When to replace tires?

[86911c2]

I purchased a 1986 911 Carrera in Semptember of 2005. The tires that came with it were Bridgestone Pontenza S03 Pole Position - Front 20555ZR16, Rear 22550ZR16.

The previous owner had purchased these tires in June of 2002, and they currently they have less than 5000 miles of use. The treadware is fine and there are no signs of cracking on the side walls.

I have been happy with the performance of the tires, and from what I can tell by reviews and other posts on this forum, they are pretty decent tires.

A friend of mine recommnded replacing them because of age (they will be ~5 years old when I take it out of storage this spring). Does this makse sense, and at what age do you need to replace tires in general?

Is there a way to check (besides treadwear) if a tire needs to be replaced?

[porsche930dude]

If there not worn or dry rotted there is no reason they should need replacement. 5 years is not that old. my freinds honda has tires on his accord from 1991 and amazingly theyre still good as new they are hankooks with almost 90k on them since new. My rears need replacement right now because one slipped a belt and they are both dry rotted. definatly not that safe for tripple diget speeds. Im leaning twords bfg ta kdw-2s.

[rgrimm]

I've heard "replace after six years." Especially if the car is stored outside in the elements.

FWIW, when I got the '84 a year ago, the tires were last replaced in 1988 (making them seven years old). Tread was low, but certainly not at the wear bars. My plan was to use them for another year, saving the money for other small projects.

A month after getting the car, I basically shredded a rear tire running with our local group at "spirited highway speeds". So I'm thinking "replacement based on time" isn't a bad idea.

[Kraftwerk]

Tires from 1991? Not a good idea.... but you pal might not find out until it is too late, tell him to get new tires, pronto.
I have heard between six and 8 years is the limit.

[tonythetarga]

You have to consider the 'duty' the tires will serve. If you are basically a pleasure driver with the occasional highway speed (or slightly higher) drive, then you are fine. If you plan to put them through a harder high speed workout on the track, I'd probably plan on new skins.

[Emission]

You can drive on tires without tread (they are just more prone to hydroplaning).

Don't drive on them if they are worn to the thread/steel, cracked, damaged, or out of round.

Age depends on how they were stored (inside or outside in the elements), how they were run (trailer tires, or track tires), and if the rubber has deteriorated.

I wouldn't suspect 5-year-old tires as too old yet. Can you post a close-up pic?

[86911c2]

Here are a couple of pics - may be hard to tell anything from these ....

Thanks for all of the replies.

[porsche930dude]

Originally posted by Kraftwerk
Tires from 1991? Not a good idea.... but you pal might not find out until it is too late, tell him to get new tires, pronto.
I have heard between six and 8 years is the limit.

Not to worry. His timing belt snapped at 140k and he plans to junk the car. there going nowhere fast. The poor sap that goes to salvage them from the junk yard will have to worry about them

[Quicksilver]

I find it hard to understand having the need to get one of these cars without having the need to lean on the cornering potential of the car.

Now if you are going to lean on the car buy something sticky! If you aren't going to lean on it...

Uhhh...

Now why did you pick this car again?

[Doog]

The vulcanization process never stops.. (regardless of storage conditions)

Id replace anything older than 5 yrs if you ever drive faster than 50mph..

[randywebb]

Ditto - you will be surprised how much stick you will gain with new rubber.

However, you might have some fun purposefully skidding around on the present tires at an AutoX or some other area closed to traffic (parking lot?) for a while. It is a good way to get a feel for the chassis dynamics of your car.