What size tyres should i get with these wheels?

[charliebrown]

Atm i'm on 14x5.5 steelies and am considering going for slipstreams 15x6.5 +40.

My question is... what do i ask the tyre shops to fit? I'm keeping it legal so 205 would be max, and overall diameter has to be within 15mm of my current ones. Legal choices would be either:
- 205/50/15 146mm ground clearance
- 195/55/15 151mm ground clearance
- 195/50/15 142mm ground clearance

Currently on 148mm

Thanks for any help

[markismaximus]

what size tyres does your tyre sticker say should be fitted to the vehicle?

[markismaximus]

you can then use this tool which tells you the differences between different tyre and wheels sizes

http://www.1010tires.com/tiresizecalculator.asp

[charliebrown]

The sticker on my door says 14x5.5 195/60/14 86H

I've been using this website, it's the same as yours i think; http://www.miata.net/garage/tirecalc.html

[markismaximus]

also not sure how you are calculating those ride heights but they are wrong. there won't be that much variation between those tyres

[charliebrown]

Ahh i'm just using the radius lol. I'm using the distance from the bottom of my lip to the ground. At the moment it's on 148mm, so i figured if the radius of the wheel+tyre changed by 18mm, the lip to ground would be 148-18mm? Thats wrong? :(

[markismaximus]

I would get a 205/50/15 tyre to stay as close as possible to factory diameter. You would need to confirm with the tyre place that you can safely fit a 205mm wide tyre to a 6.5" rim

[markismaximus]

overall diameter = (rim diameter in inches x 25.4) + (tyre width x ratio as a percentage x 2)

example = (15"x25.4) + (205 x .5 x 2)

= 381mm + 205mm
= 586mm

[charliebrown]

Is there anyway to calculate how much lower my car would be to the ground if i got 195/50/15s? My calculations must be wrong if those would take my car nearly 7cm lower lol

[markismaximus]

the car would sit 7MM lower, not cm

[charliebrown]

*bangs head* no shit! hahah edited my first post. thanks man. main issue would be speedo going inaccurate yeah? hence factory diameter stay close as possible thing

[markismaximus]

yep. thats why I said use the above calculator. it tells you what the speed difference will be for different tyre sizes in comparison to your stock wheel/tyre combo

[charliebrown]

yep alright, so pretty much ask them for 205/50/15 if it can be fitted, and if not... 195/50/15?

[markismaximus]

I would try stick to the 205/50/15 as its closer to the original size. Looking at the nankang website as reference it appears that tyre will fit on a 6.5" rim

http://www.nankangtyres.com.au/tyre1/ns-2.php

[Lukey]

195/50 will most likely have a load rating lower than 86

[charliebrown]

195/50 will most likely have a load rating lower than 86

Does that depend on the brand as well?

[vinnY]

^ as far as I know load rating is dependant on size only

fitment wise, if it really is 195/60/14 then your best bet is 195/55/15 on the new rims

[markismaximus]

^ as far as I know load rating is dependant on size only

fitment wise, if it really is 195/60/14 then your best bet is 195/55/15 on the new rims

No it wouldn't be. A 205/50/15 is a closer diameter to the stock diameter than a 195/55/15.

Also according to Bridgestone only a 205/50/15 would meet the load rating of 86

[vinnY]

^ I stand corrected, forgot the sidewall on the 205/50 is actually shorter than the 195/55

[Lukey]

Does that depend on the brand as well?

some brands will have extra load or XL on the sidewall and on there website. but i havent found one of 86 on 195/50r15 before

[charliebrown]

Alright thanks mate, ill call some shops and ask them for prices on 205/50 R15 with 86 or higher load rating