My 8 currently has 235/40/18 and 265/35/18 (front tire size is 18x8 55JJ while the rear might possibly be 18x9's or 18x10's I'm not exactly sure as I never removed that tire to check) and I'm currently in need of new rubbers. With the sizes that I have currently, prices are expensive. If I were to stick to stock sizes, it would be cheaper.

I want to try getting them at a retailer like Sams Or Costco where not only they have warranties but records of where they are in the lifespan (as opposed to a random tire shop in the ghetto). Only problem is, a lot of these retailers only install tires that are the factory sizes. So, is downgrading from the large wide sets that I have, to what the factory put on them, will I be losing much in terms of handling?

My car gets driven occasionally, and while I wouldn't consider her my daily driver, she does get about 1000 miles every month. Sometimes a few hundred less.

So is downgrading worth it or should I stick the sizes I have? I personally feel the car responds and handles very well.

 

I don't think is downgrading when you go back to stock size, your just losing a wider tire...

 

This car responds and handles well with the stock tires, which are 225/45-18. If your wheels are wider than stock, I don't know how that will play into handling with stock size. Hopefully someone in this forum who knows (Monchie and I aren't experts) will chime in.

I never encountered a place that would only install stock size tires. Other than the local Mazda dealer, who only carries the OEM tires.

Ken

 

You should try actual tire shops instead of places like you are shopping at now. You would be impressed with the prices and selection. Additionally, remember tires are for more than just performance, they are for your own safety as well. While there is nothing wrong with trying to work on a budget, expect to pay a little more for a quality product that was designed to actually keep you on the road.

To add to my original post; A good dedicated tire shop also has warranty on the NEW tires that they sell based on that tire manufacturers warranty policy for whichever model of tire you are looking at. They will also look at the size wheels you have and install the proper tire size for your wheel width.

 

a 225 tire will be a little stretched on an 8.5" rim and crazy, stupid stretched on a 10" rim. if you're going back to 225's, you'll need different rims as well... don't cheap out on tires, they're the only part of your car that actually touches the road.

 

The only time a wider rear tire is needed (other than for looks) is with a high performance boosted engine. Otherwise safety, performance and fuel mileage will suffer. You also won't be able to rotate your tires so the life of a set of tires will also be reduced.
Other than the oem size, I have only used 245/40x18 tires. This was back when I was running on the track. I won't be doing that anymore, so I will be going back to oem size.

 

Why go back to 225/45? 245/40 has been cheaper every time I looked (been a while though)

 

They still are. Bought 245/40 a month or 2 ago. Cheaper or comparable to a 225/45, more contact area, and look better imo

 

I would suggest going with 245/40R18, especially if you have aftermarket wheels that are wideer than stock and you don't want to get new wheels. Take a look at the rear of the wheels and get back to us on the width of them. Then we can provide better suggestions as to what tire options are best. Another option is to see if anyone local is interested in trading for your wheels. Lots of people like the staggered wheel setup, and would be willing to trade the stock wheels for your aftermarket wheels. A square wheel/tire setup is optimal for the RX-8, and a staggered setup has no benefit unless you are boosted an pushing 250+rwhp

 

Thanks for clarifying...

 

^ This. Not to mention any place that isn't somebody's back yard keeps records of what they have done.

 

Somewhat related, I remember reading a Grassroots Motorsports article where they asked the question of what tire size was best on their RX-8 with OEM wheels for some racing series they were running in (that apparently required OEM size wheels, I think). They had assumed that the widest rubber they could get on the OEM wheels would be best. They had been using 285mm. They did timed tests on the track to find what size gave them the best track times. I believe the width they came away with was 265mm as the best width on the OEM wheels. I was stunned to read that you fit 285mm tires on the stock 8" wheels.