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Discussion Starter · #1 · (Edited)
Anyone have recommendations for a a set of 18 inch wheels for 981? I used tire rack and they basically only list a set of OZ Alleggerita wheels (17.5lb). I am having a hard time finding anything online. Worse yet, I see brands, but no dealers...
 

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The O.Z.s are a good choice for 18in track wheels.
 

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Anyone have recommendations for a a set of 18 inch wheels for 981? I used tire rack and they basically only list a set of OZ Alleggerita wheels (17.5oz). I am having a hard time finding anything online. Worse yet, I see brands, but no dealers...
Wow, if you can find them that light I wonder ow strong they are. :hilarious:


On a second note; wheels have been discussed ad nauseum on here. Please search.
 

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Are you saying you don't like the OZ wheels, or that you want something even lighter? I thought 17 lb was pretty light...
 

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Discussion Starter · #5 ·
There are some wheel threads, but seems 19 or 20 inch is the focus. The oz wheels look okay, but is like to have other options. Anyone know if the OZ brand consider high quality or cheap from their experience?
 

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Discussion Starter · #6 ·
Seems like a wash actually...

With 18 inch OZ wheels, 18 lb for wheel and 25 lb for tire is about 43 lb per front wheel (+ 7lb for rears)

With 20 inch Carrera s wheels, 21 lb for wheel and 22 lb for tire is about 43 lb per front wheel (+7 for rear)
 

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Depends on your objectives for a set of non oem wheels. The OZ wheels you mentioned are popular for HPDE track events. Many go to 18s for tire selection and slightly lower price in 18 than 19 or 20. Also the OZs are cheaper than Porsche wheels. I wanted to save my nice 19in spyder wheels so a set of OZs made sense for track duty. Lighter is generally better, but I'm not a good enough driver to notice small weight difference. I have about 60+ track days on my OZs and no problems. Lots of scratches and nicks but no cracks. Have not heard of any failures on track. That said all aluminum wheels are susceptible to fatigue failure.
 

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Seems like a wash actually...

With 18 inch OZ wheels, 18 lb for wheel and 25 lb for tire is about 43 lb per front wheel (+ 7lb for rears)

With 20 inch Carrera s wheels, 21 lb for wheel and 22 lb for tire is about 43 lb per front wheel (+7 for rear)
Hi Minthral,
I'm interested in how your search goes as I am looking to do something similar.

About the wheel/tire weights, I'm not smart enough to explain why, but the 18in combination will have less weight towards the outer edge of the rotational mass than the 20in combination, which will result in less energy needed to rotate the wheel = faster acceleration and easier braking. Granted the difference may be small.

I state this based on a test I saw on tv of an Acura Intergra a few years ago. The shop had both a set of (I think) 15in and 17in tire/wheel combinations. Both sets weighted approximately the same. When the tested the car in a dyno, the 17in set registered a loss of 7 horsepower over the stock 15in set.

The commenter stated the weight of the 17in set was more towards the outside of the center of the wheel, resulting in a greater flywheel effect.

Hope this helps.
 

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Seems like a wash actually...

With 18 inch OZ wheels, 18 lb for wheel and 25 lb for tire is about 43 lb per front wheel (+ 7lb for rears)

With 20 inch Carrera s wheels, 21 lb for wheel and 22 lb for tire is about 43 lb per front wheel (+7 for rear)
235s- x18 vs x20 tiresizes TireRack Michelin SuperSport.JPG

From TireRack's published spec sheet for the Michelin Pilot SuperSport,

235/45 x18 @23 lbs w/diameter of 26.3" @ $234
235/35 x20 @22 lbs w/diameter of 26.5" @ $315

similar observations, numbers would probably apply to 265/45, 40 or 35 section height by x18, 19 & 20" diameter tire & wheel choices.

As for the location & effect of "rotating mass" - look at the "barrel" section of the wheels, 18" vs 20", the diameter of each based on an 18" vs. 20" wheel/rim diameter and the location of that "mass" in the barrel from the center point (axis) of rotation. As for the difference in "rubber" mass, the tread (outer most rotating portion of the wheel assembly) is likely to be pretty much the same, the extra 1lbs in the 18" tire is probably in the extra 2" of sidewall it has, and usually more than canceled out by the additional material, and it's location in a 20" metal rim. . . . I guess I should say IMO only, because I've seen folks get pretty heated up over this.

& Yes, again IMO, sensitive (& even not so sensitive folks when they know what they are looking for) can often notice a difference when listening/feeling/tuning into things carefully during, or while attempting high performance, i.e. tracking the car, applications. :)
 
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I'm not smart enough to explain why, but the 18in combination will have less weight towards the outer edge of the rotational mass than the 20in combination, which will result in less energy needed to rotate the wheel = faster acceleration and easier braking. Granted the difference may be small.
That almost sounds like a discussion of polar moment of inertia (of interest to all of us mid-engine drivers) where mass further out from the center of rotation has a disproportionate impact. Interesting.
 

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There are some wheel threads, but seems 19 or 20 inch is the focus. The oz wheels look okay, but is like to have other options. Anyone know if the OZ brand consider high quality or cheap from their experience?
Unlike most brands that charge $$$$ without any proven track record, OZ only supply wheels to F1 and most of the other racing series... :)

 

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The wheel you mention is used in the Tudor (Grand Am) Racing Series. They are a very high quality European MFG. The wheels they produce are German TUV approved and will meet or exceed the OE wheels strength and durability.
If I can help let me know.
 
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