I calculated savings in that my electric bill went down 30 $ and my gas
went up 6-7 $ .
This was removing an efficient Rheem 40 gal electric tank 4 yrs old ,
that was "Energyguide " rated at 420$ a yr at 0.8 KWH. And I had a
Fiberglass insulating blanket on it in a heated basement. I replaced it
with Battery ignition Bosch Aquastar .

BTW for all naysayers the Bosch is rated on " Energyguide " at
188 therms a year or 130 $ It is the THE model that uses the Least
energy by " Energyguide".

My Top quality efficient Rheem rated 420$ a year at .08 or 4992
kwh. At my 0.12 that is 599.04 . The Aquastar rated 188 therm or apx
180 $ at todays prices. There showing a savings of apx. 69% by
government tests not my estimates.

I also find myself more aware of my water heater using cold water more
often.