Hey, I'm sorry if there's another post about this but I have the stock front 225 45 18 and rear 245/45-18 and I want to make my rear 275/40-18.

How will this affect my traction, speed, handling, gas mileage, etc?

I'm a noob to cars I know but thanks in advance

 

All you need is a wheel wide enough to run that tire. 9 inch minimum, 9.5 inch or wider is better.

 

Read this post in the Top 100 FAQ:

Entire thread (a good place to learn more about the car)

https://my350z.com/forum/2003-2009-n...questions.html

Specific post that answers your question:

https://my350z.com/forum/4936171-post42.html

 

Yup, sizes fine. Just need wheels wide enough to accommodate the new tire sizes.