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Tire Sizing

Stock Tire:

/ R =
Tire Diameter: "
Sidewall Height "
Tread Width "
Tire RPM @ 60mph:

New Tire:

/ R =
Tire Diameter: "
Sidewall Height: "
Tread Width: "
Tire RPM @ 60mph:

Difference Ratio: %
Speedo Error @ 60mph: mph

When you put different sized tires on your DSM, be prepared for some differences! Lower profile, stiffer sidewall tires with a more grippy compound can be one of the biggest changes you make to your car's handling -- and ride.

Optimally, you should try to keep the diameter of your new tires near that of your old ones, so that the speedometer remains correctly calibrated. However, erring about 5% on either side of the new tire's height will cause you no problems whatsoever. Any more than that, and you'll start to notice discrepancies in your speeds.

On AWD cars, you must have identical diameter tires front and rear.

Fitment Odds 'n Ends

  • 1g DSM's can fit 225/50R16 rubber easily on a 7-7.5" wheel.
  • For those wanting more rubber, On an 8.5" wheel, 245/45 will fit (i.e. Kosei K1). You may have to grind the rear trailing arms just a hair with this +37 wheel.
  • You need to keep around >= 150mm of backspacing before there will be problems with rubbing, in general
  • Mustangs share our bolt pattern, so there are many 17x9 wheels available with appropriate offsets (+28 is common) if you wish to run 255 or wider tires (these will stick out past the fender)
  • 2g's can run 245's without problems.
  • Some folks are using 255-275 on competitively raced 2g's, but again, this requires special clearance considerations.