I have an '06 Boxster S with the 19" Carrera S wheels. They really looks great, but I don't want to replace the tires or chip/scratch the wheels. So I'm thinking about going with some 18" Turbo Twist wheels from a 996 4S. I"m wanting to replace the wheels to the smaller diameter because the tires are cheaper and I want the 18's for track days.
The specs for the 18's are: 8 x 18 ET50 Front / 11 x 18 ET45 Rear. The Hub Size is 71.5 (If you need to know)
Will there be a problem going to the 18's in this configuration? I need to know if I'll have fitment issues and will I need spacers and what size? If any of you can give me any feedback I'd really appreciate it!

 

The fronts are no problem (with 235/40-18), the rears will be a VERY tight fit. With 11"x18"ET45 you would need at least a 285/35-18 or a 295/30-18. I have had both tire sizes on my Boxsters, but on 10"x18"ET40 rims. With the ET45 your wheel will be 5mm closer to the suspension strut than my ET40 rims, and you might have rubbing issues. With the 295´s you will have to roll rhe inner fender lips for clearence.
To be sure, I would have used 5mm spacers and 285´s, and you should be good to go!

 

Thanks for the info. That track looks familar...TWS? I'm going to try to make the May DE. I run in yellow.
Look for a midnight blue 987S #337. Thanks again!