I need some help with determining tire combinations. What size tires are people running on a 991 with 19" wheels?
I am driving a 2012 991 Carrera S and have purchased in the past a set of 19" inch wheels from Tirerack for the track. The only modification has been a set of HHR lowering springs which has lowered the car about an inch. The tire sizes TR suggested were 235/40-19 front 285/35-19 rear. Have used Continental Sport and had great wear for multiple track events and RE71R which had insane grip although not as durable. I am interested in buying a new set of tires, looking at other options and would like to have something wider with a larger footprint. What other tire size combinations am I able to use on the 991. My concern is will different size combinations upset the car and cause an issue with traction control? Is there a rotation ratio between front and rear that needs to be kept?
Confused but eager to learn...

 

There are multiple threads on this topic. Use search or do a Google search. I'm far from an expert but in the process of putting a Tire Rack 18" wheel and tire package on my recently acquired 2013 BS to be used on the track replacing the OEM 20s. I've used Michelin Sport and PS4S in the past. Way too much of a premium on 20s vs 18s I expect to get my money back in a few years with the 18" wheels.. As I understand it you need to maintain the OEM diameter ratio between the front and rear. https://tiresize.com/conversion-chart/ is a good source. At some point the tires will be too wide or require a lot of camber to fit. I initially ordered 2020 Hankook R-S4S but my son saw the Tire Rack 2017 close out on Hankook R-S4s and I saved almost $450 for the set of four. I think your sizes are gone. See my post in wheels and tires

 

thanks for the info.