Tires
 

Can someone tell me how to tell when its time to replace tires on this car? I have the stock Potenzas. Is there a wear indicator or something other than the obvious signs of wear on the sides?

.. Also how many miles do these stock tires generally get when driven reasonably and not really put through a lot of hard driving?
Thanks

Penny test. Take a penny and turn Lincoln head upside down and put it inside the thickest part of the tread. If you can see the top of his head then it's time to repalce the tires. But now there trying to say you need to see more than that.

Tread Test

I'll go first before the flames start........


maybe under normal driving anywhere between 18,000 to 20,000 miles.
others may say different. i'm at 16,500 on my 09. and trying for 23,000 to 25,000. I'm cheap. and i won't go back with the bridgestones to loud.

:iagree:

Does the penny test still apply to these low profile summer tires?

Yeah, pretty much. It's not really a good test. Just actually measure tread depth. If you deal with rain, replace at around 3/32's.

That's a lot of mileage to get outta them. Must have some nice roads!

I hit 18500 and mine where done.

I will say that by 15K you should have to replace your tires, especially if you do agressive driving. Some guys have not even reach 10K on the factory tires.

I just made 10k on my 350. But it was FI also with lots of abuse. That was on KDW's.

The fact that they are low profile doesn't change the way they are measured which is the same as any other tire.

The penny test is still valid and just like any tire that is legal for sale in the USA these tires are equipped with wear-bars to show when the tire is due for replacement.

As a side note, as long as the tires are reasonably fresh, typically less that 2-3 years old (as the tires age the rubber stiffens reducing traction), dry traction is actually enhanced as the tread gets thinner due to better support of the tread blocks and because the thinner tread generates less performance degrading heat. Wet traction, on the other hand, benefits tremendously from a deep tread that allows for superior water drainage to reduce hydroplaning and improve tread drainage. Recent tests (sorry, I can't remember which car magazine) indicate that wet weather performance declines significantly in the second half of the tread life due to the shallower treads' limited ability to flush the road surface of water.

In your case you'll probably change tires before they wear out because they tend to get very noisy in the second half of the tread life.

+1 Haha, ishibashi's idea of wear bar is very effective. Very loud. :D

Question: In dry weather are slicks (or heavily worn) the best? i.e. more surface area in contact with the ground.

In dry weather, yes. But unfortunately true slicks aren't DOT legal (at least I havent seen any) although you can get DoT approved R compound tires that are damn near slicks.I honestly wouldn't want heavily worn tires for any kind of aggressive driving.

Bunch of chickens....

Drive it until you see the shiny metal cords...

^^
I bought a used car once that had tires worn almost to that point. The literally looked like some one had taken a marker and drawn dark lines on it to make it appear like it had tread. Got stuck in the rain on my drive home, definitely the least fun I've ever had. It was like driving on ice for 4 miles at about 40mph (everyone with proper tires were doing 65 or so). I will never drive a car with what amounts to slicks in the rain again.

Pretty much yes. When autocrossing on street tires the tires get better as the tread wears off (less squirm) and are at their peak when practically bald and are done when you see cord. Throw in a couple of drops of rain though and you are going for a spin!

I used to do that back in Australia as they didn't have inspections in my state, it also didn't typically rain that much. I drove until I saw cords and then went down to the tire shop that sold used tires and put a "new" set on for $100. The one time it did rain and I gave it a little gas pulling out of a corner I did a 180 in the middle of traffic, had to quickly shove it in reverse and pull into a driveway :)

ran a set of hoosiers on the street for a while (too lazy to take them off)... man that got scary when they went all hard from too many heat cycles...

Hahaha when I was 19 and piss broke I drove on the steel belts in my 300ZX. Luckily, the tire blew when I was accelerating from a traffic light and not when I was at speed. I also remember driving on the highway during the rain and my car would hydroplane while changing lanes as my tires were running over the painted on dotted lines... That's how bad it was. Now, that I am older and more responsible and know I'm not invincible, I will never ever ever drive on tires that are worn to the point of rupturing or lacking traction.

I have 16k on mine and just received today my Hankooks from TireRack. I probably wait a few more weeks before I put them on, since I do not drive the Z in the rain and I feel the stock tires still have some life left in them.

23K miles, still have plenty of tread.

if you look in the cut out part of the tread. The lines that run around the entire tire. There will be a raised spot running sideways (touching blocks of raised tread). This is the wear indicator. If your tread is flush with that it is time for the tires to go. I tend to change mine out before it gets dead even. http://www.conti-online.com/generato...dicator_en.jpg