Almost ran out of gas!

[AlexN09]

So I know that our tanks hold about 20USgal, according to the manual, but every time my DTE reads - - - (or zero) I fill up and only put in 17 gallons. So I was thinking theoretically I should have another three gallons and be able to drive another 90 miles!!

So I took a 75mile drive across the state today and decided I would just fill up when I got to my destination. Well gas was 20c more per gallon there so I decided I would push it and drive home (even though my DTE read zero miles).

When I got home and filled up in my neighborhood I couldn't wait to see how much gas I needed!

Here's the results!



And here is my trip meter for the tank



Just thought that was cool and ballsy and wanted to show everybody my achievement!!

[mattyfo0z]

hahah that's crazy. not very good to do that too often though... i always put $40 in or so when i the little warning message pops up (25 miles or less). wish i could only pay $66 to fill up though

[asoomal]

That's bad for the fuel pump...really bad.

[rcboy514]

I ran out of fuel once....it was near my college at lunchtime on a 4-way stop lol

I had gone to fill up before class and the station had all the pumps closed so I was like eff it i'll get gas after class.....didn't make it. Lucky a few passers by jumped in and helped me push it off the road and I had to have my mom bring me a gallon of gas lol

[AlexN09]

hahah that's crazy. not very good to do that too often though... i always put $40 in or so when i the little warning message pops up (25 miles or less). wish i could only pay $66 to fill up though

Are you using premium or something??

[AlexN09]

That's bad for the fuel pump...really bad.

And why is it bad? I would imagine they wouldn't place the fuel pump somewhere where it would be running dry or something..

[Innovazn]

That's bad for the fuel pump...really bad.

And why is it bad? I would imagine they wouldn't place the fuel pump somewhere where it would be running dry or something..

From my understanding (quote if wrong please) but when you suck your tank dry, youre sucking up the "crud rust etc etc" from the bottom of the tank and clogging the filter.... Now for MEE... common sense dictates that the pump would be sucking from the bottom of the tank REGARDLESS cuz you know... gravity and all, and common practice is change fuel filter every 3 oil changes... wouldnt make sense if it was up top or off to the side sucking gas.

[mattyfo0z]

hahah that's crazy. not very good to do that too often though... i always put $40 in or so when i the little warning message pops up (25 miles or less). wish i could only pay $66 to fill up though

Are you using premium or something??

yep, owners manual reads 91 premium as the required octane for the 2008 3.5se. last time i filled up for 4.59/gallon

[AlexN09]

From my understanding (quote if wrong please) but when you suck your tank dry, youre sucking up the "crud rust etc etc" from the bottom of the tank and clogging the filter.... Now for MEE... common sense dictates that the pump would be sucking from the bottom of the tank REGARDLESS cuz you know... gravity and all, and common practice is change fuel filter every 3 oil changes... wouldnt make sense if it was up top or off to the side sucking gas.

My thoughts exactly! Well I don't know much other than my car ran great the whole time and It's very new so I doubt the fuel tank is full of junk anyhow.

And Matt I thought it said 91 was recommended but not required?

[Innovazn]

yep, owners manual reads 91 premium as the required octane for the 2008 3.5se. last time i filled up for 4.59/gallon

says regular 87 for the 2012 V6 XD

[mattyfo0z]

i know lol my cousin has a 2010 3.5se, and his has the same 87 octane requirement. i'm thinking nissan bumped down the compression a bit on the vq's in order to lower the octane. i dont mind, the higher the compression the better for me, since i'm never planning on going the f/i route.

[asoomal]

That's bad for the fuel pump...really bad.

And why is it bad? I would imagine they wouldn't place the fuel pump somewhere where it would be running dry or something..

Fuel pumps use the gasoline around it too keep them cool. If you were to look in a tank, you'll see a bunch of baffles surrounding it, to keep the fuel from sloshing it away. If you repeatedly drive on empty, you WILL burn out your fuel pump.

[AlexM.]

Haha damn that IS balsy..

and common practice is change fuel filter every 3 oil changes... wouldnt make sense if it was up top or off to the side sucking gas.

Is it easy to replace the fuel filter? I've never had mine replaced...

[Innovazn]

Haha damn that IS balsy..

and common practice is change fuel filter every 3 oil changes... wouldnt make sense if it was up top or off to the side sucking gas.

Is it easy to replace the fuel filter? I've never had mine replaced...

should be 2 hoses and a screw... at least thats the case for my Pathfinder back in the day...

[rcboy514]

yep, owners manual reads 91 premium as the required octane for the 2008 3.5se. last time i filled up for 4.59/gallon

geez lol Here it's ~$3.60 for 91 octane.......my problem is that all 3 of my cars run on premium lol

[AlexN09]

Fuel pumps use the gasoline around it too keep them cool. If you were to look in a tank, you'll see a bunch of baffles surrounding it, to keep the fuel from sloshing it away. If you repeatedly drive on empty, you WILL burn out your fuel pump.

Ohhhh thank you!! This makes sense completely and I'm glad you let me know. There really was no reason why I waited so long to fill up, I just felt like seeing if I really could go that extra 90 miles!

I ALWAYS wish I would have gone for a V6 coupe. When I bought mine I was just thinking about fuel economy but now that you bring up the point of regular versus premium gas I'm really glad I'm driving the 2.5!! Although at times I swear this car is the SLOWEST thing I've ever driven. It's so so sad to me lol

[SHIFT_COUPE]

I haven't run out of gas in this car...yet...

I've done it once. It was about 2am and I was a mile or two away from home. Had to walk home and get some gas which thankfully I had. That was a fun night!

[skiski329]

i really don't recommend doing this. Especially in older cars. there is always some dirt or sand in your gas tank that comes from the fuel pump. overtime this stuff settles to the bottom of your gas take and if you let the tank run low than you run the risk of this stuff getting sucked up at the bottom of your gas tank and going through your engine.

[incREDibL3]

damn! i just fill my tank today and i fill up with 71.00$ and that's not on empty. jealous haha

[sndtgr08]

That's bad for the fuel pump...really bad.

And why is it bad? I would imagine they wouldn't place the fuel pump somewhere where it would be running dry or something..

Its every simple. Its a PUMP. It Pumps liquid. It is not a Vacuum. Very few heavy duty industrial/commercial pumps Can acctualy suck with power, without causing strain/damage to the pump. 95% of pumps made are designed to have pressure pushing in on the intake side and most are made with the intake hole bigger. If you do not have the minimum rated pressure on the intake side, you will damage the pump. Running the pump dry will damage the pump. Even if it is a magnetic drive style pump, the plastic impeller inside will start to over heat, warp and melt out of shape. Then your done for. Even on Pumps that let you ajust the pressure, it is ALWAYS ajusted on the output side, Never restrict the input side unless you want pump damage.

The power use of an electric motor changes depending on physical load. When your tank is full and your at idle it takes a tiny bit of power to push the gas up front, hell the weight of the rest of the liquid does most of the work. When you tank is empty it takes alot more electricity to pump the same amount of fuel. More electrictly means more heat. When you run your tank dry like that, you put 100x the strain on the pump. Now it has to do twice as much work by having to pull AND push the liquid. I am sure that the pumps are rated to run non-submerged, but it also means that at that time it is working twice as hard and generating a lot more heat and wear. Also I would think that Nissan expects you to run out of gas once in a blue moon and has tested for that. But I would still avoid it whenever possible

I am amazed you fit the full 20g in your tank, but there are reasons its telling you its empty and it still has 3 gallons left.
1) Emergency gas reserve
and more importantly
2) The fuel pump requires about that much to operate cooly and efficiently.

Hope that helps

[AlexN09]

Haha thank you sndtgr08!! I actually know a lot about pumps and especially magnetic drive pumps (like in those used in the aquarium trade) and I was just under the impression that based on the fact that the gas tank isn't very tall at any point, there was never actually much pressure relieving strain on the pump. I also assumed there was an extra half gallon or so that they weren't telling us about. Anyhow I appreciate your detailed explanation and I can't say I disagree with any of it! I'm guessing it really is bad for the pump.

I just wanted to do it for fun and generate some discussion about whether or not it was really bad!!

[Innovazn]

Haha thank you sndtgr08!! I actually know a lot about pumps and especially magnetic drive pumps (like in those used in the aquarium trade) and I was just under the impression that based on the fact that the gas tank isn't very tall at any point, there was never actually much pressure relieving strain on the pump. I also assumed there was an extra half gallon or so that they weren't telling us about. Anyhow I appreciate your detailed explanation and I can't say I disagree with any of it! I'm guessing it really is bad for the pump.

I just wanted to do it for fun and generate some discussion about whether or not it was really bad!!

i believe theres also something about lubrication using the fuel in the tank... not sure about that though

[funkee]

Your filter probably doesn't have that much gunk, seeing as how the car has less than 7,000 miles. But be careful. You might find yourself in a spot where you refill the tank, but you can't start the car, because the filter is clogged with sediment. Then you'll need to get the filter out and replace it if its damaged, or wash it, soak it in fuel and put it back.

[sndtgr08]

I actually know a lot about pumps and especially magnetic drive pumps (like in those used in the aquarium trade

Thread Jack. Fresh are Marine!? I am guessing marine because most fresh water noobs never bother to read up on the pumps like the the salt water fanatics. You have a tank currently up and running?

[AlexN09]

Haha no its cool, I have kept both and currently keep both. I've had a lot of success with reefs and now planted tanks! Do you keep fish?

[Towncivilian]

Most new vehicles today have no in-line serviceable fuel filter and instead use a sock or mesh filter on the fuel pump itself. The only reason you'd need to change it is if you were replacing the fuel pump. The Altima & its coupe variant do not have serviceable in-line fuel filters.

[sndtgr08]

Haha no its cool, I have kept both and currently keep both. I've had a lot of success with reefs and now planted tanks! Do you keep fish?

Started a thread :

what-s-in-your-aquarium-t558324.html