18" or 19"; rim width?; TPMS sending units

[jefla]

I've an '07 S with standard 18" S rims ("8x"18 w/ 57mm offset in front; 9x18 w/ 43 offset in rear). No PASM; Conti SportContact tires. I'm toying with switching to "19 rims.

I read on one of the boards that to cars w/ "19 wheels should also have PASM, so switching to 19 is not advised unless the car has PASM. Now I can't find the posting and am wondering about this. Setting appearance aside, should I put "19 inch rims on my car? I expect a redution in comfort and that the 19s will be less capable of handling road hazards. Will they be a lot less comfortable? Handling that much better?

I'm confused by tire and rim width issues. According to Porsche's Tequipment accessories brochure, Porsche sells three different rear rim widths all mounted with the same tread width tires. These include: "10x"19 rims w/ 265/35 tires (Carrera Sport rims); 9.5x19 w/ 265/35 (SportDesign and others); and 9x18 w/ 265/40 (Boxster S). I assume the combination w/ wider rims but the same tire width produces less sidewall flex, meaning better handling but harsher ride. Also, curbs lurk everywhere where I live and drive (Washington DC), and I suspect a wider rim w/ the same size tire is much more exposed to curb hits. Please comment on this.

Finally, can I easily transfer the tire pressure sending units from my existing rims to new rims that may not have this feature?

Regards,