"Dan Listermann" wrote in message
So this is a special toilet, not something that can be retrofitted.

That's correct as far as I understand because the bowl is a little different
to accomodate the way that the water dynamic flows out differently. If
there is some retrofit kit on the market it would be easier to just install
a new toilet.

I used to have an old style gravity toilet that was built prior to the water
conservation efforts and it used several gallons per flush. Then 10 years
ago I replaced it with a new gravity toilet and I was very disappointed with
the weakness of the flush. I couldn't believe how weak it was in
comparison. So I ended up throwing it away and replacing it with a pressure
model. Since then I will never go back to a gravity unit, they are junk in
my opinion because you can't do a decent flush with less than 2 gallons of
water using gravity.