I am not a trailer tire salesman, nor a trailer salesman, nor a tire salesman.....
just Googling your trailer tire size...ETrailer had this info:
What is Correct Tire Pressure for a 4.80-12 Size Americana Trailer Tire on a Viking Pop Up Camper | etrailer.com
What is Correct Tire Pressure for a 4.80-12 Size Americana Trailer Tire on a Viking Pop Up Camper
Question:
I have a viking pop up camper epic 1906 Model 510 that has 4.8-12 americana tires on it. What should the tire pressure be ?
asked by: Bill
Expert Reply:
The amount of tire pressure you need in your 4.80-12 Americana tires depends on the load range of the tire.
If it is a load range B, it will need to be at 65 psi like # AM10060.
If it is a load range C, it will need to be at 90 psi like # AM10062.
The trailer tire should state what load range it is on the side wall. Trailer tires should be inflated to their max psi rating listed on the tire sidewall for best performance and longevity.
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This may have greatly confused your expected results.
If you don't get a definitive answer.....by all means, take your trailer by a reputable tire dealer and have them look and help you out so you get it right. With a guess, you have a 50% chance of being right and a 50% chance of being wrong. Your personal safety and the safety of those you are driving in close proximity to means you need to get it right.
Good luck and let us know what you find out.
ps-the date of manufacture of your tires will be on the sidewall, too. If your tires are old and cracking and splitting, you may need new tires and valve stems. Be careful.