[MystiChrome Coupe]

If I were to go from my stock 17's to a 18 (FR500's) would I gain any ground clearance? I've got a lowered ride & wouldn't mind even a 1/2" extra space between my underside & the occasional bump that scrapes. I imagine it would also depend on the tire size, but I would go with whatever size would fit the best, look the best & have no rubbing problems.

Also, has anyone ever seen or heard anything about the FR500 replicas that are availible? I've seen some on ebay. Silver, chrome & some other finish. Been thinking about maybe trying to get a set cheap.

Here's a link to a past auction on these wheels.
http://cgi.ebay.com/ebaymotors/ws/eB...ory=43958&rd=1

[Firme]

you rim size does not matter as long as the overall diameter of the tire is the same.

If you change the overall diameter, then your speedo will be off..

[djtech]

Hey whitesnake! That's great your looking for some nice wheels! Like Firme said the wheel isn't what matters but the combination of the wheel size and the tire size. For example I have a set of AFS 03 Cobra replica's that are 18 inch versus our stock size of 17. If I wanted to keep the same diameter (aka same ride height) I would just get a lower profile (aka series) tire.

245-45/17's have an overall diameter of 25.7"
245-40/18's have an overall diameter of 25.7"

They have the same ride height and diameter because the aspect ratio is 40 versus 45. If you wanted a taller ride height you could stick w/ series 45 on your 18's (245-45/18) but you'd need to get something to adjust your speedo.

HTH!

Originally Posted by whitesnake

If I were to go from my stock 17's to a 18 (FR500's) would I gain any ground clearance? I've got a lowered ride & wouldn't mind even a 1/2" extra space between my underside & the occasional bump that scrapes. I imagine it would also depend on the tire size, but I would go with whatever size would fit the best, look the best & have no rubbing problems.

Also, has anyone ever seen or heard anything about the FR500 replicas that are availible? I've seen some on ebay. Silver, chrome & some other finish. Been thinking about maybe trying to get a set cheap.

Here's a link to a past auction on these wheels.
http://cgi.ebay.com/ebaymotors/ws/eB...ory=43958&rd=1

[MystiChrome Coupe]

Thanks for the replys.

So if I understand correct, the first # is the tread width, the second is sidewall hight, the third is rim size. Correct? Also how much of a difference is there between the 245/45/17 vs. the 245/45/18 in the example mentioned above?

[Firme]

Originally Posted by whitesnake

Thanks for the replys.

So if I understand correct, the first # is the tread width, the second is sidewall hight, the third is rim size. Correct? Also how much of a difference is there between the 245/45/17 vs. the 245/45/18 in the example mentioned above?

I have heard many different confusing theory's on how it works, but the way I "think" it is is...

example:
245/45/17
245 is the width of the tire/tread/45 is the percentage of the tread that is the sidwall - for example multiply 245 by .45 and that is how tall the sidewall is/ and 17 is the inches in rim size.

the difference between the two you asked

diameter of 245/45/17 = ~25.7"
diameter of 245/45/18 = ~26.7"
which would mean that your car would sit about .5" taller (you gain .5" below the center and .5" above) and your speedo would be off.

[99Blk4vCobraSgt]

Would bigger rims slow you down at all

[99Blk4vCobraSgt]

i raed a 01 coba with 18 cobra rs n i got a 99 with the stock svts i roasted him i might just have more mods

[Firme]

Originally Posted by 99Blk4vCobraSgt

Would bigger rims slow you down at all

well, there is a few factors. Bigger rims and same overall diameter = less sidewall. Less sidewall = stiffer ride and less "give which = harder to launch really hard and more tire spin off the line (due to sidewall not absorbing as much launch torque).

Now, at the same time, the same train of thought as above = better handling due to stiffer sidewall to reduce "squishyness" in the corners.

As far as slower.... well it really depends on the weight of the rims. You can get some high quality 18 in" rims that weigh less than the stock 17's. It boils down to rotating mass. If you have more weight to turn, its gonna take more power to turn it and slow it down...

Most people just throw the rims on and don't think about it.

Originally Posted by 99Blk4vCobraSgt

i raed a 01 coba with 18 cobra rs n i got a 99 with the stock svts i roasted him i might just have more mods

I don't think 18" Cobra R's would be a determinig factor... rather.. him being stock vs you highly modded or him not being able to drive

[lz_mystic_cobra]

Originally Posted by 99Blk4vCobraSgt

Would bigger rims slow you down at all

generally... yes. But from 17 to 18, you won't be able to tell much unless the 18's are a lot heavier...

[larrendeuce]

I always thought it was strange for the industry standard for tires to use millimeters for section width and inches for rim size. Some truck tires use inches for everything.

[larrendeuce]

slicks use standard measurements too.

[Matts01cobra]

firme's got it down. The first number is section width in mm's and the second is called aspect ratio and is expressed as a percentage of section width and obviously the last is rim diameter. Why they size tires this way I do not know for sure I used to think it was the whole ISO/9000 thing. If you do not know what this is.......nevermind the explanation would be quite long but suffice it to say it has to do with manufacturing standards any of you who work in manufacturing have at least heard about it. Anyhow it is supposed to make components manufactured by different companies one in the same. But this theory was blown recently when I realized for example that a Nitto 315 was actually narrower then a BFG 315 when mounted on the same rim? Believe me I learned this the hard way.

[shane361]

Dont want to steal your thunder whitesnake but since we are on the topic of tires...I recently got caught in the rain which is something that never happens cause rain on my car is a bad thing. I never drive it and show it mostly. I have Nitto drags on the back and the front left tire has 75% tread and the rite is ugly. Now in the heavy rain I had no control of the vehicle and almost crashed a few times. Could there be anything other than the tires causing this?-Thanks in advance-shane

[Firme]

Originally Posted by shane361

Dont want to steal your thunder whitesnake but since we are on the topic of tires...I recently got caught in the rain which is something that never happens cause rain on my car is a bad thing. I never drive it and show it mostly. I have Nitto drags on the back and the front left tire has 75% tread and the rite is ugly. Now in the heavy rain I had no control of the vehicle and almost crashed a few times. Could there be anything other than the tires causing this?-Thanks in advance-shane

KNOWN FACT = Nitto Drag Radials and RII's and absolutely HORRIBLE in the rain.. its the tires in the rain...period (now regular 555's are just like most other tires)

[COBRA90GT]

Originally Posted by Firme

KNOWN FACT = Nitto Drag Radials and RII's and absolutely HORRIBLE in the rain.. its the tires in the rain...period (now regular 555's are just like most other tires)

What he said!!