Kumho KU36's

**doosra** · 26-04-2011 05:47 PM

Originally Posted by euromandeluxe

^ that's pretty narrow, you stretching?

I've got 235's on the rear but 205's on the front. I purchased the car with these tyre specs already so im just keeping with them. Car is lowered as well, so maybe he had 205 so there's no camber wear and scrapping.

My fronts are 205/45/17 and rears are 235/45/17. My rears tyres are new so only fronts need replacing. What is the ideal tyre size recommendation keeping in mind it's lowered?

**greek_rambos2k** · 26-04-2011 06:02 PM

Originally Posted by doosra

I've got 235's on the rear but 205's on the front. I purchased the car with these tyre specs already so im just keeping with them. Car is lowered as well, so maybe he had 205 so there's no camber wear and scrapping.

My fronts are 205/45/17 and rears are 235/45/17. My rears tyres are new so only fronts need replacing. What is the ideal tyre size recommendation keeping in mind it's lowered?

hellooooo. the tyre sizes you are running arent the best. your fronts are fine width/45r17 but your rears need to be width/40r17. running 45s on the rear means ur car is going 4.7% to slow so if your going 100kmh your actualy going 104.7kmh. rather if you use a 40 ratio your going only 0.7% slow which means if your speedo says 100kmh your going 100.4kmh. much more accurate. so yeah when you get new tyres fix that little problem...

**9large** · 26-04-2011 06:52 PM

Originally Posted by greek_rambos2k

hellooooo. the tyre sizes you are running arent the best. your fronts are fine width/45r17 but your rears need to be width/40r17. running 45s on the rear means ur car is going 4.7% to slow so if your going 100kmh your actualy going 104.7kmh. rather if you use a 40 ratio your going only 0.7% slow which means if your speedo says 100kmh your going 100.4kmh. much more accurate. so yeah when you get new tyres fix that little problem...

Your calculations are incorrect, unfortunately. All else being equal, compared to AP1 stock dimensions, 235/45R17 is fine on the rears, but 205/45R17 has a slightly smaller rolling diameter than the stock 205/55R16 size.

To calculate the rolling diamter in mm, multiply <wheel diameter> (in inches) by 25.4, then add 2 x <tyre width> x (<profile>/100).

e.g. rolling diameter of 235/45R17 = 17 * 25.4 + 2 * 235 * 45% = 643.3mm

Note, the rolling diameter is not the circumference.

**greek_rambos2k** · 26-04-2011 06:55 PM

i used several calculators to do it? hmm weird (when i say calculators i mean wheel calculators not like yehh the normal maths one. lol) my bad

**doosra** · 26-04-2011 09:24 PM

After all the calculations, what tyre size do u guys suggest for fronts? With wider rims do u think they'll hit my guards?

**9large** · 26-04-2011 10:24 PM

The answer is, it depends.

For road use, conservative sizes you may use are: 215/45R17 fronts and 245/40R17 rears. Something slightly more lively: 245/40R17 fronts and 255/40R17 rears.

The width of your rims naturally play a part, but it's the width of your tyres that primarily determine if your fenders need modification.

There's so much info about S2000 tyre fitment - try searching the forums on OzHonda or s2ki or even Google if you need more info.

**doosra** · 26-04-2011 10:44 PM

My rears still have lots of tread so I think I might go with 215/45/17 fronts and leave my 235/45/17 rear.. Checking out tyre calculators this is probably best option..

**dlai5552** · 27-04-2011 01:21 AM

I think you should go with 235/40 as it looks better and also doesn't mess with your speedometer as much as the 45's will!
I plan to get 235/40/17 for 17x9 wheels, but in Dunlop direzza star specs. You should go for star specs!!

**9large** · 27-04-2011 07:59 AM

Both 235/40R17 and 235/45R17 differ from the stock AP1 rolling diameter by about the same amount - 1.84% and 1.88%, respectively. Looks are one of the last things you should worry about when it comes to your tyres Lol. But it's besides the point as his rear tyres are new.

**dlai5552** · 27-04-2011 09:48 AM

where do you guys get this tyre calculator? help please?
I'm trying to figure out how much harder it will be to fit, 255/40/17 on my s2k compared to 235/40/17.
Do you guys think it will have much of a difference in performance in the end?

**euromandeluxe** · 27-04-2011 10:06 AM

for your 17x9? what's the wheel offset? need that to determine if it will fit.

Performance depends on what you're after. What's your front tyre size? What's your current rear size? Do you find the rear to be taily? Wider rears will (generally) mean more rear grip and less oversteer tendency.

this is the tyre size calculator i use:

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