For those who store their boat for the winter more than 90 days, do you top off the tank before putting into storage? Generally my 80 gallon tank is about 1/4 at the end of the season and I rarely have topped off in past years due to other end of season expenses like winterizing, storage and future slip fees. Perhaps this is being pennywise and pound foolish?

What say you?

I usually try to burn as much as possible towards the end of the year.

i've read numerous posts across numerous forums on this topic and have yet to find a definitive "best" practice. in most cases, the consensus seemed to be it's OK either way, as long as a good stabilizer is used before the boat is stored.

We are lucky to have ethanol free premium at the marina so I do top off the tank and do use fuel stabilizer.

Merc says that if you use fuel with ethanol, so leave the tank as low as possible.

Tank empty/full is almost like opening up a debate on what kind of oil you use!

Yep, top it off and add Stabil Marine Formula before winter lay-up.

I actually have been using Stabile during the season in every tank too.

Nope and I don't think it matters either way.

I normally do, I think I am pretty full already however I did not top off this year. The boat is already tucked in the garage and will remain that way until April 2009. I have stabil in. Still need to pull the battery and put it on the charger.

I asked my mechanic (both MC + Volvo authorized) that very question just last week. He said it does not matter if you are using non-ethanol gas + Stabil (which we do).

I do not top off the tank. The past 2 seasons, I have used one full tank (~40 gallons) of gas each year. I always have sta-bil on hand, and if I add gas, I add sta-bil, so whatever's in the tank is protected.

I might reconsider this method if I kept my boat outdoors for storage, but it's in my heated garage year-round. I see the risk as minimal, considering the conditions.

Whatever's in the tank is what stays over the winter. And for the last 2 years I've bought all my boat gas the end of February when it's been the cheapest. I think they oxygenate it, but I'm pretty sure there's no ethanol in it. Whatever it is, my boat's don't seem to care.

2 weeks ago I drained about 18 gallons of gas out of the party cruiser that's been there since the summer we got it, in 2005. I've never added Stabil to it, and there was not a thing wrong with it. Looked and smelled like the new gas I had in another can. The engine fired just fine too. I just put the gas in my car & truck. There's about 10 gallons still in the generator tank, the genny fires up just fine too, so I'm just going to leave it there.

I would say yes because that is what my teacher told me in boat school. He said the reason to top it off is that way there is less chance of condensation build up in the tank when the temp fluxuates but regardless of full or not always put in stabil.

I always fill it to the top before storage and use stabil. The less air that's in there, the better.

96 gallon tank . . . I leave it empty over the winter.

Right now it has about 10 gallons in it. I may just leave it.

I fill mine close to full before storage and add stabilizer. The return on that full tank of gas by spring will be better than investing in the stock market.

I've stored it every way possible, full, 3/4, 1/2, 1/4, nearly empty, and it's never made any difference. I add the appropriate amount of Stabil and I have never had ANY fuel related isses.

I may fill it up some this year, as gas prices are lower now than they will be in March/April when I get it back out, I'm sure!

I add the right amount of Stabil every time I add fuel, so I don't worry about stabilization. As to full/empty, right now gas is below $3.00 again. I don't know what it'll be in the spring but I've got a good idea. So "as full as I can get it" for me.

Did the same thing last year. A good part of this summer, the boat was burning $2.85 gas.

What's it mean to 'store' your boat? That does not compute.

I do fill mine before the really cold weather hits and add Stabil to it, but I use it throughout the winter. About once a month we'll take it out and put a few hours on it just to charge up the batteries and keep things lubed.

^^^^^^

I concur.

I've never had to deal with it.

We boat year-round, so it's not an issue for us.

FWIW, I've always been told by folks "in the know" to leave the tanks full while in storage due to the possible condensation build-up.

I do put water-zorb in the tanks on a regular basis though.

Just in case...

For the past three years gas has been much cheaper in October when I store than in May when I start my season therefore I always top up before I store it.

I also subscribe to the idea of less air in the tank reduces the chance of condensation.

I leave mine as empty as possible, as I don't want the extra weight of fuel sitting in the boat all winter long. More important to me is using sta-bil, and running the engine with stab-bil treated fuel to reduce the chance of gumming in the fuel system before winter lay-up. A quick treatment of water-eater on the first tank in the spring takes care of any possible condensation.

We add stabil the last couple fill ups and then leave boat fairly low on fuel. Have owned a boat for 19 years and have never had any fuel related problems. Boat is stored indoors in an unheated building most of the year except when being used.

Ok, so who HAS ever had a problem with gas? From our little unscientific survey here, it seems to be a non-issue...(aka worrying about nothing)

My buddy has a 97' SeaRay with a 5.7 carbed Merc Alpha one. Low hours and well taken care of. Couple of years ago he was getting a pinging under load, quickly the pinging got worse and I was with him when the motor made a horrible pinging noise and died. Time for a new motor. Everybody he talked to said it probably started as a fuel related issue. Either bad gas (old) or water in it.

I suppose we'll never know for sure what the root cause was but this was enough to scare me into paying attention to what's in my gas tank.

I do normally top off the tank although last year I didn't because the tank was already pretty full. My dealker advised me to top off the tank before storing all winter. I think that it's supposed to help keep condensation from forming on the inside of the tank surfaces. Less condensation is good.

I put about 3/4 full with Star-tron for 4 years with no issues on our old carbed 3.0L and new 4.3MPI
Star-tron during the season around August and there on out

I have always tried to fill the tank prior to storage. As TEG has stated it seems gas is cheaper in the fall then in the spring when the boat comes out of storage for the summer.

It means waking up early next Saturday morning, hooking up the boat and driving to the storage facility, unhooking and not seeing my boat until next April.

I store it full, with StaBil.