Im currently running 19x9s in the front and 19x10s in the rear and the current tire setup is 245/35 and 275/30 on an 04 coupe. I have to replace these tires and I wanted to put more meat on the rear to give it more protection (there are big potholes everywhere). Would 275/40 be too much? Would it throw off my vdc or anything?

 

255/35-19 front and 285/35-19 rear give you the proper overall diameter.

You should not be at 275/30-19 rear by any means.

You can go 245/35-19 front and 275/35-19 rear. A 40 series would be too tall and would probably rub.

 

Question:

The stock 19s are

19x8 225/40/19 (front)
19.x8.5 245/40/19 (rear)

so how come if you're running 19x9, or 19x10, you can't use 40 profile? Is it because the tires are too wide and you'll rub? How come most people running 19x9 or 10 use 35 profile tires?


I'm also worried about pothole protection...

 

The reason 35 series tires are used is because the tires are wider. The "40" refers to a percentage of the width of the tire, so if you go 225->245, and you use a 40 series tire, then your new tire will be 16mm taller than stock. A "35" series tire acounts for that by decreasing the percentage of width the sidewall height of the tire is.

 

gotcha, so you're saying that 19x8 225/40/19 will have the same side wall height as 19x10 275/35/19?

thanks, i'm learning new stuff err day!

 

no, a 225/40/19 has ~ the same sidewall height as a 245/35/19, a 245/35/19 has ~ the same sidewall height as a 275/35/19. Using a tire size calculator such as this one http://www.miata.net/garage/tirecalc.html will help you match up tire sizes to stock sizes