Diesel fuel stabilizer for winter layup

[Capt Robbie]

Had a full tank of fuel at end of season and I added stabizer last year before winter layup as I have always done for years.
This year still have the same full tank of fuel from last season maybe used about two gallons this year. Not enough to top off.

Question ???
1) Should I add more stabizer to the fuel before winter layup or is the stabizer I added last year enough?
2) Does stabizer become less effective over time?
3) Can you over stabize deisel fuel if I add more?

Fuel amount I am dealing with is about 18 gallons.
Used sea foam stabizer

I have asked 10 local yanmar marine dealers and have got conflicting answers.
Half say to stabilize the fule and the other half say don't.

I normally don't have an issue with fuel because I rarely ever have this much unused fuel at the end of the season.

Any feedback would be great

 

[Tally Ho]

I used about 1/2 of the diesel in my 18 gal tank this year.
I added stabilizer last year, and about 5 gal of fuel when I hauled out.
I plan to add some additional stabilizer. I don't think a refresh of the stabilizer will hurt.

Otherwise, I guess you could drain the tank into Jerry cans (not sure what you want to do with it after that).

And most importantly, use that boat more next season!

Greg

 

[SailormanDan]

I think those little bottles treat 350 gallons, I'm sure I've added too much over the years and not had issues. At 1/3 of a gallon an hour, if I top off every year it takes me years to use up a tankful, so I don't agonize over it, just don't run it empty.
What broke my engine after 35 years was not sludge from the tank, but the ring on the cylinder breaking.

 

[jssailem]

Robbie,
Most of the stabilizers are not upset if you add more than specified. I have used a blend of Star Tron/Biobor JF for diesel fuel. These deal with the corrosion and the biologic intruders that can contaminate your fuel.