LehmanZ06

I currently run A6's for autox.

10 GT3, with front RS wheel. Car is stock height with struts rotated and shims added. -2.6 front.

Running 235/19 front, 305/19 rear.

Can I fit the 265 on the front ?

Thanks,

Lehman

Larry Cable

CarerraGT will know the answer to this...

997gt3north

It has been posted by NJGT that, believe it or not, the 235 and 265 are the same width tire in the 19s - the 265 being a taller tire, but width the same.

If you search his posts on this topic, info should come up.

Since you have the 235 in front of you, you can measure it, but the R6 and A6 have the same specs on Tirerack, and if you look at them, you will see that the section width and tread width, in their own specs, shows the 265 to be only .2 of an inch wider than the 235 but it is 1/2 an inch taller of a tire.

I don't see any benefit aero wise or fitment wise, assuming it is either the same as NJGT said, or a tiny tiny bit wider to risk rubbing because it is taller or ABS issues because it is taller.

I have the 235 R6 in my garage, just measured it, and it is indeed 10 1/4 inches in Section width - ie, it is a very wide 235 tire - ie it is really a 255.

NJ-GT

Yes, they fit. Same width as 235, just taller. Definitely a little more grip than 235 but not significant. I ran 265/345 A6 on my 997 GT3 RS with 9"/12" x19" wheels.

CRex

235/19 R6s rub a little bit on mine at full lock. I have rotated strut tops and run -2.5 degrees of camber in the front.

Carrera GT

The 265 section fits for Sport Cup and Hoosier R6 and A6. I've had it under 997.1 GT3 and 997.2 GT3 RS.

You will experience some scraping of the inside shoulder of the tire against the car at full lock -- just barely enough to leave a tire mark on the paint and since this is avoidable (I never need to make three point turns and when I'm maneuvering, I just back off the steering a tiny bit to stop the scraping.)

There's so many ways to move the wheel around on the front, I can't predict all alignment settings. I've had the 265's on both car with stock alignment and -2.2 degrees negative front camber. I'm in the process of rotating the hats and dialing in -3.1 degrees front, which will involve making sure to keep the caster about the same (there's a second lower position on the wheel carrier to compensate for rotating the hat, which I presume others already use.)

According to Hooteronline,
http://www.hoosiertire.com/specrr.ht...CAR DOT RADIAL
the 265 is a tad wider than the 235.

Item
Number__Tire Size__Tread Pattern__Tread Width__Approx. Dia__Circ____Recom. Rim__Measured Rim__Section Width
A6 AutoCross
R6 Road Race
46915_P235/35ZR19 E_______________9.25"________25.6"________80.5"___8.0-9.5"____9.0"________10.2"
46925_P265/35ZR19 E_______________9.6"_________26.2"________82.25"__9-10"______9.0"________10.4"

9.25 vs 9.6 inch tread width
10.2 vs 10.4 section switch

235 to 265 is 12.77% more nominal section width.
9.25" to 9.6 is 3.78% more actual tread width. I think 4% is close enough to call it the same, but given the option to shoehorn another 4% of tread into the front, it's fine by me.
25.6 to 26.2 is 2.34% more approximate diameter. This is not ideal. If I was having any ABS, SC/TC/PSM issues, I'd consider issues with front rear ratio and having the front as close to the factory Pirelli and Michelin diameters/circumferences. I don't have any issues with the safeties (including no ice pedal perhaps due to some brake mods)
80.5 to 82.25 is 2.17% more overall diameter. Again, pretty trivial in the context of comparing the discrepancy between the various N-rated Pirelli and Michelin factory issued rubber.
10.4 to 10.2 is 1.98% more section width.

Funny how a claimed (nominal) 12.77% section width increase arrives as a trivial 2% to 4% gain (depending upon what you care to measure) in actual rubber.

I really like the feel of the 265 R6's up front on the 3.8 RS. Ample for my purposes. Probably overkill to pay for the 4% gain, but this is a game of diminishing returns and paying premiums for marginal gains.

LehmanZ06

Rad,

I know what you said, about the 235 and 265 being equal..........just thinking that the 265 must be fractionally bigger, and was wondering if anyone else had any experience.

Seems sometimes crazy autox'ers fit wackier stuff than road racers

utkinpol

I never AXed on 19" rims, on 18" rims I used 265/335 rubber and it had substantially more grip than 245/305, on 9"/12" 18" rims. with -3 camber 265 tire outer edge was in line with fender but dives in fine. it rubs just a bit when you turn steering wheel to the limit, but in regular driving it was fine.
I think you will like 265 better than 235.