I am a new owner 2008 g35x, and have been wandering the site for about a yr, My car has OEM goodyear rsa 225/55/17, and they suck, my trade-in car had 235/50/17 khumos which are nearly brand new and rode very nice on my lincoln LS, i was wondering if i can swap the tires without the computer or transmission issues, i called the service tech at the dealership and he said 50/50 shot that it would work with irritating the cpu, but they are going to charge me to just try it, and charge again to take them off if it doesent work.

Anyone ever try this, or something like it? thanks in advance!

 

The differnece in overall diameter between the 2 tires sizes is 1.864 so it will not work well. this will cause your odometer to be off by that much.

Use the link below to help you figure out what tire sizes will work. The rule of thumb is for the difference in overall diameter to be less than 1%.

http://www.1010tires.com/tiresizecalculator.asp

 

thanks for your input, the tire calculator says that you need to stay within 3%, and this tire swap fits with a bit under 2% of difference? what am i doing wrong here.

 

Stock Tire - 225/55R17 >Search Tires Tire 1 - 225/55R17 >Search Tires Tire 2 - 235/50R17 >Search Tires Tire 3 - 225/50R17 >Search Tires
Section Width: 8.85 in 225 mm
Section Width: 8.85 in 225 mm
Section Width: 9.25 in 235 mm Section Width: 8.85 in 225 mm

Rim Diameter: 17 in 431.8 mm
Rim Diameter: 17 in 431.8 mm
Rim Diameter: 17 in 431.8 mm
Rim Diameter: 17 in 431.8 mm

Rim Width Range: 6 - 8 in
Rim Width Range: 6 - 8 in
Rim Width Range: 6.5 - 8.5 in
Rim Width Range: 6 - 8 in

Overall Diameter: 26.74 in 679.19 mm
Overall Diameter: 26.74 in 679.19 mm
Overall Diameter: 26.25 in 666.75 mm Overall Diameter: 25.85 in 656.59 mm

Sidewall Height: 4.87 in 123.69 mm
Sidewall Height: 4.87 in 123.69 mm
Sidewall Height: 4.62 in 117.34 mm
Sidewall Height: 4.42 in 112.26 mm

Radius: 13.37 in 339.59 mm
Radius: 13.37 in 339.59 mm
Radius: 13.12 in 333.24 mm
Radius: 12.92 in 328.16 mm

Circumference: 84.00 in 2133.6 mm
Circumference: 84.00 in 2133.6 mm
Circumference: 82.46 in 2094.4 mm
Circumference: 81.21 in 2062.7 mm

Revs per Mile: 777.8
Revs per Mile: 777.8
Revs per Mile: 792.3
Revs per Mile: 804.6

Actual Speed: 60 mph 100 km/h
Speedometer1: mph km/h
Speedometer1: 61.1 mph 101. km/h
Speedometer1: 62.0 mph 103. km/h

Speedometer Difference: - Speedometer Difference: 0% Speedometer Difference: 1.864% too fast Speedometer Difference: 3.445% too fast
Diameter Difference: - Diameter Difference: 0% Diameter Difference: 1.84% Diameter Difference: 3.3


Tire Calculator Notes:
Tire diameter can vary slightly for each tire model. The listed diameters are from calculations based on the tire size.
When changing tire sizes, we recommend staying within 3% of the diameter/height of the original tire. Any more than this and you face the risk of brake failure. This tire calculator is for information purposes only and we do not guarantee fitment based on this calculator alone.
For more Tire & Wheel Tech Info check out the following pages: Tire Tech & Wheel Tech

Note: bold values are stock size, underlined values are 235/50/17s

 

those tires will be fine, you have nothing to worry about.
disregard nghiars bad info.

 

just an update, tire swap was fine, no computer meltdowns and much better ride than those crappy goodyear rsa's