Do you ever change the Spare Tire Rubber?

I was checking my spare tire in the trunk before a trip.
It looks original from 1998, untouched in pristine condition (never used before!).

Of course you hear all kinds of story about not using tires more than 4-6 years old etc. for risks of tire failure/explosion from aging process. But we are talking about tires on the road, exposed Sun Rays UV light (which degrades the tire rubber).

The spare tire is in a protected environment (trunk). In my previous 1983 735i, I kept the spare tire until 2005 (17 years later it still looked OK in the trunk!).

So the main question for all you folks is: Do you ever change the Spare Tire Rubber?

Tires have an expiration date, you need to check it.

When you have a full size spare (with matching wheel) there's a rotation pattern that includes the spare. Take a look here I don't think i've ever done it, and i'm pretty sure it only works for non-unidirectional tires.

That being said, i think, since the tire is in the trunk, sealed from the evil sun, i think it's fine. I've driven on full size spare tires that were over 15 years old, without any issues.

On another subject, i'd NEVER drive my car more than a few miles on a temporary spare. My father ran the wheel and brake lab at Ford for over 10 years, and he told me horror stories about how inferior the tires and wheels are that you get in your trunk. They ain't lying when they say "don't exceed 50 mph".

I think every 10yr or so, may not be a bad idea to replace the factory spare tire with some cheapo tire?

Just use it a intended: as a spare, in an emergency. As long as it holds air, I wouldn't worry about driving on it while getting the blown tire plugged or replaced. Just don't use it as a permanent replacement.

Yep. Just make sure you check the inflation. Last year I had a flat on my truck on the West side of Snoqualomie Pass in Washington. Stupidly, not having checked it for several years, the spare didn't have any more air in it than the one I took off. Lesson learned.

I hope I never have to find out. But, it might be interesting to see how it handles, if I ever get a flat on my E39 though. The spare in the trunk is the brand new original, but it is an inch smaller than the tires/wheels I am running. I'm sure it will serve just fine as a spare. But, only going slowly.

1+,

I checked my spare pressure once a year, every Spring.
I use masking tape and place it at door jamb saying " spare ck Apr. 2010".
So at a glance I know right away when the spare was last ck.

The tyre should be replaced when it expires. The rubber degrades. This is why it's important to look at the date of manufacture of any tyres you buy for the car; often they've been sitting for a long time. 5 wheel rotation is the best thing to do, second best is to buy a cheap tyre, third is to buy a lightly used tyre. Having an old tyre defeats the purpose of a full-size spare.

Checked the pressure in the spare for the first time (!) a few months back and found it empty. Don't forget it's there!

Originally Posted by bmw_n00b13

The tyre should be replaced when it expires.

I don't doubt a tire needs to be replaced "when it expires" but ... the only date I know of on a tire is the manufacturing date (and even that, IIRC, is cryptic).

Most manufacturers recommend 6 years.

What's the "expiration date" for BMWs?



TO FIND THE MFG DATE:
First, you find the line of print beginning with DOT and look at the end of that serial number sequence:
- If there are four digits then the tire was made in 2000 or after. (4805 means the 48th week of 2005; 0401 means the 4th week of 2001)
- If there are only three digits then the tire was made in the 1990s. (347 means the tire was made in the 34th week of 1997.)
- Lord help you if you only have two digits!

I had some dunlop s2000 in storage that I bought 7 years ago with 5k miles only on them that I used to replaced my worn out continentals. A month after I took it to the shop due to a nail on right front tire. I wanted it scrape and patch so as the tech was trying to separate the tire from the wheel, BOOM! my side wall ripped!
Boy I was pissed! The manager started explaining to me that my tires were 7 years old, at first I didn't believe the theory until 2 more sidewall ripped when they tried to dismount it.
So I ended up buying 4 brand new tires because of a nail, talk about blessing in disguise!!
Those tires could have blew up on me on the highway!

Short answer: No.

I have seen tires that are 20+ years old that hold air and are driven on a daily basis. We are talking about a spare here. Check the air pressure every time you change the oil and keep it at the max. Inspect it for dry rot (small cracks). You will be fine. If it starts loosing air quickly, more than 5 psi every few months, then start considering replacement. Otherwise, don't waste the money.

Originally Posted by topgear454

Short answer: No.

I have seen tires that are 20+ years old that hold air and are driven on a daily basis. We are talking about a spare here. Check the air pressure every time you change the oil and keep it at the max. Inspect it for dry rot (small cracks). You will be fine. If it starts loosing air quickly, more than 5 psi every few months, then start considering replacement. Otherwise, don't waste the money.

Exact comments were made to me last year by a tire supplier. Use only for "emergency". Dry rot is the main reason to replace.

I still have the original Dunlop spare for my '89 E34. No signs of dry rot.

Keep it pumped up is all I do. For the amount of miles that you put on a spare in a year is it really worth buying a new one?

Well,

The only time this is worth anything is in the middle of nowhere and the spare time you just installed blows because of its age.
This is why I started this thread....

cn90 I'm sure you're aware that cooling systems and tyres only go bad in the middle of nowhere

Bluebee, good call. There is no date in the US. In Europe, manufacturers recommend rubber no more than 6 years old. Japan cuts off at 5 years old. Never buy rubber that's over 6 years old.

In a letter released September 22, 2003, a private safety group called Strategic Safety asked the National Highway Traffic & Safety Admin. (NHTSA) to investigate the problem of tire aging. The group says they have documented at least 20 accidents caused by old tires blowing out, 10 of which resulted in fatalities. Most of the lawsuits involving these tread separation accidents have been on tires that were six or more years old.

I think that driving with old rubber as a backup is like replacing your radiator with a used one, or some similar simile. You're asking for trouble.

Originally Posted by bmw_n00b13

cn90In a letter released September 22, 2003, a private safety group called Strategic Safety asked the National Highway Traffic & Safety Admin. (NHTSA) to investigate the problem of tire aging. The group says they have documented at least 20 accidents caused by old tires blowing out, 10 of which resulted in fatalities. Most of the lawsuits involving these tread separation accidents have been on tires that were six or more years old.

Of the 20 accidents, how many of the "old tires blowing out" were the spare? Do you have the documentation of this report?

I have a 1982 Fiat Spyder w/ 37,000 miles. I replace the tires every 5 years/10K miles because they are exposed to the elements. Based only on tread depth, I could get an additional 10K.

I agree with those of you who make the point to replace old tires, just not an old spare that is in good condition. If you agree with the theory to rotate 5 tires, then I doubt that you will get over several years of use out of that 5th tire.

When a man who makes his living selling tires tells me that I don't need to replace my spare unless it leaks or shows cracking and dry rot, I listen to him. YMMV.

Bringing back an old thread.

2011-2012: my spare tire lost about 5 psi (from 40 psi to 35 psi in 1 yr).
2012-2013: lost all air, down to zero psi.

Visited local tire shop which has been around town for 30 years, the owner told me as long as the tire is in the trunk (and used only as spare, and not for extended period of time), it is protected from:
- Ozone
- Road hazard
- Sun/heat damage

It will last a long time.
Sure enough, we looked at the factory spare tire (dated July 1997!!!), it still looks good, no sidewall cracks, good tread depth.
The only thing broken was a cracked valve stem.

So he changed the valve stem, cleaned the wheel lip (where it meets the tire), remounted the tire.
Charged me $10 and all is good.

BTW, check your spare tire twice a year (Spring/Winter), change valve stem every 12 yr or so.

When I had factory wheels I would save the better tire off the front set each time and make that my new spare.

Originally Posted by abanjableu

When I had factory wheels I would save the better tire off the front set each time and make that my new spare.

Great idea!
The only problem with my car is: the 4 road wheels are 17", the spare is 15"!

If you want to spend ~$100 on a tire for a spare that you probably wont ever use and if so, for no more than 50 miles then changed it. Thats just my take. Personally I wouldnt change it only because I'm never more than 20 miles from my house or dorm up at school so a 15 year old spare would work fine for my situation.

I too was recently wondering about my spare. In the 5 years I have had the car I have put a few hundred miles on the spare due to circumstances and laziness getting a replacement.

At least once a year I drive 900 miles to Houston, TX. And knowing that if I got a flat I would put on the spare and not replace it until I got back home could be 1800 miles on a 15yr old spare at 70-80 mph.

Crossing my fingers hasn't gotten me killed yet, so I'll probably just keep chancing it. Maybe next year...

My spare is a ragged piece of garbage. I plan to have it replaced once I swap back over to my summer rubber.