So Im going to get some rimmage goin on..

I love the ride and performance of the stock 18's on my Performance....

I would like wider wheels... I am definalty going to get some 8.5's in the front.. and either 9.5 or 10 in the back (which will fit best in volk te-37?)

So yeah, What will give me better performance...

18's or 19's... out of the same type of wheel

18's are lighter / rubber is harder
19's are heavier / rubber is softer...

hrmmm

THANKS

 

my $.02 worth.....

19s will decrease performance. You are moving the moment of inertia (majority of the weight) farther away from the center of the wheel, thus making it harder for your car to get the wheel rolling. Even on lightweight wheels like the TE-37.

Also, the aspect ratio of 19" tires will be a lot smaller than 18" tires, making your ride more harsh. I think you are trying to rationalize that in your "rubber is harder... rubber is softer" comment, but that's not quite correct. Since the sidewall of the 19" tire will be shorter than that of the 18" tire, the tire will absorb less of the impact from road irregularities.

19s do have a certain look that might be more appealing than the 18s. For pure looks, the 19s may be the way to go.

There have been a thousand threads about what size to get... but what you will find it that 18x9 with about 30 offset is fine for the front and 18x10 with about 28 offset is fine for the back.


Hope that helps...

PeteH

 

^^^^^^^^^^^^^^^^^^^^^^

Thanksalot for that reply!

Generally on thiner tires ( 45 vs 35 ) the rubber is softer on the lower number... am i wrong? so on 35s on 19's will wear out faster then 40's on 18's...


on the search for some 18's now

 

19's more rotational mass = slower acceleration
19's bigger diameter = better cornering

this has always been my view on 19's.

 

Not exactly... the number that indicates the wear rate is the USQC number... usually something like 140 or 180 or 220. This is the treadwear indication number and is not consistent among all tires. So, a TOYO with a treadwear rating of 280 may wear down faster than a Michelin with a treadwear rating of 220. It just depends ont he tire and how you drive.

I have TOYO T1-S on my Z... 245/40-18 front and 255/45-18 rear. The rears have been through three track events and about 3500 street miles and they are down to the wearbars. I think the treadwear rating is something like 280!



That's the fun part!

PeteH

 

Yep... better cornering becasue the sidewall is shorter and stiffer. But, at the track that can be a detriment since the tire will tend to scrub in a straight line instead of rolling onto the sidewall. You want a little flex at the track. Most racers are using 17" wheels on the Z with a 255/40-17 on the front and rear or 275/40-17 on the rear.

On the street... 19s do look really good, but you probably won't win any stoplight drag races.

PeteH

 

I thought the 245/40-18 the 245 part was the width...

oy

 

245 is the width. The series of the tire ie: 45, is the percentage of height of the sidewall in relation to the width of the tire.

 

freeze is correct.... and none of those numbers have anything to do with the hardness or softness of the rubber... the treadwear rating will give you some idea of the expected longevity of the tire

the point I tried to make earlier is that my TOYOs have a treadwear rating of 280, yet the rears (255/45-18) only lasted me 3500 miles.

The SO-2s that I just bought have a treadwear rating of 140. This would indicate a softer compound than the TOYOs with their 280 rating. This also means the SO-2s will wear out faster. That I bought 255/40-18 for the rear instead of 255/45-18 has no bearing on how hard or soft the rubber is....

PeteH

 

3500miles???

you must do alot of racing.

I have 4000 miles on mine, and they show very little signs of wear.

 

Mike, that second statement is a little deceiving. The larger wheel diameter improves steering feel, but will actually decrease the cornering ability of the car. A super-short sidewall doesn't allow a radial tire to flex (like it was designed to) and so the footprint won't distort (i.e. get bigger). Another side-effect is that rubber-band-tires have a small slip angle: this makes the difference between a tire griping and sliding razor thin. Finally, a larger wheel is also more susceptible to damage by pot-holes (there is a reason why the OEMs don't put dubs on their cars).

The F1 guys use huge tires and small wheels to achieve their 3g's of cornering madness.

 

that's from a full weekend and one day at Texas World Speedway and then one day at Texas Motor Speedway. At least 1000 miles just on the track for the poor rear tires.

I run in the advanced run group so I'm really giving the car a workout. You should see my front tires. I've already gone through two pairs of 245/40-18 T1-S in the front. This car really needs more front camber!

PeteH

 

Aren't those F1 wheels 13" in diameter??? I thought I read that somewhere... they sure look small with that giant tire on them.

 

I think their rims are just large enough to hold the rotors, and no larger.

 

so not true come on they arent gonna slow your car down that much from 18's and most likely if you are buyin TE's or something like that you will have more on your car then just rims... I know this wont stop any of the nitrous kids, or even some of the NA boys and girls... hell even if you put them on a bone stock Z it would still be quick...

-non