Tire question: Load Range

Shopping for trailer tires, and I’m confused about load ranges. Several tire sites claim an “E” rated tire can handle 1520 lbs. The folks at the tire store say the E rated tire is sufficient for both my 10,000 and 8000 lb. trailers, but the math doesn’t add up. 1520 X 4 is only 6000 lbs. The tire store says I can actually manage the 8K trailer on D-rated tires. A new trailer we’re considering weighs 13,000 lbs., yet comes with E rated tires as well.

What gives? Is there some type of cumulative ability here where the total exceeds the sum of the parts? I’ve always assumed the tire store was the authority, and every one I’ve dealt with claims the Es are enough.

I think you have to factor in tire size and load index as well.

1520 lbs seems very low for an E tire unless it’s quite small.

Thank you. I figured there was another factor involved. I just hadn’t worried too much, as I always put E’s on all my stuff.