forgive my ignorance guys but i have a question regarding tire sizing. so here it goes, basically i need to replace my OEM rear tires (yes, the OEM rears have lasted 5 years) =)

i'm thinking about getting fatter tires, so instead of the OEM size 235/50/17 i want to go to 245/50/17. will that size work on the stock 17 rims?

now the 2nd question is, since i'm not ready to purchase rims yet, but when i do get rims, will i be able to put the new rear tires (245/50/17) to the front and just get a pair of new rears when i get the rims?

i was thinking about 17" 8.5 fronts and 17" 9.5 rears. staggered setup.

much thanks in advance.

 

Tire questions are easy. What width? Same as recommended for the NISMO wheels.

 

The 245-50 will work on a 8.5" wide wheel. The problem is that as you go wider in a tire you also go taller.

Your car came with a 225-50-17 (25.85" tall)on the front and a 235-50-17 (26.25" tall) on the rear.

Basicly the 235-50 is 10mm wider then the 225-50, plus .45 of an inch taller. A 245-50 is 10mm wider and .39" taller then a 235-50.

Putting the 245-50 on the back is not a problem, aside from taking a little gear ratio out of the car. The problem is going to use that 245-50 on the front. The height is a full .79" taller. The car would start to look a little truckish. Not to mention begin to throw off the roll centers of the intended geometry of the car.

Based on your future plans for wheels. I would put a 245-45-17(25.68" tall) on the rear for now, with plans on using that on the front with the 17x8.5. This size is usable on the rear, certainly for the short term and within range (.17") of the factory overall diameter. The tire size to use on the back would be a 285-40-17 (26" tall). These sizes are each a within .17 to .25 of the respect factory heights, front and rear. This will also maintain the geometry of the car and look like it was an upgrade from the factory.

 

i was never good in math =P

but i imagined the specs of 235/50 (25.85") and 245/50 (26.25") would have the same height? because they both at 50s.

how does the 245/50 make the car higher than the 235/50? i'm confused. sorry

 

Basically you gain a little height regardless of the profile number as you get wider.

Check this site out: http://www.miata.net/garage/tirecalc.html

It helped me understand things quite a bit better. Just play with some tire sizes vs. your stock size.

 

wow..interesting!! i still find it weird how the same 50 spec'ed tire would give you +/- height with the different tire widths. but i'll take your word for it