A rant about tires
 

:mad:

I just want to bitch about tire manufacturers and tire sizes. My partner's Infiniti FX35 needs new tires. It needs them bad -- they failed inspection yesterday, so we have 15 days to get new tires on it.

The OEM tires are Goodyear Eagle RS-A 265/50R20. They suck, equally in treadwear, handling (especially on wet roads) and road noise. But there are actually very few options available -- only a handful of manufacturers make this size tire. The reason is because the Infiniti FX is the ONLY vehicle that uses this size!

We have to get all seasons, not summer tires since we live in the mountains in Virginia, and winter approaches, and we can't afford to buy snow tires & wheels AND then buy summer tires come spring.

So that limits us to about 3 choices of all-seasons available in that size.

The Goodyears are on indefinite manufacturer backorder...meaning there isn't a single tire to be had on the continent! The only option available through a local tire place (and I called them all!) is some brand I've never heard of called Hankook. I'm leery of a tire brand I've never heard of.

I finally found a set of Toyo Praxes S/T's from an online place called Tiresavings.com and ordered them.

So my first gripe is with Infiniti for using such an odd size for this vehicle that there are so few choices. My second gripe is with the manufacturers for letting the backorder situation get out of hand -- the guy at Tirerack.com told me he has 27 sets of the Goodyears backordered...in other words, there are 27 Infiniti FX owners across the country who are waiting indefinitely to get tires!

Well, I haven't heard anything bad about Hancock tires so I think you will be okay. Its an SUV not performance car so I wouldn't worry about nickpicking on tires--if you get those tires from a reputable shop such as discount tire you should be ok with warranty.

Hankook tires is a Korean brand. I have seen some of their ads on TV. In general Korean products suck for the first generation or two, then they get much better. That is a reason in looking at cars now - tire size. When I see cars at autoshows now I really do marvel at some of the new ones coming out because in looking at these oddball sizes I know it will be tough to get new tires. If it is a 16", 17", 18" usually you are OK because you can get an approximate tire (next higher tread size - i.e. 225 can go to 235 or even 245 with little problems) but once you get to 19" or 20" you really are in some custom tire territories. I don't begrudge tire companies, would you rather make 10,000 tires in 14" to 18" tires that you can sell or run a line of 19" or 20" that you will only have a limited run on. Blame Infiniti on this one. They wanted to make the tires larger/more appealing to you, but they have no way to keep up with demand. They either should have gotten an agreement with Goodyear to hold a line open for them/this tire size or contracted out with several manaufacturers to OEM the tires from.

The reason why you are getting these rare larger tire sizes is because people are asking for them. Is there really a need to have 20" rims on an SUV? Blame the rap stars :D ...if they weren't putting 22" spinners on their hummers you'd probably not have 20" rims on your SUV.

Is there really a need to have 18" rims on a sports car?

The FD seemed to do just fine with 16s.

I thought larger rims provide a smoother ride, while a lower profile provided better handling?

I thought it was for looks but I'm not complaining, if you take your 8 out to the track the serious autoxers will be running a smaller rim cause it is lighter

I also thought it was for looks, but was told smoother, more precise ride. Who knows.
The car looks, and drives great.

When my 8 was wrecked and my 16" bridgestone needed to be replaced, it took six weeks to find one. Not only are odd sizes hard to find but high performance is a tough match also. Plus, I think that you sacrifice some ride comfort by going with larger rims.

The primary driver of larger wheels is definitely aesthetics. Generally speaking, the bigger the wheel size, the lower the aspect ratio of the tire. Small aspect ratio tires require very stiff sidewalls, which give you more precise handling, but sacrifice ride comfort. So, whoever told you that larger wheel sizes result in a smoother ride is incorrect in most cases. Think of the limiting case: driving on an infinitely stiff tire, or on a bare wheel. The ride will be extremely harsh.

This brings up a another point I'd like to discuss: durability risks when upsizing from the OEM wheel/tire size. However, I'm going to do this in a new thread:
https://www.rx8club.com/series-i-wheels-tires-brakes-suspension-55/durability-risks-when-upsizing-oem-wheel-tire-size-45178/

Larger rims will make your car handle better, however, it compromises ride quality. Having less side wall make for more precise handling but a harsher ride will result because there is less give in the tire.

however, there is an optimum size for each vehicle. You reach a point when wheel size increases weight so much so that it negates any handling benefits. Typically for sports cars 17in-18in-19in are the best. Honestly--any higher than 18in is more for aesthetics.

back to your original post :) your decision to go with TOYOs was a good one, as for Hanock also not bad tires...just limited brand recognition has kept price nice and low

you could get new rims and more standard tires...sell your stock rims, that will cost more but then you can get some smaller ones that will cost less for tire replacement