tires gone bad?

so here is what happened. i got a set of Falken ze-912 tires and they have lost almost all their grip but they aren't going bald anywhere. like, this weekend i was in Chapel Hill and the roads weren't even all that wet but after i went around a roundabout (not going fast at all and not touching the accelerator) the back end of my car slid out and the front tires weren't helping me out very much when i was correcting. i swung back and forth 3 times before i got the car under control (car's fine, don't worry.). i don't know what is going on, either way i'm planning on getting new wheels (rota p45r's ) with new tires. but if this issue is coming from something other than i might have bought a bad set of wheels or something i'd love to hear your input. i'd hate to get a new set of wheels and have the same bad situation happen. so right now i'm letting my Z stay in the garage because i'm worried if i ever have to slam on the breaks for some reason my car will just slide instead of stop.

all this being said, i am looking for suggestions on tire size and brand. i've had the bridgestone RE960's suggested to me as well as the B.F. Goodrich KDW2's. i'm kind of a rookie when it comes to sizing tires, and the wheels i'm getting are 30+ offset, 18 inches, and 9.5 inches wide. so if anyone here is a tire expert, i'm not sure what the best size tire would be to get. i don't like big sidewalls and that's about all i can say. i looked at sizing, so if this doesn't make since i'll just feel stupid. but would 245/35 or 265/35 work? if i'm wrong...... be gentle. ha ha.

did you buy them new or were they sitting up somewhere or on the car for a while before you started driving with them?and any signs of the belts seperating on them? dimples,bubbles of any sort?

look for any signs of dry rot. cracking and small slits at flex points, as we learned as kids with toys made of rubber it will harden after time (dry rot) and is less flexible. on tires it will seem as the compound chances a soft tire will take more time to wear and will have less traction than it should. there are many stages of dry rot and you can still use most tires as long as you know that they have changed and adjust your driving to compensate.




small cracks and slits = one more season use.

larger deep cracks (looks lice someone tried to cut them) = no more than a couple months.

bubbles blisters lumps belts shifting/pulling = get new very soon.



be careful when getting tires also 2nds are cheaper but you will have problems 9 out of 10 times. i have noticed toyo seems to send out bad batches more often in the past 5 years if you have or get proxies, neogen, or some of the older models look for silver dollar sized blisters on the sidewall. its usually on the lower profiles. 50 series or lower.




just in case anyone needs it.........



245.45zr18 = 245 wide, 45 tall (profile), z rated (speed rating), 18 rim size



i know most of you know this but i figured id throw it up anyway

as far as tire size for you.........................



first off how are the roads near you? if theres potholes and crappy road surfaces go with a larger profile (saves rim damage). a lower profile will make you feel every stone and bump in the road. most people think its there stiff suspension that makes a lot of noise and a loud bang when they hit the road "imperfections". its actually a combination of that and tire profile size. if you have any strange noises try a larger tire size(find some one who will let you borrow there factory wheel/tires). that will tell you if its the tire or suspension. i run a 255 40 zr 18 on the rear of mine. there not bad, very good ride and crappy road safe. as far as company??? goodrich, bridgestone, are both good but not really a favorite of mine. if had really good luck and performance with yokohama and kumho tires. but everyone likes something different.




ps. check your rear suspension to see if theres any damage to anything. or leaking struts.
that may cause the change in traction also. have you don any suspension mods? a stiffer spring may also cause your condition.



hope this helps and good luck

yeah thanks man, i really appriciate it. i haven't put any mods on my suspension. eventually i'm going to upgrade to coilovers, it's really a matter of cash for that one. unfortunately i can't just go out and check all these things you guys are suggesting, i'm at school and my Z is in chapel hill. but next time i'm in town i'll look at all of the things you guys have suggested. thanks for the advice! any other 0.02 would be appreciated, i'd like to have as much to check out as i can.

So where is your car? At Eric's? We need a tech day.

nah, my car is at my house. but yeah, a tech day would be fun

anybody know off hand what size lugs are on a stock Z?

12X1.25

sweet thanks

So it looks like you're gonna want either

255/35/18 or 265/35/18

evil zx(t) wrote:

i run a 255 40 zr 18 on the rear of mine. there not bad, very good ride and crappy road safe.

Sorry, what does "crappy road safe" mean?

i assume "crappy road safe" means they are safe on crappy roads. at first i thought it meant that the road safety was crappy but i'm pretty sure that it means they're safe on bad roads.

sorry, yeah i can minimize rim damage on crappy roads.

Gotcha