Offering this post for those S197 owners using factory 18 inch wheels but considering upgrading to aftermarket wheels:
As part of a planned upgrade I moved from the 2011 GT
stock 18 inch wheel and Pirelli setup to Motegi MR127 18 lbs wheels and Nitto 555 tires. I did this at a large but independent tire shop that is a Motegi dealer and a Nitto dealer and could offer the manufacturer's catalogs.
The Motegis weigh 18 lbs. The stockers weigh 26 lbs.
The difference after the 8 lb per wheel loss is incredible.
The entire car feels noticeably lighter. The car feels like it 'rolls' more quickly and fluidly. This is noticeable (a) poking around parking lots, (b) accelerating under normal city traffic conditions between 500 and 1500 rpm, (c) executing 'lane change' acceleration paired with quick lateral steering shifts at 40 mph or so.
After the tune, which for me as an SCT/BAMA from AM, this Motegi wheel upgrade was the single most important and noticeable upgrade on the entire vehicle, in terms of driveability, performance, feel, and speed.
I am intrigued to find a way to get the car to tell me how much quicker, quicker mind you, not faster in pure HP available terms, but quicker, the car is with the lowered wheel weight.
The car has an Aero Force Interceptor plugged to the OBD2 and the Copperhead, and I usually leave it so it displays HP in use. Will it show whether the newfound lifting of the wheel weight restriction the Motegis provide over the stockers has any effect on the HP use the Copperhead measures in like-for-like driving conditions?
What does torque push against? Gravity, weight, and also restrictions. Lower the restrictions, and . . . I wonder . . .