topolittle

Hi everyone,

I have a stock '06 with 6 speeds trans. The only things that is not stock are the break pads (ceramic) and the break oil (higher temp). I use the car on a day to day basis and I don't go on the track.

It is time to pick new summer tires for the next spring and I started looking for it.
I have some choices:
- Buy new tires and new wheels as well.
- Buy only the best possible tires for my stock wheels and spend the rest of the money elsewhere.

I have already read a lot of information about tires and wheels here and elsewhere on the net, but I'm still confuse. My biggest concert is the handling. I want to keep it as good as it is now or even improve it. I am aware about the law of physic involved when you go to bigger wheels (19" or 20"). It is well explained on this forum, so I will probably don't go for 20" wheels (Unless I do not understand correctly).

Another thing that I do not understand is the effect of a wider tire on the handling. Should I go with tires in the 245 range or I should stay with the stock 225 width ?

Any advices ?

ttame16

iTrader: (2)

Before people tell you to search in mean ways I'll suggest it, especially since I know there are threads concerning your topic.

Anyways, I had 245 40s on my previous 8 and the difference between that and 225 wasn't really all that noticeable unless I was driving it hard. But then again they were better tires too so I'm sure that had a lot to do with it.

dannobre

iTrader: (3)

I would go with some 245/40/18 tires on 9" rims...with about a 35 to 38 offset....they will fit without any fender mods...fill out the fenders nicely, and give you a bit more tire

TeamRX8

iTrader: (25)

Does this mean you're ready to sell me back those 10.5" SSR wheels?

dannobre

iTrader: (3)

Hell no...i love your castoffs They are by far my favorite wheels

GeorgeH

iTrader: (2)

This. You'll be happier with a set of Bilstein PSS9s under your car, on stock wheels, than the stock suspension riding on wider wheels & tires (forget larger diameter wheels if you are only interested in performance). Also, tire compound is more important than tire width.

On the factory (8" wide) rims, there isn't a lot to be gained by going over 225. For street tires, matching wheel & tire width is very important. Putting 245s on 8" wide rims might give a little gain, but not very much. If you just have to do this, then choose a tire with a very stiff sidewall. This will help maximize the benefit of the wider tire, and also keep turn-in crisp at reasonable pressures.

So, get the best tires you can afford, match them to the wheel width you have, and then get a good set of coilovers (and have them setup properly). This is a great combination on the RX-8. If you really want wider wheels & tires, get them after colovers - they will be a more "real" upgrade when you have coiliovers on the car.

My .02, others I'm sure will disagree.

topolittle

Thank's a lot for all the reply, it is very helpful.

If I understand correctly, wider tires on wider wheels will have more grip and about the same handling that the stock tires and wheels. One thing is still not clear for me, what append in the corners ? The tires will have more grip too ?

It sounds good, but I made a quick search on these coilovers. It cost about 1500$ without including the installation. I never drove a car with this kind of suspension. Is there any downside with this suspension ? I live in the north and there is a lot of snow in the winter season (Of course I have winter tire too!).

I will think seriously about starting with the suspension. If I plan to add a turbo in the following year (This is not decided yet and this will be another discussion), should I go for a wider tire now or the 225/45/18 on the stock wheel will be good even with a turbo ?

topolittle

After reading a lot about the PSS9, I decided to go with it.
Now, since my car will be a little bit lower than stock, should I go with 225/40/18 instead of the stock size 225/45/18 ? (I plan to keep the stock wheels).

Another concern is about the winter. Is this the kind of suspension that we should use only in the summer ? If I must changer my suspension every seasons, it is not a problem for me. I have all the required tools and good skills.

Thanks in advance for your advices

topolittle

^bump^

thermal1

iTrader: (3)

Stick with stock size tire (225/45/18) or 245/40/18. Suspension is not affected by the season - though the dirt and salt could cause them to be tougher to adjust and or rust faster than they would in a summer climate.

Tires are the only item you may want to change - summer tires are quite poor on cold/ice/snowy roads and can be dangerous in winter conditions.

GeorgeH

iTrader: (2)

^Yup. The only problem with a lower, stiffer suspension in the winter is reduced ground clearance, should you happen to drive in the snow. Overall grip level may suffer a bit as well, but it's manageable. If you are really worried about that, you can raise the car in the winter, but you'd need to pay for an alignment.

And yes, top-tier summer performance tires are nearly worthless in the snow, and can even be questionable in cold rain (such as Hankook RS3s).

topolittle

Thanks very much for the answer.

I am definitely using winter tires in winter. Pay for an aliment twice a year should be a solution since I leave in a place where is A LOT of snow in January and February.

Since the overall diameter of the 225/40/18 tires are a smaller than the original (about 2%) is that be conflicting with the DSC ?

And what if I want to spend a little more money and change the wheels size for 19 inches with similar weight, is there any advantage ?

thermal1

iTrader: (3)

No, the smaller diameter will look funny and mess with your speedo.
There is no advantage in getting 19s unless you like them better aesthetically.

GeorgeH

iTrader: (2)

Smaller tires will not affect DSC, but, as stated above it will result in your spedo over-estimating your speed (and any calculated gas mileage).

However, the car will accelerate a little faster.

The main thing I would be concerned about is rim protection - the OEM wheels are pretty soft. I bent one with the OEM 225/45s mounted by hitting a rather nasty chuckhole at freeway speeds. 225/40s would make that possibility more likely, I would think.

Agreed, no significant advantage to 19s.

For snow tires,

topolittle

I thought that having less sidewall will make the tire more rigid, and therefore better handling. Isn't that right ?
This is the only reason I would change for 19" or have a smaller tier on my stock 18" wheels.

About the tire width, as I understand, it doesn't improve the handling (even with a wider wheel), but it can have more grip. But unless I have a turbo, it is not a concern.

I have also a concern with the PSS9. I about to ordering the kit, but I am wondering about the sway bar. Since I plan to lower the car a little bit, do I have to upgrade the front and the rear sway bar to match the suspension ? I read some post that say that the car may overstreer in that case ?