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I have 2 sets of rims with the 19x12 305-30s. Issues? Not sure what you mean by asking that. I don't track my 911 its just my weekend warrior. Averaging 5-6k miles/year,and haven't ever had any issues with tire size or comfort(keeping in mind its a performance tire). I also have photos that I can post at a later date.
Are you running 18s and want to see the differences between the 2?
Last edited by Nastee_C4S; Feb 1, 2018 at 05:18 PM.
I'm running 305/30 rears on both my 997.1 C2S cars. Wife's runs GT3 wheels
Front - 19" x 8.5" with 53mm offset
Rear - 19" x 12" with 68mm offset
and the stance of her car from a wheel & tire placement to fender was just about perfect. When I ordered my custom Forgeline SC1s, I actually removed the wheels from my car and sent very specific measurements to Forgeline using a digital caliper as I waned them to maximize the concavity of the wheels but also needed to clear the larger 6 piston PCCB calipers in the front. With an 8.5" wide wheel and PCCBs there wasn't a lot they could do there, more so in the rears, but the fitment is perfect. Had to trim a little notch into the inside edges of the GT3 brake duct scoops I'm running in the rears but they're just plastic so no big deal. Wife's car is running Tikore Ti Lug Bolts and I have World Motorsports Ti Lug Nuts. My car has a stud kit installed and the rears were a little longer because of the RUF wheels with spacer that were originally installed, so I customized the normally closed end lug nuts to knock the center out to get a proper fit of the nut seat into the wheel, but still leave the shoulder of the lug not to cover the threads for aesthetics.
I tweaked the GT3 offset #s a little to get them exactly how I wanted since the Forgelines are fully custom forged and they are
Front - 19" x 8.5" et 50mm
Rear - 19" x 12" et 74mm
so the outer edges of the wheels have the Fronts 3mm further out than hers and rears 6mm further in. I came up with these #s based on how the previous 4 sets of wheels I had on this car fit, plus the measurements from the Forgeline worksheet I submitted to them, which looks like this.
I have factory 305's on my 4S and they are on 19x11 wheels. I run 20mm spacers in the rear and that should be equivalent to your 19x12 wheels. I have not issues with rubbing. My car has the factory PASM sports suspension. The sport mode is to harsh for me now. Can only use it now and then. Getting fcking old.
Last edited by Targa4sg550; Feb 3, 2018 at 12:23 PM.
I have factory 305's on my 4S and they are on 19x11 wheels. I run 20mm spacers in the rear and that should be equivalent to your 19x12 wheels. I have not issues with rubbing. My car has the factory PASM sports suspension. The sport mode is to harsh for me know. Can only use it now and then. Getting fcking old.
You would need to provide the offset of your wheel in order to be able to make any type if comparison, plus putting a 305 tire on an 11" wheel vs a 12" wheel changes the profile of the tire where yours is more rounded and tucked in and on a 12" wheel would be wider and sit flatter at the contact patch
I have factory 911 19x11 wheels and factory 305’s. Running 20mm spacers. The 305’s will stretch even more on the 19x12’s for even better clearance.
305’s on 12’s will look like those low rider wheels and tires where they run all that camber. Whats that called again. All the young kids do it these days LAMO SMH
305’s on 12’s will look like those low rider wheels and tires where they run all that camber. Whats that called again. All the young kids do it these days LAMO SMH
Actually, no and 305s are really too wide for an 11" wide rim - it rounds out the contact patch profile too much. Look up a wheel width and tire size chart and you'll see that the recommended section width for an 11" wide rim is a 285-295. You should run an 11.5" or 12" wide rim to run a 305 section width tire. This is why on Porsche's 11"wide OEM wheels they spec a 295 tire but on the GT3 with a 12" wide wheel they spec the 305 width tire.
Porsche sold me this setup as standard equipment. On 997.1 Targa 4 and Targa 4S the 305 on 19x11 is the factory standard.
Porsche is pretty good at what they do so I’m good with that setup. Just surprised I was able to add 20mm rear spacers and still have it tucked in as in my picture.
I shouldn’t even be on this tread. Convo is about 19x12 wheels. Mine are 19x11 and running the factory standard 305’s
Porsche sold me this setup as standard equipment. On 997.1 Targa 4 and Targa 4S the 305 on 19x11 is the factory standard.
Porsche is pretty good at what they do so I’m good with that setup. Just surprised I was able to add 20mm rear spacers and still have it tucked in as in my picture.
I shouldn’t even be on this tread. Convo is about 19x12 wheels. Mine are 19x11 and running the factory standard 305’s
I have the option code 404 forged "turbo" like wheels on my C2s that came with 305 as well. The person before me put the evo12 tires on them which look pretty spot-on but the tread width on those versus a PSS is almost an inch different ( IIRC around .8" difference) so that PSS is really maxed out on this rim from a performance standpoint.
IMO an 11.5" width is great for a 305. Porsche puts a 325 on the GT2 on the 12" wheel which can be spot on with a more narrow running tire and a little maxed out on wide running rubber.
The table above is nice but not quite as accurate as what the actual tire manufacturers recommend. For Michelin for example...
On their 305/30/19 they spec anywhere from a 10.5" to 11.5" rim. They do not recommend a 12" rim for their tire. Same for Hankook, Pirelli, Continental.
