I just bought a 1990 Triton 2 horse slant load trailer in excellent used condition.  The tires look to be newer and in great shape, but I know looks can be deceiving.  I understand you can date tires by looking at the DOT tire identification number but am having trouble understanding if I am reading them correctly.  Are they different for trailer tires vs. passenger car tires?

One reads DOT K9NV11001

One reads DOT 5YNV1106

Two of the tires read DOT K9NV07001

So if I am understanding these codes correctly, one tire was manufactured in the 10th week of 2001, one was manufactured in the 11th week of 2006 but the other two are what's throwing me....70th week of 2001?  That makes no sense to me whatsoever.

If anyone can help, I would greatly appreciate it.  I will most likely get new tires all around soon anyway, but I am on a pretty tight budget so if I can wait a little bit, that would be great.  But I also don't want to be using a trailer with tires that are potentially dangerous.  I mean, they looks great and the trailer hauled home beautifully, but....?

Thanks!!!

DOT Number

All tires sold in USA must have the "DOT" ((Department of Transportation), or tire identification number, moulded into the sidewall. Our tire has a DOT number of GHYT 4501. The first two characters after DOT indicate the manufacturer; the second two characters indicate the plant where the tire was manufactured.

Next you may see an optional string of three to four characters. Our example does not include this code. Most manufacturers use these to record company specific information about the tire, and, if necessary, use them as a guide when issuing product recalls. Because they are company specific, these codes are not standardized and are meaningful only to the manufacturer.

The last three or four digits give the date the tire was made. For all tires built after 1999, this will be a four-digit number with the first two digits giving the week number, and the last two giving the year. For many tires built previous to 2000, the date indicator will consist of three digits, the first two giving the week number and the last giving the last digit of the year. In our example tire, the last four digits of the DOT code are 4501, so our tire was made during the 45th week of 2001.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=11

So why do two of the tires have 7001 as the last four digits?  There are not 70 weeks in a year!???

Because it probably reads 0701.... I think you got too many zeros in there.... They are four digit numbers, in your first post you listed the number as..."07001" My guess it reads 0701.

Anyway, it looks like one tire might be OK. If in doubt, replace them all , then you'll know what you got. After 5 to 6 years mine get replaced.

DITTO

I triple checked.  The number stamped on the tires after the DOT part reads 07001...

Well, in any case, looks like I need new tires anyway.  I will probably keep the '06 one as the spare and get four new ones.  Any suggestions as to a good place to get a great deal on trailer tires in the Portland, OR area?

Thanks!

 wyndancer..... Re-read what I posted.... I said one tire may be OK.... That being the one with the 06 date... (3 years old) Not the 01's... What did you think I meant...?

Well, those K9 tires are from Taiwan, so who knows what they were thinking...

You may want to peruse this article so you can understand how companies will do anything to avoid the customer becoming knowledgeable...

http://www.safetyresearch.net/Library/Recalls_RFID.pdf

Thanks for that link Paul, makes for some interesting reading...