Why store with a full tank of fuel?

[Speedy!]

I've seen several of you post that when you store your car, you top off the tank with fuel. The fuel tank is plastic, so I wouldn't think topping it up is needed unless you guys worry about condensation some how? I'd wonder if the fuel is still any good after storage for 5 or 6 months?

I normally drive mine at least once a month, but we've had terrible weather lately and I'm wondering how long I can wait before getting it out for a drive.

 

[jroyk]

I've seen several of you post that when you store your car, you top off the tank with fuel. The fuel tank is plastic, so I wouldn't think topping it up is needed unless you guys worry about condensation some how? I'd wonder if the fuel is still any good after storage for 5 or 6 months?

I normally drive mine at least once a month, but we've had terrible weather lately and I'm wondering how long I can wait before getting it out for a drive.

I’ve always topped it off because of condensation, but that might not even be a concern these days with ethanol in the gas. I also add Stabil to the last fill up and the gas seems just fine in the spring. BTW and FWIW, Project Farm did a seemingly valid test of fuel stabilizers and Stabil was a clear winner.

 

[Speedy!]

I did put some Stabil in the tank last 93 fill up - but I typically only keep 1/2 tank in the car as I never know when I'll wanna go from 93 to E85 or back again.

 

[jroyk]

 

[drag racer]

personally, 6 month old modern gas causes me zero concerns, and is actually quite "new" in my world

 

[jgilj]

I went for a little ride today 37 but beautiful blue skies.

 

[2ndAmend]

I have been messing with engines since the mid 60's, never had a problem, even here up north. I mostly don't worry about it. I do drain the carbs in my lawn mower and wood splitter. And I don't race the cars until the old fuel is burned up. Hope everything will start next spring!

 

[2ndAmend]

But if I had to think about it, I would leave the tank near empty and let the ethanol soak up the condensation, then run the tank empty in the spring, then start fresh.

 

[jroyk]

I have been messing with engines since the mid 60's, never had a problem, even here up north. I mostly don't worry about it. I do drain the carbs in my lawn mower and wood splitter. And I don't race the cars until the old fuel is burned up. Hope everything will start next spring!

Since switching to E0 and Stabil, I don’t even bother draining float bowls in my outdoor power equipment anymore. Everything starts right up in the spring.

 

[BULL]

I've always heard that it's about air volume which in turn equals amount of condensation.


If the available volume of air is minimized, so is the condensation.


Reality? Who knows...

 

[Jack_Toepfer]

and the parts most impacted by condensation in your tank are at the top, most exposed to it.

 

[1971demon]

I've seen several of you post that when you store your car, you top off the tank with fuel. The fuel tank is plastic, so I wouldn't think topping it up is needed unless you guys worry about condensation some how? I'd wonder if the fuel is still any good after storage for 5 or 6 months?

I normally drive mine at least once a month, but we've had terrible weather lately and I'm wondering how long I can wait before getting it out for a drive.

5/6 months...it will run I wouldn't beat on it.

 

[B5Cat16]

Full tank of 93 with Sta-bil MARINE and a small bottle of dry gas. I do this in all my cars. Never had a problem.

 

[jgilj]

A wise man told me always said cut the grass short and fill the tank on your car full ! I always do. Been doing it for 60 years probably not going to change.

 

[45-70govt]

Speaking from the aviation world, after every flight almost all pilots fill the fuel tanks to prevent moisture from accumulating in the tank. Before every flight there are several drains in the fuel system that we check for water. When the tanks are left full its unlikely to see any water in the bottom of the fuel sample. I did a BFR flight for a guy with a 182 that sat for months with the tanks maybe 1/2 full. When we checked the fuel drains each had a fair amount of water come out.

My Hellcat is driven far less than even occasionally. Because it sits untouched for so long I keep the tank full of non ethanol Torco storage fuel. A guy at work swears by it, so I decided to give it a try. Honestly don't know why it would be better than any other non ethanol fuel, but its what I use. The last time I drove the car it had sat for just over 2 years since it ran last. With the storage fuel I had no issues and it started just like it was shutdown the day before. With fuel that old I would burn it all off before getting on the car hard at all though.

https://torcoracefuel.net/products/...AXerN2KWVzoFESR57QN2oqW3wYHuexfCywLZq5337XRs_

 

[Speedy!]

Thanks @45-70govt that's really what I was looking for some real world examples of "here's why". The water in the 1/2 tank scenario is compelling. Are plane tanks some kind of metal alloy like aluminum or steel or are they plastic like our cars? I wonder if that has an impact on water collection.

 

[BULL]

Speaking from the aviation world, after every flight almost all pilots fill the fuel tanks to prevent moisture from accumulating in the tank. Before every flight there are several drains in the fuel system that we check for water. When the tanks are left full its unlikely to see any water in the bottom of the fuel sample. I did a BFR flight for a guy with a 182 that sat for months with the tanks maybe 1/2 full. When we checked the fuel drains each had a fair amount of water come out.

My Hellcat is driven far less than even occasionally. Because it sits untouched for so long I keep the tank full of non ethanol Torco storage fuel. A guy at work swears by it, so I decided to give it a try. Honestly don't know why it would be better than any other non ethanol fuel, but its what I use. The last time I drove the car it had sat for just over 2 years since it ran last. With the storage fuel I had no issues and it started just like it was shutdown the day before. With fuel that old I would burn it all off before getting on the car hard at all though.

https://torcoracefuel.net/products/...AXerN2KWVzoFESR57QN2oqW3wYHuexfCywLZq5337XRs_

Jesus, I didn't even think about taking fuel samples...




Every have a poppet valve stick open...?


600gallons of JP-5 all over the flightline...

 

[1971demon]

Thanks @45-70govt that's really what I was looking for some real world examples of "here's why". The water in the 1/2 tank scenario is compelling. Are plane tanks some kind of metal alloy like aluminum or steel or are they plastic like our cars? I wonder if that has an impact on water collection.

The greatest contributor to condensation...is variable temperatures....all mine are stored @ 65*..and 50% humidity...all year round...with stabilized fuel...even when stored all year long..@ less than a quarter of a tank...my 18 Demon's fuel will still maintain 100 octane in the spring...top them all off with fresh fuel every spring..

 

[45-70govt]

Thanks @45-70govt that's really what I was looking for some real world examples of "here's why". The water in the 1/2 tank scenario is compelling. Are plane tanks some kind of metal alloy like aluminum or steel or are they plastic like our cars? I wonder if that has an impact on water collection.

Most light aircraft tanks are aluminum. Some are known as a wet wing where a cavity in the wing is sealed and used as the tank. Others use a rubber bladder in the structure to make the tank. Some home builds and ultralights use plastic tanks. My plane uses the hollow aluminum wing spar as the fuel tank.

With aircraft the concern is not as much about corrosion of the fuel system as it is about water getting to the carburetor at a very inconvenient time like just at rotation on takeoff for example. I don't think tank material has much to do with the condensation settling out. Its just the amount of atmosphere and water content that settles out at night once the temperature drops. Less room for moist air in the tank, and less chance of water collection in the bottom of the tank.

On the example where we got water out of the tanks I bet that altogether we drained close to a 1/2 tester jar worth of water out of all the drain points combined. Don't know how many oz. of water that would be, but the below pic will give you an idea. Keep in mind this was on a plane that lives in a hanger (no rain) and in the middle of super dry air New Mexico.

 

[Jack_Toepfer]

The only ethanol free around me is 90oct, so filling up with that would make for a less enjoyable first outing in the spring, unless you top it off with some octane booster too.