While out on the highway today I experienced a rear tire failure on my 69 Buick. Part of the tread went missing and the steel cords frayed and started to slap inside the wheel well. This is a P215/75R15. Brought car to a controlled stop and the tire stayed inflated. Put on the spare, which appears to be the original unused spare ( blue still covering the whitewall and the little rubber stubs still on the tread ). This is a 8.55 x 15.
Question: Are the P215/75R15s the correct replacement for the original 8.55 x 15? What cold pressure should we be running radials at when they are installed on our old cars? Ted
8:55 is actually closer to P225/75R-15 radials "squat' and so the distance from the centre of the rim to the ground is less than the distance to the top lol Bias do not squat
Thanks Carl. Here's the second part. Trying to figure out how long these tires might have been on the car. Found these numbers on the tire *A3HFDHB11* and DK-26944 and DK-27453. Is the date embedded into these numbers somewhere? Ted
Thanks Carl. Here's the second part. Trying to figure out how long these tires might have been on the car. Found these numbers on the tire *A3HFDHB11* and DK-26944 and DK-27453. Is the date embedded into these numbers somewhere? Ted
Yes
Determining the Age of a Tire
When it comes to determining the age of a tire, it is easy to identify when a tire was manufactured by reading its Tire Identification Number (often referred to as the tires serial number). Unlike vehicle identification numbers (VINs) and the serial numbers used on many other consumer goods (which identify one specific item), Tire Identification Numbers are really batch codes that identify the week and year the tire was produced.
The U.S. Department of Transportation (DOT) National Highway Traffic Safety Administration (NHTSA) requires that Tire Identification Numbers be a combination of the letters DOT, followed by ten, eleven or twelve letters and/or numbers that identify the manufacturing location, tire size and manufacturer's code, along with the week and year the tire was manufactured.
Tires Manufactured Since 2000
Since 2000, the week and year the tire was produced has been provided by the last four digits of the Tire Identification Number with the 2 digits being used to identify the week immediately preceding the 2 digits used to identify the year.
Example of a tire manufactured since 2000 with the current Tire Identification Number format:
In the example above: DOT U2LL LMLR 5107
DOT U2LL LMLR5107
Manufactured during the 51st week of the year
DOT U2LL LMLR 5107
Manufactured during 2007
While the entire Tire Identification Number is required to be branded onto one sidewall of every tire, current regulations also require that DOT and the first digits of the Tire Identification Number must also be branded onto the opposite sidewall. Therefore, it is possible to see a Tire Identification Number that appears incomplete and requires looking at the tires other sidewall to find the entire Tire Identification Number
The use of a partial Tire Identification Number on the one sidewall (shown above) reduces the risk of injury to the mold technician that would have to install the weekly date code on the top sidewall portion of a hot tire mold.
Tires Manufactured Before 2000
The Tire Identification Number for tires produced prior to 2000 was based on the assumption that tires would not be in service for ten years. While they were required to provided the same information as todays tires, the week and year the tire was produced was contained in the last three digits. The 2 digits used to identify the week a tire was manufactured immediately preceded a single digit used to identify the year.
Example of a tire manufactured before 2000 with the earlier Tire Identification Number format:
In the example above: DOT EJ8J DFM 408
DOT EJ8J DFM408
Manufactured during the 40th week of the year
DOT EJ8J DFM 408
Manufactured during the 8th year of the decade
While the previous Tire Identification Number format identified that a tire was built in the 8th year of a decade, there was no universal identifier that confirmed which decade (tires produced in the 1990s may have a small triangle following the Tire Identification Number to identify the decade).
Since yours are before "two digit" 2000 so yours are either 83-84 or 93-94 C2
-- Edited by 427carl on Saturday 31st of July 2010 10:30:38 PM
427Carl, that is great information to have. I know people store their vehicles in all kinds of conditions but is there a rule of thumb for how long tires can be safely used?
427Carl, that is great information to have. I know people store their vehicles in all kinds of conditions but is there a rule of thumb for how long tires can be safely used?
Interesting question..
When I was running my own store, we would often, have tires in stock for several years.. The tires were always stored dry and dark.. In 06 I ordered RV (19.5's) tires from Michelin and the serial number indicated 02 tires Its always condition!!! If tires are not cracked, they are good to go... I would change tires more often, on cars that are runnimg more miles on major highways ... look at the outside and inside each year( for cracking) If any question have a dealer look, or just replace them and send old tires to me...
