How wide tires affect overall performance

FortuneLSX-TT

As Chuck pointed out it is not as simple as all that. For example, for the stock Nismo sizes at 245 front and 285 rear there is a 40mm stagger. This results in the car driving like a plow under certain conditions (understeer). If you keep the rear the same size and put a wider front tire compared to stock on the front, it will not increase understeer. It will actually bring the car closer to neutral and reduce understeer. The larger front tire creates more grip allowing the car to turn instead of going straight while you're turning.

Conversely, if you simply increased the rear size and left the front alone you would be increasing understeer.

Personally, I went to a 285 front and 305 rear combination. I still have mild understeer that can easily switch to power oversteer. I do plan on going to a 305 square setup to get to neutral and so I can rotate my tires.

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