Quote:
Originally Posted by CapriRacer
First, the date of manufacture is on tires - even donut spares! It's encoded in the TIN (Tire Identification Number) commonly called the DOT number. The DOT code is a 9 to 13 digit code that is located near the letters "DOT". More detail here: http://barrystiretech.com/dotcoding.html
Short version: The date code is the last 4 digits in a week/week/year/year format. So a 3115 is the 31st week of 2015.
An 18 year old tire coming apart is due to the age, not the inflation pressure. Over time, the rubber loses adhesion to the steel belt. That's why tire manufacturers recommend replacing tires after 10 years - and sooner in some instances.
So check your 12 year old Accord spare for the manufacture date. I'll bet its original to the car.
And just an FYI. the burst pressure of a tire is many times the max pressure. Even that 60 psi donut spare will not burst until over 150 psi - except when it gets damaged or is very old!
So what to do about that failed spare? Tire Rack does sell donut spares. If they don't have the size, you can try something close or get a regular wheel and normal tire. |
Thanks Barry!
My concern was not bursting the donuts, although I wasn't sure just how high above that establashed Max. the bursting point was.
Which leads me to another question:
At this point I'm fairly knowledgeable, thanks to you and other experts, of how vehicle mfgs. arrive at the recommended/specified cold tire pressures printed on the Tire/Load placards on their vehicles.
So, my question is, by what process do tire mfgs establish a Maximum Inflation pressure for their products?
IE: If the bursting pressure of a given tire is 'B'psi, then how do tire makers determine how low to set that published Maximum Inflation point 'M'psi?
My formula 'M = B/2' (or B/3 or B/4)