I think it depends on which method is used to state drum capacity.

DOE (Department of Energy) or IEC (International Electrotechnical Commission).

For example, a top load washer that features a 3.2 cubic-foot capacity wash basket, as measured by the DOE. In comparison, front load washers that tout a capacity of 3.7 cubic-feet, as rated by the IEC seem like they hold more. However, the wash basket itself is only 3.2 cubic-feet, the exact same size as the top loader.

The difference is the lack of the agitator taking up space. So even though it's only a 3.2 cubic-foot drum, the "usable space" is equivalent to that of a 3.7 cubic-foot drum with an agitator.

That sounds correct, the IEC capacity would be about 5.2 while the DOE capacity would be 4.5cu.ft.
LG like ALL companies changed to the DOE rating in April of this year thus the IEC rating of 5.2 changed to 4.5cu.ft DOE.

Here is the statement made by AHAM.

Here is a link that might be useful: AHAM

TY George and Nunya - that solves the mystery and now I know why. Thanks, great answers.

Impliedconsent,

Are you happy with the washer. Does it wash king size quilts without balance problems?

Thank you

Gramma - we are very happy with our washer. I went from the stinky 1999 Neptune to this LG. We do toss in our king-size comforters, but we do that maybe monthly. It will take up the whole drum. All of our other laundry ... such a breeze and no mildew smell. What a relief.

Implied,

Thank you! I'm thinking one is in our future.

I have one too, no issues with it doing king size quilts unless they are super thick, then it is too large for the washer. I can easily wash 3 sets of queen size sheets in it plus 12 pillow cases. I use the bedding cycle when i do this. Very happy with the results

Thank you gates 1. Nice to have more confirmation that this is likely to work for us - with our personal quilts and our dog blankets.