Widest tires on stick 2015 RT road and track wheels?

On a stock 8” wide wheel. 255/40-20 but with that set up you lose .7” in the height of the tire. You could go 255/45-20 which will add .3” in height and don’t know if that will hit the upper control arm bolt since 245/45-20 is close to begin with. And tire places might not too crazy with wider tires because of safety reasons.

255/45R20 will fit nicely on an 8 inch wheel. I had this set up on my 18 R/T.. they are .4 taller than 245's and will slow your speedometer down by 1 mph. check out different brands as some have wider tread width than others. Continental DSW 06 was the widest I've found at 9.1 inches.

I also have a 2015 R/T I am running 275/40R20, speedometer is off by 3mph at 75.