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Old 08-29-2021, 10:51 AM   #13 (permalink)
JARblue
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Location: Austin, TX
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Quote:
Originally Posted by SteveVQ View Post
Contimplating 255/40 fronts and 305/35 rears. I like beefy sidewalls and from what I've read it will provide the most accurate speedo readings.

What would be the Pros and Cons compared to the 265/35 - 305/30 ?
That middle tire size is a ratio of the sidewall height in comparison to the tire width. So it doesn't provide the most accurate speedometer reading unless you use the exact same tire size specified by the vehicle manufacturer. Ultimately it's all about the diameter of the tire.

If you pick wider than OEM tires with the same profile ratio, then your tire diameter is larger than the OEM tire. When you start going wider, you may need to reduce that sidewall height (lower profile ratio) to bring the diameter back closer to OEM. Don't forget that you also need to keep the front and rear diameters within 3% of each other.

Here's what the tire calculator says for diameters:
OEM Nismo 245/40/19: 26.7 inches
OEM Nismo 285/35/19: 26.9 inches

255/40/19: 27 inches
255/35/19: 26 inches
265/35/19: 26.3 inches

305/35/19: 27.4 inches
305/30/19: 26.2 inches
315/30/19: 26.4 inches
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