Oil stats: Filled: 9/21/2012 - $3.389 gallon $833.02 (245 gallons) Usage: 9/21-11/26 = 67 days 3.36 gallons per day = $11.49 per day Filled: 11/27/2012 - $3.419 gallon $772.00 (225 gallons) Usage: 11/27-1/6 = 41 days 5.9 gallons per day = $20.59 per day VC Merrimack installed 12/20 Filled: 1/7/2013 - $3.489 gallon $843.29 (242 gallons) Usage: 1/7-2/27 = 52 days 4.76 gallons per day = $16.64 per day Filled 2/28/2013 - $3.489 gallon $867.37 (248 gallons) Fireplace Insert was installed 12/20/2012. VC Merrimack. Insert shows a savings of $4/per day in oil heating costs. However, wood costs over that same period of 69 days of burning wood were $7.25 per day, resulting in a net cost increase of $3.30 per day than using oil alone. To be fair, it was mild before the fireplace insert was installed and was extremely cold this Winter for a good stretch. First year in this house, so I guess I really don't know how much oil I would have used in the dead of winter. House is 4200 sq/ft built in 2000. Disappointing results for me. I burned 24x7.