Keeping Gas Tank Full during Winter on newer cars

[chefwong]

Is it a myth or is it still recommended on newer cars to keep the gas tank 1/2 + full during the winter to prevent the gas lines from freezing & condensation.

I usually like to run the gas down to a bit and then do a fillup.

 

[heyjay]

I still keep the fuel tank full in winter, though in summer I'll let it run down to 1/4 or less.

The electric fuel pump is in the tank. Imagine how expensive that could get if it froze!

 

[pinoy99]

Bunk. I've always run my cars/trucks until they are empty(lights on or the dial at very close to E). No freezing fuel pump, etc. IMO, this is only a problem if the gas/station has a lot of moisture in their gas to begin with. Sticking with name brand gas and station that gets a lot of volume might help.

 

[Matt_S]

Keep in mind one thing that's different about today's cars. The tanks are no longer vented directly to the atmosphere. The vent goes through a charcoal canister into the intake manifold. I'm not saying this will keep every last bit of moisture out of the tank, but it will minimize it. Myself, I don't worry about keeping the tank full, nor do I have any problems in that regard. I think the biggest worry is poorly handled gas, where water is introduced during transport or delivery.

 

[michaelc80]

For safetys sake I would never let it get below 1/2 full in the winter. Not that it makes much difference as far as freezing, etc but there is too much of a chance of something happening to let it get to the E, especially in the winter.

 

[Forkman]

quote:

---

Originally posted by pinoy99:
Bunk. I've always run my cars/trucks until they are empty(lights on or the dial at very close to E). No freezing fuel pump, etc. IMO, this is only a problem if the gas/station has a lot of moisture in their gas to begin with. Sticking with name brand gas and station that gets a lot of volume might help.

---

Please tell me you don't do this in the summer time since in many vehicles the fuel pump is designed to be cooled by the surrounding fuel in the tank. Running tanks to near empty on a regular basis (at least in the warmer months) is a very good way to shorten the life of the in-tank fuel pump.

Heck, many of the owners manuals on certain models of GM vehicles specifically caution against this practice. I do recall my 98 Grand Am had that warning in the owners manual.

 

[kev99sl]

quote:

---

Heck, many of the owners manuals on certain s of GM vehicles specifically caution against this practice. I do recall my 98 Grand Am had that warning in the owners manual.

---

And most modern cars have it set up so that "E" (or the low fuel light) really means that there's two gallons or so left in the tank. Once again, methinks we worry too much.

 

[pinoy99]

quote:

---

Originally posted by Forkman:
Please tell me you don't do this in the summer time

---

But I do, the truck has 178k+(even running out of gas once) miles no issues except the thirst for oil

. The rest of the fleet are fairly new tho but I've always done it with all the vehicles that I owned(all accumulating at least 50k miles). Only had to replace a fuel pump once (88 Mustang GT after > 150k miles).

Good point too Kev99sl; E or fuel light usually means 1/8 of the gas capacity is left so the tank is not really that dry yet.

[ December 17, 2004, 03:26 PM: Message edited by: pinoy99 ]

 

[Dr. T]

I agree. My car (94 BMW 8 series) is supposedly notorious for fuel pump failures and I have 201.5k mi. on the OE pumps.....while continually running the tank down to 2-5L / 91L before re-fueling and running out of gas twice....

I would add though, although not a myth...there is always some moisture condensation that takes place within the tank....increasing as the liquid level decreases. Only with a full tank can you have no condensation.

Also, the larger the volume of liquid, the longer it takes to freeze. However, I believe both point pertain to extreme cold only...eg. below -40C.

 

[Brian Miller_dup1]

quote:

---

For safetys sake I would never let it get below 1/2 full in the winter. Not that it makes much difference as far as freezing, etc but there is too much of a chance of something happening to let it get to the E, especially in the winter.

---

This is the only reason I have ever heard of to keep your tank full. I grew up in Kansas, out in the middle of no where. Mom and Dad always said to keep the tank full and carry a couple of blankets in the trunk.

I still do this today, even though I live in Texas. When people look in my trunk and see my ice scraper and blanket... Old habits die hard.

Brian

 

[Patman]

One of the main reasons I keep my tank full in the winter is for better traction on slippery roads.

But even in the summer I find myself topping up before it gets below a half tank. I've just heard of too many LS1 owners ruining their fuel pumps by running out of fuel just once. When I had my last LS1 powered vehicle I once ran it below 1/8th of a tank and the fuel pump got very loud for a few days.

 

[Pablo]

If you live somewhere that cold, move.

Seriously I'm with Patman. I use the fuel for traction.

 

[Audi Junkie]

Condensation can happen at all times of the year. If I had a really nice car, I'd keep it full. I am usually over 1/2 tank anyway.

 

[BlazerLT]

Always keep your tank full in the winter.

It stops condensation forming inside of the tank.

This is a no brainer.

 

[unDummy]

The last frozen fuel line issue I've worked on was someone who always kept the tank full.

What about the moisture coming from the gas station?

I run my cars empty year round. Either will sit for up to a couple of weeks, outside, in all kinds of NE weather, and I never had a moisture problem.

I think that it is more of a problem if you fill up at a "not so busy" gas station, or are a Sunday only driver. Also change your fuel filters regularly.

If you still have moisture fears, grab some bottles of isopropyl dry gas.

 

[Pablo]

It kinda depends on how much you drive the beast. Nothing wrong with running the tank down if you are constantly driving the car.

It don't matter much where you live, leaving the tank nar empty whilst she sits for months ain't too smart.

And even if you live on the equator, running out of gas never makes sense

 

[sxg6]

every so often ill run my car down to E as much as possible..for some reason i think it'll get rid of any extra crud that has accumulated at the bottom of my tank..anyone else do this or think its worthwhile?

 

[doubleshockpower]

every so often ill run my car down to E as much as possible..for some reason i think it'll get rid of any extra crud that has accumulated at the bottom of my tank..anyone else do this or think its worthwhile?

Yep, I fill up and run it down to a gallon or two so I get the benefit of lower weight..in fact you maybe best off just using the lower half of the tank all the time...in terms of fuel milage, brake linnings, clutch, tires ect...ever pick-up ten gallons of gas?...trust me it's heavy.

 

[olympic]

Condensation is only a real issue if you park your car in a heated garage. The drastic temperature changes from winter cold to room temperature a couple times a day can cause moisture to build up in the tank. So either park it full of use some gas line antifreeze with each fill.

Running the car with low fuel is hard on the pump which relies on the fuel for cooling. Even a few seconds of dry running can shorten it's life. When you have less than 1/4 tank, the fuel can slosh around enough while driving to expose the pump pickup to air. With fuel pump replacements costing $500-800, I make sure my cars are refueled before they get too low.

 

[Lumberg]

If you're that worried about condensation put in a $1 bottle of ISOPLROPYL gas-line dryer every oil change or so.

DOn't use the regular Methanol-based stuff. That causes the water to separate out with the Methanol, separate from the gas. Isopropanol creates an azeotrope with water and gas, meaning it's a homogeneous mixture, and it gets carried into and buirned off by the engine.