2009G37

iTrader: (1)

Hey guys,
I know that if you're gonna keep gas in the tank for a while, you should add stabilizer. So how long is "long"? Suppose you have a Lambo that you drive once a week and a full tank of gas lasts you like 3 months or something. I mean, should you add stabilizer basically on every fill? I don't have a Lambo, just saying.

Also, why is it bad to not keep your tank relatively full? I've heard that keeping it full prevents condensation from forming in the tank, but again, for say the Lambo, the tank is going to be half empty for like 2 months. Is this too long? How low should you let the gas volume go before you fill her up to full again?

Sorry if these questions seem simple....

G37Sam

I deleted the other thread because it was a repost. Please stick to this one and bump it if you have to (not every hour though)

I wouldn't bee too **** about it, if you're driving your car every 1-2 weeks you should be fine without the stabilizer. Stabilizers are usually added when cars are to be stored for a peroid of months etc.. (winter)

RedG37SNC

Wow, if I was only able to drive my Lambo or G once a week, I'd need the stabalizer...

2009G37

iTrader: (1)

Really? But why would driving it every 1-2 weeks prevent the gas from going stale? I mean,the gas that's in the tank is just still sitting there right? I've read that over time, the gas will oxidize and then leave gunk in the engine/injector..etc. I guess what I was hoping to find out was the shelf life of gas. How long can you leave it in the tank and still feel safe knowing it won't leave crap in your engine? I live pretty close to work, and although I drive almost daily, a half tank lasts me like 30 days. I mean, this is getting kinda long isn't it????

Black Betty

iTrader: (60)

Fuel stabilizer is only needed for fuel sitting for very long periods of time without ever being driver (a month or more). It doesn't matter if a tank lasts you for a month if you drive it every day or few days. Just like you would use stabilizer in a lawn mower or chain saw stored over the winter (if you leave gas in it) but not when you use it every 2 weeks to cut your grass.

There is no issue whatsoever from filling your tank only half way if it takes you a very long time to burn it off.

2009G37

iTrader: (1)

Thx, that's comforting to know. I've had this car for almost a year now, and I was concerned that I may have let crap build up in the engine by taking several weeks to go through a tank of gas. I've googled this topic, and as usual, opinions seem to be divided. The other issue I've heard is that you should let your tank go too empty, because then the fuel pump heats up and may wear out prematurely....

So if you drive every couple of days, does the gas in the tank not go stale because it's being moved around or something? I mean, how does driving prevent oxidation of the stuff in the tank, which for the most part, hasn't really gone anywhere?

Black Betty

iTrader: (60)

I've personally never heard anything like that at all about the fuel pump heating up. Your fuel pump will pump normally as long as it's got fuel pumping through it and doesn't pump completely dry. Gas will lose a bit of it's octane if it's allowed to sit in an open container for a long period although it will still burn. Your fuel system is a completely closed system. I can't see how any outside contaminants could be introduced into the system. Yes, gasoline will degrade chemically over time, and there are a million differing opinions on how long that takes (some say a week, some say years). I can't see it happening in a couple of weeks time from my knowledge of petrochemicals and personal experience with cars. If it makes you feel better, fill up with 3 gallons every week if it gives you peace of mind.

2009G37

iTrader: (1)

Well, I only found out about this like this week, and prior to this, I've never given stale gas any thought, and I've never had any troubles. So I suspect you're probably right.

The explanation I've read about the fuel pump is that it actually uses the gas its submerged in to keep it cool, and less gas equals less heat sink, and more wear. Again, I have no idea if that's true or not, just what seems to be on the net!

May I ask about your opinion on winter storage? Is gas stabilizer really worth it? I mean, are we trying to prevent gas from going bad, when it actually never does in the short few months we store the car in winter? If you had to store a car for say 4-5 months of winter (I'm in Canada), what would you consider prudent action?

todd92

Gas stabilizer is great stuff. Do you need it? Weeks, no. Months, yes.

BradManUWF

Stabil is not expensive and here's a link that should answer most of your questions:
Sta-Bil FAQs

Black Betty

iTrader: (60)

If I were to store my car for winter, personally I would run it very low on gas, almost empty (to where the distance to Empty reads ----) so there is only a very small amount of gas left in the tank. Then I'd drive to the nearest station (within a mile or 2 hopefully) and fill up when I brought it out of storage.

However, the previous 2 posters are right on the money IMO - some Sta-bil in your tank is a good idea for months of storage if you will be storing it with fuel in the tank.

BradManUWF

That is actually one of the worst things you can do, especially if you've got E10 fuel in your tank. I don't know if our tanks are plastic or metal, I assume plastic. But as I found out with motorcycle tanks, low fuel level and a metal tank don't mix well. Rust covers the inside from condensation forming in the tank because there isn't enough fuel/vapor to displace the air. If you're using E10, which most states are now, the ethanol will absorb the water that forms in the tank and sink to the bottom....where the fuel pick-up is. Engines don't run too well when using water as fuel. If you're going to put it in storage. Fill it up, add Sta-Bil, and it will be fine. Either that or drain the whole tank completely and spray it with a lubricant to prevent rust. Filling up and adding a stabilizer is much easier.

2009G37

iTrader: (1)

But wait, earlier it was mentioned that the tank was a closed system and that air can't really get in/out. So, if you have a full tank, and then use up some gas, shouldn't the space created just be filled with gas vapour? How would air with water vapor get in?

BradManUWF

The tank has to vent and equalize pressure somehow. It's not going to create a vaccum because that would reduce fuel pump effiency.

Is this the "Closed System" you're talking about?

In order to meet stricter emissions requirements, catalytic converters were introduced. Very careful control of the air-to-fuel ratio was required for the catalytic converter to be effective. Oxygen sensors monitor the amount of oxygen in the exhaust, and the engine control unit (ECU) uses this information to adjust the air-to-fuel ratio in real-time. This is called closed loop control -- it was not feasible to achieve this control with carburetors.

2009G37

iTrader: (1)

Ah, learning every day. So if there's water at the bottom, and this gets into the engine, does this actually damage the engine in some way, or just makes it less efficient or decrease hp? I mean, none of us are ever driving around with an absolutely full tank all the time. If you fill up say every 2 weeks, then presumably, for a week, you're on half a tank or less. So isn't there always some condensation and water getting to the cylinders? Should I keep my tank full like all the time?