Hello everyone. I used the search function, but couldn't find exactly what I was looking for. I just purchased a 2008 g35sedan. I know our fuel tanks are 20 gallons max. I've run my car from a full tank to "completely empty" with the odometer warning me that I had 0 miles left to travel, basically on a completely empty tank. So one would figure If my fuel tank can hold 20 galons and I am on "DEAD EMPTY" how is that I can ONLY fill up 17 gallons.

So once again my question is: How come when I run to empty I can only fill up 17 gallons?

Do I need to take this to the dealer and if so what do I tell them? Or am I just overthinking it and filling up 17 gallons on dead empty is normal?

 

That is normal, they leave a reserve in there for idiots that run it to empty when it says that on the dash.

 

i think he just called u an idiot...

the 3 missing gallons is your reserve. makes u think u have an awesome car.

 

The important thing is it is not good to run the tank low since it promotes condensation in the tank and can possibly allow sediment in the bottom to clog yor fuel pump. Also if you do run out it is not good for the fuel pump to run dry.

 

The most I've filled up was 17 gallons as well. I never let the gas drop to the reserve now. It just makes me feel much... better.

 

All cars with distance to empty guages do this. THey say theyre out of gas way early. I think its because if they didnt a bunch of douchebags would sue them because they ran out of gas and the guage said 1 mile left. Plus the factor of making sure people dont run out of gas as it can be bad.

 

Thanks gao I don't think he called me an idiot. Believe you did, but that is not the point.

I guess I wanted to run it to 1 gallon left and pump 19 so I wouldn't have to visit the damn gas station too often.

Thanks for the information, but if any other members have any more to add that would be great!.. Thanks again though.

 

Actually, running a tank too low can cause the pump to overheat, as it's submerged and uses the fuel as a coolant as well.
Running completely empty isn't the best idea.

Just use the gauge.
When it says it's close to empty... fill 'er up!

 

My gauge dropped from 12 miles to zero today while sitting at a stop light. No need to panic, went to a nearby gas station and filled 17.25 gallons without topping off. I also have noticed that when the gauge gets to around 40 miles remaining it seems to drop to nothing rather quickly if driving around town, no where near 40 miles driven. Yet to run out of gas but have had it show zero miles remaining a couple of times.

 

i love miserable wise-asses who make fun of people who run low on gas..

As if there is a gas station every mile, of every road, in every town, in every state... And second of all, like nobody has ever forgot to check, or was in a rush

Now who is the moron...

 

Seriously.... not trying to look like a wiseass...

I try to always keep the car above 3/8 - 1/2 tank full.
Yes, this causes me to visit the gas station more often, but if there was ever an emergency and I needed to jump into my G and get somewhere fast, the last thing I wanna do is drive to a garage for gas first.

It's tough to get used to at first but once it's habit, it's no big deal and it's probably only one extra visit per week to the station anyway.

 

^^^+1 I have also always done that, especially during the winter moths when I try to keep it well above the half.

 

I've always heard that, but common sense tells me otherwise. I'd like to see some sort of proof on this. I'm skeptical.

It's closed system, so how is water getting in to form condensation?

Also the pump is at the bottom of the tank and it draws fuel from the bottom of the tank... so what does it matter if there is 3 gallons or 20 gallons. Sediment sinks to the bottom of the tank, so it's always going to go through the pump.

Now I do think that extremely low fuel may burn out a fuel pump if it's sucking air. But I am also skeptical that Gas is a "coolant" for a fuel pump. How hot can a pump get thats pumping 1 gallon every 20 minutes... we're not talking about a commercial sump pump blowing out 20 gallons a second here.

 

[QUOTE=kring]

It's closed system, so how is water getting in to form condensation?

It's not a closed system, otherwise as you use gas a vaccuum would form in the tank. Cars used to come this way, but some gas tanks were collapsing with age, so they started venting the gas caps.

Air gets in, condenses against the inside tank walls.

 

I may be posting outdated or inaccurate data (or "old wives tale" info), but doesn't part of the benefit of not driving down too far into the gas tank (avoiding going close too empty) is that you avoid sucking up crap (I know, technical term), that may accumulate at the bottom of the gas tank? Along the same lines of avoiding filling up while the tanker truck is re-filling the stations's gas supplies.

I am not a mechanic, nor do I play one on TV. So correct me if I am wrong...