18\ Wheels

[RedRaptor]

Been reading a lot of posts over at M3F with a lot of the members upsizing their wheels to 18\" and 19\". Its something I might want to do if I decide to get aftermarket wheels & tires next summer season.

Got a few questions. I think 18\" is a good upsize so I was wondering what tire size should one choose? 225/40/18 or 225/45/18? I know that 225/45/18 will have a small impact on the speedometer according to the Miata Tire Calculator. But do you guys think that 225/40/18 is a bit too thin on the sidewall?

Are their any other issues involved with upsizing? For example, rubbing is a possibility. Are there any other negative effects of upsizing?

EDIT: How much would a set of four 18\" tires cost usually? Price range?

[midnightfxgt]

If you upsize and go with a thinner sidewall you have a better chance of bending the rim on potholes etc. you will also have a rougher ride

~JOHN

[Dr Butcher]

+1

What John said.

Other than that, if you keep the outside diameter of the tire the same size as stock I don\'t think you should have any problems. I have 225\'s on my car and there\'s no rubbing going on. I haven\'t lowered my car though.

[RedRaptor]

Dr Butcher,

What are the specifics of your wheels & tires? Are they 17s or 18s?

I don\'t plan to lower my car even if I upsize to 18s. I find that the Mazda 3 is already low compared to say the Matrix. I actually prefer a higher ride since it makes it easier for bigger & taller guys like me to get into the car.

So would you guys recommend 225/45/18 instead?

[Dr Butcher]

I went with a 17 x 7 rim and 225/45R17 tires. I wanted the Fuzion tire but it wasn\'t made in a 205/50R17 so I had to bite the bullet and go with 225\'s and I\'m glad I did. I like the wider look they have over the stock tires. I didn\'t want to go with a bigger diameter than 17\" because I liked the stock look of the 17\" rim. Like John said if you start going too big you lose ride comfort and risk damaging the rim and tire with road hazards. Plus, IMO if you go with a bigger rim it looks kind of dumb if you don\'t lower the car. To upsize to an 18 rim you\'ll pay extra there, then you\'ll pay extra for tires, then you\'ll eventually have to pay for springs, lowering, alignment etc.

Stick with the stock 17\'s for now, they look great on your car! :)

If anything upgrade your tires next spring and see if you can sell the Goodyears.

[RedRaptor]

Originally posted by Dr Butcher

To upsize to an 18 rim you\'ll pay extra there, then you\'ll pay extra for tires, then you\'ll eventually have to pay for springs, lowering, alignment etc.


I definately don\'t want to lower my car, upsizing wheels or not. Let\'s say I went with a 225/45/18 tire on 18\" wheels.

Will my car look taller? What would change appearance-wise? Would there be a bigger gap between the tire and the car?

[Dr Butcher]

As long as you stick with the stock outside diameter on the tire the height of the car won\'t change at all.

I believe what happens is sort of an optical illusion. If the outside diameter of the tire stays the same, what\'s changing is the inside diameter of the tire. As you upsize your rims, you\'re losing sidewall. The gap between the tire and the car\'s fender will stay the same but because the sidewall is getting smaller it looks like the gap between the tire and fender gets bigger.

In the end what you want to do is try and maintain the stock outside diameter of the tire. If you don\'t, you will affect the speedometer and more than likely be adding kilometers onto your odometer that you aren\'t really putting on.

[///M]

IMO 18s don\'t look right if you don\'t lower the car - the stock 17s are already pushing it (I actually think the 16s look better on the stock suspension).

I like my car nice and low. The less wheel gap the better. ;)

[///M]

btw - my car has never experience any rubbing whatsoever, though I\'ve scraped it before going out of a plaza and in a touchless

[RedRaptor]

A lowered car definately looks really good. If I lived in LA where the seasons don\'t change as much and there is no real winter, then I would lower it. But I have seen lowered cars in the winter literally plow snow on the Toronto streets with their front bumper/skirt. Its too much hassle, a guy in BMW with a massive front skirt and lowered, had to take 10 seconds to turn into a raise ramp just so that he wouldn\'t scratch his frontend. I was turning right on the same ramp and saw his face and he had this \"uncomfortable but I want to stay cool\" look on his face. It was funny but I didn\'t laugh at him.

So like I said, I am not lowering my car regardless if I upsize or not.

I do agree that 225/40/18 will give you a harsh ride and you have be careful how you drive through the potholes in the GTA, or else the rim would get bent.

I saw a Mini with 18\"s and low pro tires. Very nice.