When To Tank Up?

[LexKid630]

when is the best time to tank up? Whyen the needle is below the E when the yellow light comes on? Or maybe a little before the E when you have a few tanks left....I've heard many stories how at the bottom of the tank the gas is like a tar and can be bad for the engine. Is this all true?

When do you tank up?

[ford212.809]

I will tell you like I tell my wife, DO NOT if at all possible run the needle below 1/4 tank. If you have children and one of them get sick in the middle of the night, you do not have time to stop and get gas and jeopardise their health on the way to the ER. In my opinion, you are going to have to get some anyway so get it sooner rather than later. ;)

[LexKid630]

I will tell you like I tell my wife, DO NOT if at all possible run the needle below 1/4 tank.  If you have children and one of them get sick in the middle of the night, you do not have time to stop and get gas and jeopardise their health on the way to the ER.  In my opinion, you are going to have to get some anyway so get it sooner rather than later. ;)

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that's my thought too ;)

[Booyah]

I try to not let mine get to empty, but I have taken t down to ZERO (0) showing on the display! I was seeing if it would start readig negative---but it never did

[Lexusfreak]

Around a quatrer tank or slightly below that. In the winter (in cold climates) it's not recommended to go far below 1/2 a tank due to the fuel lines freezing. B)

[jimmouse]

Around a quatrer tank or slightly below that.  In the winter (in cold climates) it's not recommended to go far below 1/2 a tank due to the fuel lines freezing.  B)

 

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Hi, Lexusfreak,

Can you educate me a little bit about the fuel lines freezing issue? I have notice mpg dropped about 2 mpg when it is cold, during the weekly 600 miles round trip to cleveland.

Thanks.

[jbarhorst2]

When there is room in your tank (less than full) water vapor contained in your tank can condense and possibly freeze during the winter months. The more you let your tank go low in the winter, the more opportunity you have to allow water vapor to enter. However, with all the additives in fuel now, this is much less likely to happen. Fuel lines froze more often before the 90's.

Your fuel is always coming from the bottom of the tank anyway, so waiting until the tank is almost empty does not really change what is at the bottom. Your fuel is constantly moving in the tank and mixing anyway.

However, there is a problem that you cause by allowing your tank to go low. Your fuel pump is cooled by the liquid fuel that it is pumping. Your fuel system is basically a loop. Your pump can deliver more fuel than your engine needs. Excess pressurized fuel is returned to the fuel tank. Pumping this fuel to the engine and back causes it to heat up slightly. The more fuel you have in your tank, the bigger buffer you have. The less fuel you have, the more it will heat up because it is making the trip more often. Heat is bad for nearly any pump. As your fuel pump gets hotter, it wears out more quickly. Keeping more fuel in your tank (more than 1/4 tank) helps to slow this wear.

Tom

[914lps]

Most cars with injectors are not to be run under about a Quarter of a tank per most of the makers. That said I have a Lexus and a Saab both with injectors. I have run them dry (one time) to find out just how much gas they hold. Saab 16.4 Gal, 91 LS 400 22.3 Gal. With no harm done, but I would not do this over and over.

As for when do I fill up. When on a road trip I start looking when I'm down to about 5 gal left. This gives me about 100 miles to find a gas station (unless I know I will be driving though a long streatch of road with no gas or only Expensive gas). When at home I never go below 1/2 a tank. It's that safty thing. If there is an emergancy I can hit the road and not have to find a gas station.

But this is me. If you want to run your car down to 1 gal eveytime nothinmg says you can't.

[LexKid630]

Most cars with injectors are not to be run under about a Quarter of a tank per most of the makers.  That said I have a Lexus and a Saab both with injectors.  I have run them dry (one time) to find out just how much gas they hold.  Saab 16.4 Gal,  91 LS 400 22.3 Gal.  With no harm done, but I would not do this over and over.

As for when do I fill up.  When on a road trip I start looking when I'm down to about 5 gal left.  This gives me about 100 miles to find a gas station (unless I know I will be driving though a long streatch of road with no gas or only Expensive gas).  When at home I never go below 1/2 a tank.  It's that safty thing.  If there is an emergancy I can hit the road and not have to find a gas station.

But this is me.  If you want to run your car down to 1 gal eveytime nothinmg says you can't.

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i'm trying to do what's best for the car...

[RX in NC]

To minimize emergency issues as well as fuel pump issues, make it a rule of thumb to never let your vehicle get below a quarter-tank. I prefer to fill up when I get to a half-tank or slightly below, regardless of which vehicle I'm driving.

[LexKid630]

To minimize emergency issues as well as fuel pump issues, make it a rule of thumb to never let your vehicle get below a quarter-tank.  I prefer to fill up when I get to a half-tank or slightly below, regardless of which vehicle I'm driving.

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i drive by at least 10 gas stations on my way to and from work everyday LOL (a 1.5 hour trip each way) so it's not like i have a problem. I'm more interested in the care of the car.