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Tireman9 · 07-27-2021, 01:04 PM

Some comments on DOT date code.
re "oval" Tire mfg use different methods of changing the aluminum"plug" in their molds for the "date code". Not all use an oval plug. Some have used stamped steel strip or "tin" so it can have a different appearance.

Some things that are true about all DOT serials.

The code comes AFTER the symbol DOT by law
The first 2 characters are a plant code. the next 2 are a size code.

The last 4 numbers are the date code.
The serial may have as few as 8 characters and as many as 13 with most having 12 or 13.
The date part of the serial only is required on ONE SIDE so may not be on the curb side but facing in toward the coach.

My advice is to find the code and record it when it is convenient to you. Nice weather day. If needed i have suggested a $5 or $10 bill and a flashlight and a 10 year old to crawl under the coach or trailer if needed.
Remember you may need to "roll" the RV forward or back a few feet to get the serial in a position that the 10 year old can see it.

Keep the full serial with your other important part numbers as you never know when you will need this information.

07-27-2021, 01:04 PM	#1
Tireman9 Senior Member Join Date: Sep 2018 Location: Akron Posts: 458	DOT serial date Some comments on DOT date code. re "oval" Tire mfg use different methods of changing the aluminum"plug" in their molds for the "date code". Not all use an oval plug. Some have used stamped steel strip or "tin" so it can have a different appearance. Some things that are true about all DOT serials. The code comes AFTER the symbol DOT by law The first 2 characters are a plant code. the next 2 are a size code. The last 4 numbers are the date code. The serial may have as few as 8 characters and as many as 13 with most having 12 or 13. The date part of the serial only is required on ONE SIDE so may not be on the curb side but facing in toward the coach. My advice is to find the code and record it when it is convenient to you. Nice weather day. If needed i have suggested a $5 or $10 bill and a flashlight and a 10 year old to crawl under the coach or trailer if needed. Remember you may need to "roll" the RV forward or back a few feet to get the serial in a position that the 10 year old can see it. Keep the full serial with your other important part numbers as you never know when you will need this information. __________________ Retired Tire Design Engineer (40 years). Serve on FMCA Tech Advisory Committee. Write a blog RV Tire Safety. Read THIS post on Why Tires Fail.