Tire data can sometime be confusing and there are many "experts" on the forums who base wieght carrying solely on the letter.
Not all "E" tires are the same and may not be able to carry the same weight.Check out this article:
Load Range and Load IndexThe old way of determining load capacity by a "letter" (D, E , F, G) connotation is not really valid as much as it used to be but it is important because the letter relates (among other things) to what the tires maximum PSI can handle and Load Index (LI) relates to weight carrying capacity.
LI is the actual weight the tire can handle at the max PSI. So the two go hand-in-hand. Look at both when selecting a tire.