19" Wheel question

Would these 19" wheels fit my 996 TT with an x73 suspension: 19" Carrera Sport Wheels . The fronts are 8.5" and the rears are 11.5" width. The tire size is 305/30/ZR19. The offset is ET 55 front and ET 67 rear. They are for sale in the classified section and I just don't know enough about this stuff to know whether they would fit my car without any problems. (Not for track use). Thanks. GBG

Comparing the offset of these wheels to stock offsets results in: Front = 16mm less clearance inside & retract from outside 4mm Rear = 23mm less clearance inside & retract from outside 11mm You can determine this yourself here: http://www.1010tires.com/WheelOffsetCalculator.asp The stock turbo twist wheels are 8.0 et45 & 11 et50. I have X73 as well and can confirm that going 6mm out (towards fender), both front and rear, from stock offset is fine clearance wise with 19's. While I still have some fender clearance I'm not sure I would go any further than 6mm. Having said that, with the above calculations you'll clearly need some spacers to gain inner clearance. The question now becomes how much inside clearance front stock offset you have to work with. I know there is inside clearance room and I can't tell you for sure how much as I did not measure. So using this "stay within the 6mm" out from stock guideline, let's apply spacer scenarios. Using a 17mm spacer in the rear (new effective offset is 50) pushes the wheel out 6mm and you'll need 6mm of inside clearance. Using a 10mm spacer in the front (new effective offset of 45) pushes the wheel out 6mm and you'll need 6mm of inside clearance. Like I said, this being a scenario, I know you can get a 17mm spacer and I've not seen a 10mm space for our cars. While I said I did not measure inside clearance, I eye-balled it and there is plenty of room in the rear with the front having much less. So is there 6mm to be had in the front? Probably, but I can't say for certain. You also need to consider you need 6mm not just at the center on the wheel to clear the strut, but as the wheel turns. You may and up rubbing fender lining at full turn. All of this is based of course on just doing the math on the wheel offsets and does not consider tire width variables. Also, you can't run the 305/30 in the rear and stay within the front to rear tire diameter range needed by the AWD system. In other words, the front and rear tires should be a close as possible in diameter, with the proper sizes being 315/25 and 235/35. I know none of this gave you a definitive answer and hopefully it helped you understand what's involved. If it were me, I would think you'll be fine. You should also call Wheel Enhancement to see what they have to say. I'm sure they've been asked about this combo and can tell you for sure. Good luck...