Topic: Tire Aging and DOT code
in Forum: C3 Engines, Driveline and Handling
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This is a good topic that I missed when it was shown on 20/20 last year.
See link below for article and video on tire DOT codes and tire aging issues. I have been shopping for tires on another vehicle recently and found this knowledge helpful to be sure I was getting new manufactured tires.
How old are your tires on the vette (based on DOT code)?
0-5?
6-10?
over 10 years?
Do you replace at 6 years or some other factor/age parameter?
1980 L82 (5069 made), Dark Green Metalic (844 made)
Gymkhana Suspension, AM/FM/CB, Sporting a ZZ383.........
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Thanks, Bernie. Some good information to know. 
Larry
The difference between men and boys is the cost of their toys!!
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Great post.....thanx!
corvette440hp
Lifetime MemberModerator
Moses Lake, WA - USA
Joined: 4/16/2005
Posts: 2134
Vette(s): 1976 L48 4-spd, Mahogany Metalic exterior, Buckskin interior 350ci/350hp, 3rd owner, fiberglass spring, 255/50-16's Torq-Thrust II
It is great information! The tires on my vette were 12+ years old when I bought it. I changed them shortly after discovering their true age. Still had 75% of the tread left, but was not worth the risk.
Lifetime MemberIrving, TX - USA
Joined: 8/21/2004
Posts: 4273
Vette(s): #1 -1969 Corvette Coupe Riverside Gold, black interior,MN,A/C,350/350,PS,PB,window cranks.
#2 -2000 C5, black/black, 6 sp, Bose system & lots of buttons.
Good info! I found out the hard way and ran some old Dunlops that were on my car when I bought it. 
greypoupon69 2009-01-25 20:16:33
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MICK - C3VR Lifetime Member #113
OK, so what is the consensus? Buy new every 6 years? 10 years? 12 years?
1980 L82 (5069 made), Dark Green Metalic (844 made)
Gymkhana Suspension, AM/FM/CB, Sporting a ZZ383.........
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20225
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
My opinion...not based on any scientific fact/research...
I think a lot of this depends on how the tires are used/stored. ANY tire that is subjected to the weather/ultraviolet rays is gonna deteriorate quickly, compared to tires that rarely get out of the shade. Sitting in one spot for long periods also contributes. High speed runs when cold effect them. Under/over inflation, products such as tire dressings/shiny stuff, grease-oil-brake fluid....you name it, it ALL contributes to the aging of the rubber.
I don't like buying tires...I also don't like blow-outs @ 70mph.
A good quality tire will obviously last/wear better than the "4 for $100" deal at Pep-Gurls.
The tire on the '74 have been on it since 1997...I put them on meself. They've got maybe 5000 miles on them, and the car is always in the garage, and covered, with the exception of the few times it's been on road trips, or at local shows. The tires are still "new", treadwise, and have no sidewall cracking, or any other indication of deterioration. So I trust them to make a long road trip now? You betcha. That's just me.
The tires on the '85, however, are different...it sits outside all year, and even tho it is covered, the tires do get weather. I've replaced the '85 tires 3 times since I've had it, and I bought it in '98.
Don't take risks with your tires...if you have to ask "Are they still good?", then they prolly ain't...
I think a lot of this depends on how the tires are used/stored. ANY tire that is subjected to the weather/ultraviolet rays is gonna deteriorate quickly, compared to tires that rarely get out of the shade. Sitting in one spot for long periods also contributes. High speed runs when cold effect them. Under/over inflation, products such as tire dressings/shiny stuff, grease-oil-brake fluid....you name it, it ALL contributes to the aging of the rubber.
I don't like buying tires...I also don't like blow-outs @ 70mph.
A good quality tire will obviously last/wear better than the "4 for $100" deal at Pep-Gurls.
The tire on the '74 have been on it since 1997...I put them on meself. They've got maybe 5000 miles on them, and the car is always in the garage, and covered, with the exception of the few times it's been on road trips, or at local shows. The tires are still "new", treadwise, and have no sidewall cracking, or any other indication of deterioration. So I trust them to make a long road trip now? You betcha. That's just me.
The tires on the '85, however, are different...it sits outside all year, and even tho it is covered, the tires do get weather. I've replaced the '85 tires 3 times since I've had it, and I bought it in '98.
Don't take risks with your tires...if you have to ask "Are they still good?", then they prolly ain't...
Joel Adams
C3VR Lifetime Member #56 
My Link 
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
The tires on "The Toy" were installed in '04 before going to BG for the 1st C3X. The tires that were on the car when I bought it in the spring of '00 were starting to show their age tread-wise (I don't know when they were made tho') so I wanted new rubber to be safe on the trip.
The tires on "The Beast" when we bought it in the fall of '06 were the originals. Even though they had just 7,500 miles on them (still have a lot of the new tire nubbies) and the car was supposedly stored in a climate controled garage there were checks and cracks in the tread grooves. Replaced them before the trek to CC in '07 knowing that we were going to put on around 5k of high speed driving in temps that were going to be in the triple digits (bagged and stored the originals incase the next 'caretaker' wants them).
The tires on "The Beast" when we bought it in the fall of '06 were the originals. Even though they had just 7,500 miles on them (still have a lot of the new tire nubbies) and the car was supposedly stored in a climate controled garage there were checks and cracks in the tread grooves. Replaced them before the trek to CC in '07 knowing that we were going to put on around 5k of high speed driving in temps that were going to be in the triple digits (bagged and stored the originals incase the next 'caretaker' wants them).
The tires on "BIGBRRD" when we bought it in the fall of '04 were replacements and had a lot of tread on them, but two had gone 'out of round'. Don't know what caused that (probably too much sitting) but all were replaced during the make-over.
All three cars are garage kept so the only weather they see is when they're out being driven. I up the air pressure a bit and clean both sidewalls before the cars are stored over the winter.
I've been told that rubber hardens with age (and this was certainly true about the tires on "The Beast") which reduces their gripping factor. So will just have to check them every year and replace as needed (especially when it gets easier to break 'em loose when launching! ).
).
Jim Olson 
"The Toys"...!!! Save the Wave! 
The tires on our Vette looked great when we bought it. However, they were Jetsons and I just wanted to change the tires because I didn't trust how old they were. Imagine my suprise when my tire guy came out and told me the tires had a build date of 1988! He said I was rolling on time bombs! By the way, I got the Firestone Indy 500. I love those tires!
Barry
I bought my '81 in '85 with the original Eagle GT's on it. I drove the car in a gymkhanna competition (you really learn alot about handling) and after that the tires were pretty much beat to #$%@. They still looked good, but they wore very prematurely. That was in about 1989, and in 1992 I installed a new set of Eagle GT's which were hard to come by because by then Goodyear discontinued the GT's and replaced them with the GT II's (I preferred - and still do - the rasied outline letters of the GT's).
I moved from Long Island to Atlanta in 1997 and trailered the car here. Since then, I hardly drove it because it wouldn't pass an inspection w/o the cat on the car. Prior to the move, the car was mostly driven to and from shows (with 10 trophies to prove it). In GA, once a car is 25 years od it no longer requires an inspection - of ANY kind, so...
...a couple of years ago I subjected my car to a mechanical restoration. Even though it had only 25,000 miles on it, due to lack of driving it really needed to be freshened up. I've written about that elsewhere in these forums. Back to the tires...
As part of the rejuvination project, I bought a new set of Eagle GT II's, even though the GT's still looked new and had very little wear. I read about tire life, etc. and decided for the sake of safety it was a wise decision to replace them. I must admit that the GT's still look better than the GT II's, but now I am not worried about driving the car with it's new-found performance :-). I like the idea of peace of mind while driving fast.
I tagged and bagged the original GT's and they are now stored comfortably in my basement, ready for a time in the future when this car may find itself someplace for display, but I don't expect that will happen, at least not for a loooonnnggg time.
Oddly enough, the new tires have this brownish edge all around the letters that I can't seem to remove. I've tried Wesley's Bleach White and Brillo pads, but I just can't get them looking "show quality." Perhaps I have to find one of those white letter pencils or something. That is unless any of you have another idea...
Jim
in Forum: C3 Engines, Driveline and Handling
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