How wide tires affect overall performance

osbornsm

Generally Speaking OP:

TOO wide front tire = More Understeer
TOO wide rear = no such thing

*Note: There is such thing as having a tire too wide for the wheel also

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Chuck33079

Sure there is. It's a tradeoff between width and tire weight and rolling resistance. And your front/rear explanation just describes putting a wider tire on one end of the car. If you go wider on both front and rear in the same amount, there will be very little change in the car's balance between understeer and oversteer.

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

osbornsm

And now i learned something

Innnnnteresting...

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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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GTM TT, OS Giken GT clutch, Greddy Ti-C, Z1 test pipes, Hawk HP+ pads, steel braided brake lines, ZSpeed CSC, 34r oil cooler, CSF radiator, HKS EVC 6 boost controller, Whiteline sways, Swift Springs, Kinetix adj camber package, Osiris UPrev tune

/Angelo350Z/

The bigger the difference in front and rear tire widths, the more the car will understeer. Car manufacturers started using staggered tire sizes on sports cars mainly for safety reasons. Of course, there's also the extra grip advantage.

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2013 MB NISSAN 370Z SPORT

Jordo!

Wouldn't an overly wide front increase oversteer?

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Enjoy it. Destroy it.

Chuck33079

Yes, too wide on either end will make the other end grip less respectively. Too wide in back, understeer. Too wide in front, oversteer.

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent