Storing Vette for winter, full tank or empty tank?

[Patman]

I know I've heard many automotive experts recommend storing cars with full tanks of gas in them, but that started a long time ago and I would imagine the modern tanks aren't even made out of metal anymore. So therefore rust is a non issue, and I really shouldn't worry about condensation right? The car will be stored in my single garage, which isn't heated but since I'm in a townhouse the garage has no open sides (except the front door obviously) and stays pretty warm and dry (the door won't be opened during the storage period unless I get some nice weather and am able to drive it) So am I safe to store my Corvette this winter with very little fuel in the tank? My reasoning is that gas loses octane as it ages, and my full tank of 91 octane could end up being lower than 87 octane by the time spring hits. I would much rather pull it out in the spring and immediately fill it with fresh fuel, as opposed to having to run through a whole bunch of old fuel first. Or should I just split the difference and store it with a half tank of gas?

 

[mva]

My vote is for a full tank. I store my Z3 and lawnmower over the winter with a full tank of gas with the recommended amount of marine Stabil mixed in. The logic is - as the tank goes through temperature changes in storage any unfilled space will tend to breath. Breath out warm, breath in cold. Moisture in the air that is inhaled will accumulate in the tank. Smaller airspace equals smaller breaths.

 

[Rand]

I'd fill it full and put double the stabil dose in it.

 

[eljefino]

I like the way you think. Cars are so tight these days in the fuel system with vapor canisters and what not, I don't see moisture getting in and being an issue. Yeah, it can screw up your lawnmower leaving it that way. But it has a hole drilled in its tank cap! Totally different animal. I would worry about losing volatility, but it's late enough in the fall you're getting stuff with a good RVP. And a sports car with huge injectors and lots of surplus power will run on anything until it gets fresh fuel.

 

[LargeCarManX2]

I would store it with a full tank and fuel additive for storage. But a gas fill up could be close to 100 bucks. So second choice would be 1/4 tank with fuel additive and in the Spring add water remover such as Heat red bottle.

 

[daves87rs]

Filled and some stabil should be fine. I usually drop some higher octane gas in mine for the winter, still it still pops out every now and then...

 

[hate2work]

Store it with a full tank filled with non ethanol gas, along with some star-tron fuel stabilizer. Put a battery tender on it, put it up on jack stands to prevent flat spotted tires, don't engage the parking brake, and put something in your tailpipe to keep the critters out.

 

[Bluestream]

Originally Posted By: Patman

So am I safe to store my Corvette this winter with very little fuel in the tank? My reasoning is that gas loses octane as it ages, and my full tank of 91 octane could end up being lower than 87 octane by the time spring hits.

Store it with a full tank!! 91 octane gas in Ontario is Ethanol free and can be stored up to one year with no loss of octane, or using ant stabilizer

 

[Patman]

Originally Posted By: mva

The logic is - as the tank goes through temperature changes in storage any unfilled space will tend to breath. Breath out warm, breath in cold. Moisture in the air that is inhaled will accumulate in the tank. Smaller airspace equals smaller breaths.

But what harm will that moisture do if the tank is not made of metal? It's not like it's going to form rust, and I don't think it's going to be such a large amount of moisture that it would taint the fuel would it? I also don't think the temperature changes in the garage will be all that drastic, it should stay pretty consistent all winter long, probably ranging from about 40F to 50F and not much above or below that.

 

[Patman]

Originally Posted By: LargeCarManX2

I would store it with a full tank and fuel additive for storage. But a gas fill up could be close to 100 bucks.

That's another reason I'd rather not totally fill it! At the current price for gas here, it will cost me about $90 to completely fill my tank if it's almost empty. I know I'm going to spend that money on gas eventually but I hate the thought of spending it all now and then having that same gas not be 100% perfect in the spring when I bring the car out. As long as I'm not doing serious harm, I'd rather throw in $10 or $20 worth of gas now, and then in the spring I could immediately fill it up completely. Of course, I'm open to discussion here, which is why I started the thread, to see if modern cars really need to be stored with full tanks or is this just a holdover recommendation for cars made 30 years ago? PS-I do use Shell premium, which has no ethanol here. I believe they are the only one that uses no ethanol though, Esso and Petro Canada definitely put ethanol in their 91 octane.

 

[sdan27]

I'd store it with a full tank. Chances are fuel prices will go up by spring so then you'll be saving money too.

 

[needsducktape]

Originally Posted By: sdan27

I'd store it with a full tank. Chances are fuel prices will go up by spring so then you'll be saving money too.

Yes, think of it as an investment !! haha

 

[dparm]

Full with a stabilizer.

 

[Bluestream]

Originally Posted By: Patman

Of course, I'm open to discussion here, which is why I started the thread, to see if modern cars really need to be stored with full tanks or is this just a holdover recommendation for cars made 30 years ago?

Even plastic tanks will form condensation if not filled. That means water gets into your gas!

Originally Posted By: Patman

PS-I do use Shell premium, which has no ethanol here. I believe they are the only one that uses no ethanol though, Esso and Petro Canada definitely put ethanol in their 91 octane.

I don't want to argue this point, but 91 is ethanol free in this part of the world..

 

[JimPghPA]

When atmospheric pressure changes enough due to changing from high to low, or low to high pressure due to atmospheric weather systems there is a difference in pressure from the inside to the outside of any tank containing any air space. And when the temperature of any air in the tank changes there is also a increase or decrease in pressure as that air expands or contracts. Modern gas caps have two valves set to vent if the pressure difference gets too high. One valve vents inward, one valve vents outward. When these vent inward the amount of ambient air that flows inward will be directly related to the air space in the tank. And air that vents inward has moisture that can then leave the air and enter the gas. If you gas has ethanol in it the ethanol will strongly pull the moisture out of the air. When the water molecules from this moisture interact with the alcohol in the ethanol, it form acetic acid, a mild acid known as vintner. And though it is a mild acid over time it will eat metal, including the metals in you fuel metering system. You want to minimize the air space so you minimize the exchange of ambient air and the moisture it contains. Running the engine with something like RedLine SL-1 and or Sta-Bil so all films of fuel leftover on all surfaces that fuel touches have a coating containing a fuel treatment to help protect them from this reaction would be a good idea. Fuel without ethanol would be a big step in the right direction. If it were mine I would go for a full tank of the non-ethanol fuel, double dose it with Sta-Bil, and run it a few minutes to be sure the treated fuel was in the engine fuel metering system.

 

[Mr Nice]

Fill the tank and store it for the winter. Or you can loan me the car and I can drive it for a few months since there is no salts used on our roads.

 

[tomcat27]

I will be the lone outlyer here... for 25+ years I have stored boats, snowmobiles, and at any given time and any given season I have 5-6 cars in storage. I put stabil in and run the tank down as far as possible. I am more concerned with fuel injectors than I am with moisture. In the case of 2 cycle engines I drain the tank, lines, and carbs.

 

[The motor guy]

I would add marine stabil. The red stuff doesn't work well. Then fill the tank up all the way and drive it long enough to run through the system. Should be good to go. I personally don't ever let an engine sit for any longer than a month without starting.

 

[Garak]

Originally Posted By: tomcat27

I will be the lone outlyer here... for 25+ years I have stored boats, snowmobiles, and at any given time and any given season I have 5-6 cars in storage. I put stabil in and run the tank down as far as possible. I am more concerned with fuel injectors than I am with moisture. In the case of 2 cycle engines I drain the tank, lines, and carbs.

Well, you're not exactly alone. That's how I do my snowmobile - as empty as I can get it; it's a carb so no injector issues with running it dry. My yard equipment gets Stabil on fills late in the season so they're at least protected when they sit. For a car, however, my vote would be with a full tank. However, I'd consider running some Stabil through it as more important than whether or not it's full or empty. I'd be uncertain, too. One doesn't want moisture in a mostly empty tank. One also doesn't want a tankful of premium degrading (even with Stabil) all winter, either.

 

[quint]

Put some Stabil in it, fill it up, drive it home and park it and be done with it until spring. The six months or so it will be parked is nothing to be concerned about. Earlier in life I sold cars, and some of them sat on the lot for 6-8 months before being sold or moved to another dealer, with the same 3-4 gallons the factory put in. Many of them had weak batteries after sitting motionless that long, but once jumped they ran great. I doubt the factory used a fuel stabilizer, I know we certainly didnt add any. Earlier this spring I pulled my boat out of storage where it had been for almost three years. It was put away with a nearly full tank and one bottle of Stabil in August of 2008. By now it was down to about 1/4 tank, which is no surprise since like most boats the tank is freely vented out the back of the transom. I drained the tank, about 8 gallons left, into jugs and examined it. There was no evidence of water, no dirt, and it smelled normal. Back into the tank with it (I dont really like this boat anyway). After the third attempt it started up, the idle stabilized, and it ran fine until I ran the tank down and refilled it later that week. Not one hickup, on 3 year old gas. Not recommending anyone else do this by any stretch of the imagination, just throwing it out there.