David Weiss

greetings All,

I have the itch to swap my RS Spider Center Lock Wheels, because of the wimpy offset. wider tires are nice too. apparently, the RS's have the crappy offset to accommodate snow chains in Germany? I live is Southern California!

I am stuck on the HRE P40sc, as there are few good choices for Centerlocks and they work quite well in matte black with my Riv Blue wide body.

My dilemma exists between choosing 19" or 20".

anyone have experience with this dilemma? Any 20" users/experience on a 997.2 out there?

Thanks in advance!

jhbrennan

While 20's look great you'll get a rougher ride plus I think that 20's make the rotors look too small - just personal preference.

mdrums

Your suspension is designed around 19"....want to keep the great handling?...stay with 19"


Do you have a GT3RS or a Carrera 4 or GTS? This makes a difference with front offset you can have.

Carrera based wide body with spec camber you can use:
8.5x19 et53 front and either 235 or 245/35/19 tire
12x19 et 48 rear you can use either 305 or 325/30/19 tire

IF you have a GT3RS you can use a 9x19et 47 front.

Mumbles

I beleive that you have to use the tire sensors from your original 19's and install them on your 20's if your going that route. Personally I think the 20's are gonna be a rough ride, but it all depends where you drive and your location.

hakaida702

I know that a lot of guys like HRE wheels, but I would rather go with a stronger set of Volk Racing G12 centerlocks or do the 5 lug conversion and get the G25 with a special order for porsche fitment.

MessyMarvin

I think 20" looks way to big on the 911, I would stick with 19". JMO

AlohaCS

Just put new 19" wheels on my 997.2. They look perfect. I think 20" wheels make the tires look like rubber bands and out of proportion to the car and the wheels.

gonz911

There's not much difference in the feel of the road going from a 19" to a 20". I also don't think they look out of proportion, but then it's all about personal preference.

mdrums

Hi David, this could be a real long answer especially typed out.

I have a 2012 GTS as well. I track the car a lot. I've been at this with 997 based cars since 2006.

What you have to think about is that the tires are also part of the suspension. There is a point of no return with how thin and or how tall the tire sidewall is. There has to be some flex in the tire sidewall so it can roll over some in order to keep more of the tire tread on the ground. If the tire sidewall is too thin the tire does not roll and the tire tread will pick up off the ground and not provide any tread to the surface.

This gets even more complicated but there are books on suspension basics. I have used both 19" and 18" at the track. I have done this and maintained the over all tire dimensions. What I am talking about is this....
245/40/18 front
305/35/18 rear

is the same overall tire dimension as stock
235/35/19 front
295 or 305/30/19 rear

Only difference was the tire sidewall heights. The 18" were better especially over bumps. Yes you are correct Porsche picked the 19" due to what the public wanted...marketing. They have worked the suspension very well to make 19" work with PASM. However if you take a non-PASM 997 and install 19" on it..it drives really bad. This has been documented in a few Porsche magazines as well. This is the same if you put 20" on a 997 PASM car like our GTS cars. While 20" wheels might make look good in your eyes the handling toward the limit will suffer due to trying to keep the tire at the correct overall dimension the sidewall will be very skinny.

The 991 S comes with 20" but the tire side wall is not as skinny/short as if you put 20's on your 997 car.

hope this helps some.