Help with tire sizes?

[GTRON]

Hey guys, I don't know squat about tire/rim sizes.
I want to get some decent looking rims on my car.
I'm wondering how to get 16" rims on with thinner rubber so I'm not altering stuff like speedometer and transmission. (bear with me, I don't know what I'm talking about, though I would like too )
Also, I it wider (--)

[ExplodingCake]

http://www.miata.net/garage/tirecalc.html

This tool will help you.

[Chrisnick]

CB7's tend to want a 24" tall tire. On my CD7, the speedometer was GPS correct with a 25" tall tire(205/55/16 and 225/50/16). 205/50/16 is probably your best bet, but I've also fit a 205/55/16, 225/45/16, and 225/50/16 in addtion to the previously mentioned 205/50/16 on my CD7 with a 16x7 +45 wheel. Any four of those should work. A 195/55/16 could also work but tire choices aren't as good. What wheel size are you going to run?

In all honesty, a 17" wheel/tire makes things worlds easier for tire options. In that case, a 215/45/17 and 225/45/17 probably would work best. You could go shorter with a 215/40/17 and 225/40/17, but once again tire choices aren't as widespread.

Find out what tire size you're currently running, GPS verify speedometer accuracy, and figure out tire height from there. Width wise, 205-225 works VERY well on the street. In my experience, a 7" wide wheel likes a 205, an 8" wide likes a 225. You can easily put a 205 on a 8" wide, and a 225 on a 9" wide, but wheel choices arent as common in those widths for a 16" wheel.


TLDR; 16x7 and 205/50/16

[GTRON]

CB7's tend to want a 24" tall tire. On my CD7, the speedometer was GPS correct with a 25" tall tire(205/55/16 and 225/50/16). 205/50/16 is probably your best bet, but I've also fit a 205/55/16, 225/45/16, and 225/50/16 in addtion to the previously mentioned 205/50/16 on my CD7 with a 16x7 +45 wheel. Any four of those should work. A 195/55/16 could also work but tire choices aren't as good. What wheel size are you going to run?

In all honesty, a 17" wheel/tire makes things worlds easier for tire options. In that case, a 215/45/17 and 225/45/17 probably would work best. You could go shorter with a 215/40/17 and 225/40/17, but once again tire choices aren't as widespread.

Find out what tire size you're currently running, GPS verify speedometer accuracy, and figure out tire height from there. Width wise, 205-225 works VERY well on the street. In my experience, a 7" wide wheel likes a 205, an 8" wide likes a 225. You can easily put a 205 on a 8" wide, and a 225 on a 9" wide, but wheel choices arent as common in those widths for a 16" wheel.


TLDR; 16x7 and 205/50/16

How wide can I go without scraping anything?

My speedometer is approximately 2mph fast

[Chrisnick]

It's all dependent on offset and alignment settings. With a 16x7 +45 and the 225/45 or 225/50, I was very slightly rubbing on the inside, just enough to haze the paint/fender liner coating. I'm going to running an 18x9 with an effective +30 ish offset up front and +25 ish offset out back with a 255/35/18 at all corners. I'm going to have to roll and pull the rear hard, but that's about as wide as you can do before you have to start cutting. Try willtheyfit.com and rimsntires.com to get a decent idea of how that all works.

A 16x7 with a 30 to 40 offset would work really well with a 205/50/16.

At what speed is your speedometer 2mph fast? And what is your current tire size?

[GTRON]

It's all dependent on offset and alignment settings. With a 16x7 +45 and the 225/45 or 225/50, I was very slightly rubbing on the inside, just enough to haze the paint/fender liner coating. I'm going to running an 18x9 with an effective +30 ish offset up front and +25 ish offset out back with a 255/35/18 at all corners. I'm going to have to roll and pull the rear hard, but that's about as wide as you can do before you have to start cutting. Try willtheyfit.com and rimsntires.com to get a decent idea of how that all works.

A 16x7 with a 30 to 40 offset would work really well with a 205/50/16.

At what speed is your speedometer 2mph fast? And what is your current tire size?

Ok, I don't really understand the lingo yet, I don't know what offset is, I'm green

It's consistent 2mph off (or fast) on everything under 60mph. I haven't tested any faster than that..

If you could recommend a good general size that looks/works good on our cars. And isn't hard to find/get

[deevergote]

[deevergote]

The goal is to keep the overall wheel/tire diameter the same as stock.

Go to any reputable wheel and tire website, such as TireRack.com. Search for wheels for your car. They will only show you wheels that are an appropriate width, diameter, and offset for your car. Add tires to the package, and they will be the appropriate size. When you're running larger wheels, some tire sizes aren't 100% correct. For example, my old 17x7.5 wheels came with 205/40/17 tires... which were a little small (speedometer was optimistic.) I could also have run 205/45/17, and my speedometer would've read a little slower than I was actually going.

When it comes to tire sizes, the first number is the width of the tire. The second number is the height of the tire, properly known as the "aspect ratio". It is a function of the width... meaning a 195/45 tire will be shorter than a 215/45 tire. The third number is the diameter (that one should be obvious.)


Also, when a speedometer is off, it is off by a percentage. For example, if it's off by 5%, your speedometer will say 20mph when you're really going 19 or 21. If your speedometer says 100mph, you'll really be going 95 or 105 (depending on whether your tires are smaller or larger than the stock diameter.)



Those are the basics. I suggest you do actual research to understand wheel and tire sizing. You're not likely to get bad advice on here... but this is something you'll be better off actually understanding, rather than just buying what the internet tells you to buy.

[GTRON]

The goal is to keep the overall wheel/tire diameter the same as stock.

Go to any reputable wheel and tire website, such as TireRack.com. Search for wheels for your car. They will only show you wheels that are an appropriate width, diameter, and offset for your car. Add tires to the package, and they will be the appropriate size. When you're running larger wheels, some tire sizes aren't 100% correct. For example, my old 17x7.5 wheels came with 205/40/17 tires... which were a little small (speedometer was optimistic.) I could also have run 205/45/17, and my speedometer would've read a little slower than I was actually going.

When it comes to tire sizes, the first number is the width of the tire. The second number is the height of the tire, properly known as the "aspect ratio". It is a function of the width... meaning a 195/45 tire will be shorter than a 215/45 tire. The third number is the diameter (that one should be obvious.)


Also, when a speedometer is off, it is off by a percentage. For example, if it's off by 5%, your speedometer will say 20mph when you're really going 19 or 21. If your speedometer says 100mph, you'll really be going 95 or 105 (depending on whether your tires are smaller or larger than the stock diameter.)



Those are the basics. I suggest you do actual research to understand wheel and tire sizing. You're not likely to get bad advice on here... but this is something you'll be better off actually understanding, rather than just buying what the internet tells you to buy.

That's very informative, sounds like I should keep this thread!

[GTRON]

What would be some good websites to buy rims/tires on? Tire rack seemed kind of lame, as it wasn't pulling up 4 lug rims....

[deevergote]

What do you mean? Tire Rack has 56 different choices for the CB7 at the moment.

[GTRON]

17" Stern beasts

I want these

[sonikaccord]

Good luck finding those.
I would also check local classifieds as well. Craigslist, forums, etc.

[deevergote]

Those are long discontinued (as is that car... sold to and blown up by a moron many years ago.) Stern doesn't make those wheels anymore. They don't make 4 lug wheels anymore. In fact, they only have two models that are under 18" in diameter!

Use Google to find good wheel sites. You can usually tell a company's quality by the brands they sell. If they have nothing but cheap knockoff junk, they're probably crap. I use Enkei as a gauge. If they don't carry Enkei, I don't shop there.

If you buy new from a good seller like TireRack or DiscountTireDirect (who I hate, but they're good enough for most...) you will get wheels, "tuner" lugnuts, and hubcentric rings. If you buy used, you are going to need to buy the lugnuts and hubcentric rings yourself.

[GTRON]

Good luck finding those.
I would also check local classifieds as well. Craigslist, forums, etc.

I couldn't find anything online about those... That's the look I'm going for at least.