reno808

I want to know why does the 951 have to different tire height sizes. for example: 205/55/16 FRont and 235/50/16 Rear. What happens if i were to put for a example 205/50 and 235/50/16. with out doing any suspension mods.

Rich Sandor

reno: Tyre height is based on the tyre's width.

205/55/16 has a sidewall height of 55% of 205mm = 112.75mm

wereas 235/50/16 has a height of 50% of 235mm = 117.5mm

if you put a 205/50/R16 tyre, it would be 50% of 205mm = 102.5mm, which would be a much shorter tyre sidewall.

Matt_H can correct me if I'm wrong.. he's the Tyre expert in these forums...

reno808

I know that i would be shorter. but i want to know why is the front higher than the back is it because the way the car is. And then it would be level.

snappy

the reason the fronts are higher is cause the rears are wider. that way they try to level the car out.

as mentioned. only 2 out of the three listings are fixed.for eg.
225/55/17

225 is a fixed size.
17" is a fixed size
55 is a percentage or height based on the width of the tire.

reno808

what happens if i put the same size (height) wise??? if i change the suspension setup then i can put the same size on. The reason for my consern is because my friend gave really nice tires but they are 225/45/17 and 255/45/17 what would happen if put this size in my car now with stock suspension??

Rich Sandor

reno: read my post again. the front sidewalls are 112mm tall - which is shorter than the rear.

don't let the 205/55/R16 fool you. 55 is a percent of the width...

75% of 250 is less than 50% of 500.

Rich Sandor

reno: you should be fine with those tyres. the fronts will be a little short on the sidewall height, but the only thing is you notice is a slightly stiffer ride on the front... but that also depends a lot on the tyre itself.

reno808

yup thats what i expect. thanks

Ian Carr

speedo would be off... different top speed ext..

hally

compare your old and new tire sizes -

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

reno808

Thats that is a really good tool.

951North

What are your rim widths? Though these tires will fit on stock WIDTH rims 7" front, 8" rear (though they won fit stock rims obviously) they may exhibit some "balooning" in the sidewall. The 45 series in the rear is a little tall (~1/2"), for that tire width you should go with a 40 series. If you ran these tires the rear would sit a half inch higher and fill the fender gap another 1/2 inch.

According to a tire manufacture website, a 225 width tire will fit a 7-8.5inch width rim and a 245 tire on a 7.5 to 9 inch rim...


BTW the stock tires' sizes were the same overall diameters at 205/55/16 and 225/50/16 (24.9 inches)

jason.

reno808

iam fitting them on cups I's. with at 7inch front and a 9inch rear. what are the BEST tire size? what do you guys run??? and iam looking for performance gain too.

M758

Stock sizes are
944 Turbo
205/55 R16 Front (7x16) 225/50 R16 Rear (8x16)
944 Turbo S
225/50 R16 Front (7x16) 245/45 R16 Rear (9x16)


Who has the stock 968 sizes with 7.5x17 fronts and 9x17 rears?

Mike Buck

225/45 17 front, 255/40 17 rear

I run 235/40 and 255/40 RA-1's on mine at the moment. factory 968 cup 2's