Just wondering if any one ever tried running 305-30-19 insted of the 315-25-19.

I have a friend that wants to sell me his rubber and I am wordering if I should do it...

 

you need to know the manufacturer and compound of the tire so you can determine the circumference compared to that of your front tire...the higher profile may cause a problem with AWD....I think the tire rack website has info on circumference and your owners manual will specify the acceptable spec range between front and rear

 

Thanks Chuck!!
Ill check it out!!

 

yeah I thought about 305 tires as well...I think the rolling diameter shouldn't be any more than 25.5 I remmember reading on one of these threads...so the key is to measure the rolling diameter on the 305, then find a front tire with just around the exact same...and within the tolerance of the what the car needs...

 

Jay I just pm'ed you

 

I ran a bridgestone re-11 in that size on the rear, combined with a 255/35-19 front.

 

a 255/35-19 up front....did that rub anywhere? I would think that's too wide of a front tire for 996tt?

 

the width doesn't matter for this problem it's the profile that counts he is just saying if you go 30 in the rear you need a 35 in the front not a 40..but that only applies for a Bridgestone RE-11...the circumference still could be different for a different manufacturer with the same tire size

 

No rubbing, I would really like to go to a 265/35-19 as it's a better fit with a 305/30-19 and those two sizes come in R-comp tires that match. But I won't put that on a 8.5" front wheel...I felt the wider tire up front really helped on the track, the trade off is the car tends to 'track' the road imperfections more. I tracked the car heavily and never had an issue with these sizes.

Agreed, you need to be careful matching sizes as it's all about overall diameter, tire rack has some good info but always check with the manufactures website and data as well. Math is only part of the equation as tires vary a fair amount.

 

yes i run 305 30 19
car drives like its on rails
MUCH better than a 315 25 19

 

to really help please specify manuf and type (i.e. Michelin PS2's) and at least the profile of your front tire..thanks

 

here's what i run 235/35/19 and 305/30/19 on mine and it's at 2.9% which is ok. rule of thumb is no more than 5.0%
http://www.miata.net/garage/tirecalc.html

 

Here's another link: http://www.1010tires.com/TireSizeCal...?action=submit

 

I'm running Michelin PS2 in 305/30-19 in rear and 225/40-19 in front.

 

235 35 19
305 30 19 Bridgestone Potenza (oem tire for the 997tt)

in the 3 years ive had my car, these tires have made it the most pleasant to drive.
i have a 12" rim in the back, and for some reason, 315s would stretch (about 2 years ago, i was posting non stop about different tire options etc etc, because my didnt feel connected to the road)

the taller sidewall REALLY helps with feeling the car, as does the fact that it has n1 stamped on it (porsche specified, harder compound)