I just started testing using additive in the home heating fuel to increase the BTU level and to cut down usage of burning the oil to fast.

I have 2x 250 gallon tanks 500 gallons — Since oil is so expensive I have cut back to 1 tank for now to run my test. I’ve started my test since Nov 2007.

For each 100 gallons of home heating oil I’ve added 1 quart 32 oz of Marvel Mystery Oil $3.29 to $3.99
16 oz of Marvel Mystery Oil $2.69 to $3.29

I’ve poured 2 quarts and 16 oz for 250 gallon tank.
As soon as I have poured the MMO into the tank the house gets hotter quicker.

I’ve tested without using it and the house feels cold. I use a Honeywell 7-day electronic computerize themostat to keep it at the temp I want.

M-F
Wake at 70F - 7:15a
Leave at 65F - 8:15a
Return at 73F - 6:30p
Sleep at 65F - 12:30a

Weekends is about the same except for the temp.

I also have a newer steam boiler with energy star. But I always felt the house wasn’t hot enough. I also get hot water from the boiler too. So you see with MMO the family room in our basement is really hot with MMO about 78F. I have a lot of those steam pipes down there.

Well I just had to fill the tank with oil two days ago, but the tank is able to last with the settings above about on average with MMO in the tank:

1.3 months on 250 gallon tank with every day being cold from 18F to 30F..

1 month 3 weeks

2x tanks would last me 3.2 months

I am sure some here keep the house cooler, I just can’t live like that it has to be a certain temp if I am home in the day. At night it has to be 65F. You don’ really want to go lower than that otherwise you’ll start to have plumbling problems with the house being to way to cold.