Tires: rotate radials, max mileage, 4 digits

Question
QUESTION: Hi There,

I have a H&H single axle trailer. I just noticed that the radial tires on it are wearing on the inside. I have figured out the axle needs re-cambering. As for the tires.... Can I / Should I reverse them on the rims and move them side for side to get max mileage out of them??? Or is this just a bunch of work for nothing?? Rotation on a single axle trailer not necessary? Or just do the side to side thing?

Interesting reply on the radial memory!

Bill

ANSWER: Bill,

You could reverse the side facing out - and switch them from side to side, but you need to be aware that recent bulletins from the tire industry indicate that tires degrade simply due to time.  The age of a tire is important even if the tire is unused.  There some disagreement over how to best express this age limitation, but my take is:

If you live in a hot climate (AZ, CA, NV, TX, and FL) then the limit is six years.  If you live in a cold climate (MN, ND, WI, MT, etc), then the limit is 10 years.  States in between are  ..... ah ........ in between.

Here's how to tell how old the tires are:

First locate the letters "DOT" on the sidewall of the tire.  Nearby will be the DOT code.  DOT codes are 10 to 12 digits long.  BTW the digits can be numbers or letters.

The first 2 digits are a code for the manufacturing plant.  

The next 2 digits are a code for the tire size.  

The next 3 or 4 digits are a code for the type of tire.  

The last 3 or 4 digits are the date code.  The format is week/week/year/year or week/week/year.  These are always numbers.

Starting in the year 2000, the date coding used was 4 digits.  That means the largest number you should see for the year is 09.  Before 1999 the format was 3 digits.  1999 and 2000 are transition years, so you will find both 3 and 4 digits.

The date code only has to be on one side – and it is permissible for there to be a partial DOT code, so long as one side has the complete code.


---------- FOLLOW-UP ----------

QUESTION: Live in Manitoba Canada so there should be no issues with age.... bought tires 3 yrs ago.... new except for inside edges.

Is there any sense in rotating tires on a single axle trailer? Simple side to side or flip them inside out to keep rotation the same?? ie radial memory?

Answer
Bill,

I think you should do a complete reversal - both inside becomes outside and side to side to even out things.

And as far as "Radial Memory" goes.  Until yesterday, I had never heard the term.  When I looked it up on the AllExperts web site, I see where John had used it about 2 1/2 years ago.  I think he was trying to describe a phenomenon that I would call irregular wear.

So, no, I don't think radial tires have a memory, but I do think they can wear irregularly, and misalignment is one of the major causes.