DHL

Just thought I would call out an issue for Porsche owners using HRE (and perhaps other aftermarket wheels) on their cars. Ran into this myself as I just mounted a set of HREs on my Macan GTS. You MUST use the bolts supplied by HRE instead of the Porsche OEM bolts. Here is why. The HRE wheels are machined for a linear taper fitment to the bolt. Porsche bolts have a spherical or curved shape that is much larger in diameter than the taper in the HRE, which means if you use Porsche OEM bolts on an HRE wheel, you are making a line contact with the edge of the hole machined in the HRE rim, as opposed to a full surface contact along the taper. The tapered bolt shape is almost universal among all other brands except for Porsche, which seems to be why HRE does not specifically mention this on their site or to Porsche customers buying their wheels. To make matters worse, the tapered bolts have a 17 mm hex and the Porsche bolts 19 mm hex. This means the wheel change wrenches in the trunk will not fit the HRE 17 mm bolts so you need to put a 17 mm wrench in with your OEM spare change hardware. You may also need to add 5 OEM Porsche bolts to your spare kit as I assume the spare wheel will not work with the 17 mm HRE tapered bolts.

I had originally thought that because I was buying custom HRE wheels made for a Porsche, that these would use the OEM Porsche bolts. Was wrong about that.

Spyder Bite

That’s literally every aftermarket wheel not just HRE. They don’t mention it because it’s pretty common knowledge.

Hal

Not true. I have put BBS wheels on previously owned 993's and 996's and the OEM bolts worked perfectly. Also put BBS's on my current '06 Cayman and again, OEM bolts were perfect.

I would suggest a prospective buyer ask the seller what style bolt is required and order a correct set if different than OEM.

Spyder Bite

BBS is an OEM supplier of wheels. Not exclusively aftermarket

VAGfan

Porsche, VW, and Audi original wheels use "ball" type wheel bolt seats. Most, if not all aftermarket use conical.

Blame your aftermarket wheel vendor for not telling you this.

DHL

Do the BBS wheels have spherical sockets? If not, probably not a good idea not to mix tapered (conical) with spherical. I used OEM conical Porsche bolts on my HREs for my 911 (not realizing the differences), and they torqued up and appeared to work fine. But I don't really know if I was damaging the tapered seats on the HRE wheels by doing so. Also, the total thread engagement with the OEM bolts on the tapered seats is less than the tapered bolt because the spherical bolts seat further out. I think there may be safety issues as well by mixing the two seating systems, especially in vehicles capable of triple digit speeds.

DHL

Well, HRE does send a complete set of the proper bolts with the wheels. What they don't make clear is the user MUST use these bolts because they machine a taper seat instead of a ball seat. When a customer orders wheels from HRE, they are told they get cusom machined wheels for that specific vehicle. All the other parameters such as offset, rim width, hub center, bolt circle etc are specific to the Porsche Macan so why not the bolt socket? Machining the wheels is done on an as ordered basis on fully computerized CNC machines, so cutting a ball socket instead of a tapered one is pretty simple.

Jeff Whitten

Since your post is intended to be informative to others that might know be aware, maybe change your post name from “HRE” to “Aftermarket wheels”.

Maybe a reflection on where you bought the wheels, not the brand. I have bought HRE and OZ Racing wheels over the years from several different good shops, that always emphasize the inclusion of and must use included lugs as they differ from stock. Good experiences include Tire Rack, Tag Motorsports and others.

Good info to share with the community. It may not be obvious to all.

DHL

I was careful to specifiy HRE because I was not sure the issue extends to all aftermarket brands like OZ or BBS. I purchased the wheels directly from the HRE factory, not a distributor. I am sure HRE will clarify this issue with Porsche customers in the future. In the past my experience was mainly with BMW, where the factory lug bolts almost always were the same as used with my aftermarket OZ, BBS, or DP wheels.