tyre and rim sizes

[randymx5]

Ok does any one know or point me towards a chart which comapares rim diameter in inches with actual tyre widths in what ever they are measured in.....(is this a blond question?)

OK what size(s) can i put onto a 7.5 inch rim?? 205-215??

Regards Randall (or prob better call me Rachael from now on!)

[Dubly]

205's or 215's on a 7.5 is no problem. You could go with 225's but your sidewall profile will be far from ideal.

[irwin83r]

i run 225/50R15s on 7"wide rims.

dont do it

[irwin83r]

a site worth a look at would be http://www.1010tires.com/tech.asp

explains alot and it will even do a search and show you what tyres are available in the size your after.


warning HUGE rant coming

okay sticking with what your asking

1" = 25.4mm

7.5" = 190.5

BUT!

look at it this way the standard wheel width on my car was 6" and it ran 195s with very little tyre bludge.

the way i seen it (untill recently) was well if i increase the rim width by 25.4mm i should be able to increase the tyre width by the same amount.

so with that in mind i bought 225mm wide tyres for my new 7" rims, thats an increase of 30mm, i wanted a bit more bludge to stop gutter rash(worked a treat) and wanted the wheels to look PHAT (also worked a trear). however with the extra buldge the car feels less stable on corner turn in as there is alot of tyre roll and since i had them on 15" rim i had to go 225/50s which meant a larger running diameter, making the speedo read 5% out, the diff ratio drop, and the tyres to scrap on major pumps or road surface undulations.

so to cut to the chase because i could write a two page essay on this.

what size rim is it. diameter and width

what are you looking for.... -style? (if so what type, drifto, drag, racey)
-performance?

what are you willing to spend on tyres?

the site i mentioned should help you with the difinitions and mechanics of it all, if theres something your still not sure of just ask, ill tell you what i know and theres others on here that know a hell of alot more..

if i were you, and those were 15" rims i would be gettin 215/50R15s but that leaves you with one tyre choice thats a road legal club race tyre.

if i were not looking for a performance tyre i would go 205/50R15s that leaves you with alot of choices AND there wouldnt be that much of a difference in performance (what the 215s gained in width it may loose in side wall buldge MAY)

if i was looking for some thing that looks PHAT i would go 225/45R15 (not 225/50R15 as i did) though that leaves you with about one tyre choice also which is also a road legal track tyre.

if they are 16" diameter rims. well thats a whole other ball game...

[mxrx]

There used to be an Australian Standard about what tyres could be fitted to what rim widths. However I think that it has been rendered obsolete by the explosion in offerings of tyre profile and width.

I think that you have go by the recommendations of the tyre makers, they set the parameters of the tyre so they know what size rim it best works on.

[Dubly]

This should help you with your size questiones: http://www.miata.net/garage/tirecalc.html