothing else, I'm happy that people are wondering how much their wheels actually weigh, since unsprung weight makes a big difference to the performance of their car.