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Hi everyone,

If I want to change the stock 17" wheels to 18" wheels on my SE do I need to have anything else calibrated?
 

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Hi everyone,

If I want to change the stock 17" wheels to 18" wheels on my SE do I need to have anything else calibrated?
Not really, no, it's all in the overall wheel diameter, meaning the tire diameter. The stock 17" wheels with 215/65-17's are 28" in diameter. That being said, consider this, the 18" combo available is I think, 28.7" the 255/45-20s on the back of SRTs? 29.1" I don't think you NEED to recalibrate, but the speedo will be off a bit, probably neglegible, but it will be off a bit. Your car won't gripe and complain at you. Go with the R/T wheel/tire combo in 18". that would be the closest to the stock diamater. (tires size would be 235/55-18)
 

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Depending on specifics, you may want to get your speedo recalibrated. Below is a link that allows you to enter stock tire size and how it affects everything with an alternate size.

Tire size calculator

As noted, unless overall diameter remains identical you will be going slower/faster than what shows on the speedo. Also to some degree, I believe it will affect your odometer as tire diameter also effects revolutions per mile.

To add a little more complexity to this situation, keep in mind that not all 245/45/20 tires are going to be the same exact size. Using this size, mathematically the tire should be 28.68" tall (diameter). However, when you check with each tire manufacturer you will quickly learn that not all (if any) 245/45/20 are the exact 28.68" size. Some may be 27.5", others may be 28" or 29".

To see how the math works, go here: Tire Tech Information - Calculating Approximate Tire Dimensions

I realize comparing manufacturer sizes to mathematical sizes are being extremely picky; however, the overall diameter affects the revolutions per mile (RPM) so even if calibrated for a 245/45/20 you could be off slightly when using Brand A tire vs Brand B tire.

All this being said, I changed tires on my Nissan Titan and didn't bother with recalibrating. However, I went to the first link I provided and know how to manually adjust the speedo when I'm driving so I know my real speed.
 
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