Why is my rear tire smaller Diameter than my Front ( ? )
- 2004
- 911 Carrera
Bill, John Ellis from GGR San Carlos checking in again. I will send some images to the PCA.org address to better demonstrate my challenge/ question. Here is what's up. I used to have a 2001 Carrera with 19" Lowenhart 3 piece wheels, Rear tire size is 285-30-19 ( 25.7" diameter ). I have no clue what the offset is as I can't find much info on these nice wheels as Lowenhart is out of business. Regardless, I really like the appearence, fit and performance of these wheels ( my tires are the Conti DWS fitment ). A liitte inside rub on the fronts, but nothing extreme or damaging. This car was totalled in Mar, yet I kept these wheels.
Now I have a 2004 996 with the factor 18" hollow spoke Turbo wheel. The rear ( 18" 10J 65mm offset ) with Sumitomo HTRZ 285-30-18's just don't seem to fill out the wheel well as much as the should ? The fronts ( 225-40-18 ) seen fine. The other day, I measured with a tape and see the fronts are 1" taller than the rears ? I know the 285 -30s are wider, yet they seem to leave a lot of open space in the Wheel well. I looked at going to the 295-30- 18s that are recommended for the turbo, yet the turbo wheel is an 18 -11J albeit this tire is not acceptable ( per tirerack ) on the 10J wheels.
All this is simply aesthetic as the car handles and performs great. My question ( finallly ) is what's up with Spacers ? I've done a little reading on them and appears something between 12 -17mm helps push the tire-wheel a little further out. Is this really worth the effort ? What would a 12- 17 mm movement of my wheel-tire do to the suspension geometry the factory set the current wheel tire placement ? Or just install my Lowenhart set up ( this model were made specifially for the 996 no spacers ) and call it a day.
In summary to Spacer or not to keep the Turbo hollow spoke, if so what's the recommend least disruptive size/s ? Thanks for all you do for our club, always appreciate your subject matter expertise and insights. Cheers, John Ellis ( john_ellis@hermanmiller.com )