GX Fuel Tank Capacity

[Jay98]

I have a 1998 GX, and I have never put more than 6GGE in the tank (once when it ran out of gas). My usual fill is about 4GGE at 3600psi with the needle showing about 1/8 tank or less. Sometimes I get 5GGE at a station with pressure closer to 4000psi.

Is this normal? I am concerned that the tank may have a significant amount of oil in it, and I want to determine if I should drain it.

Thanks,
Jay

[venomous99]

Re: GX Fuel Tank Capacity

that seems normal based on what ive been seeing on my fillups. on 3600psi, i fillup anywhere from 4 to 5gallons w/ the needle about 1/8 to empty. if you're concerned about the incoming fuel quality as part of normal maintenance you'll want to inspect the fuel filter.

[Curtis]

Re: GX Fuel Tank Capacity

This is what I normally get in my 2004 as well. You would more than likely have a buildup of moisture in the tank, as opposed to oil, but your numbers are apparently normal for vehicles posting such data on this site. Remember, once the fuel cools down you'll be able to add approximately 1 gge more into the tank. Heat expansion prevents you from getting a true "fill" when fast filling. The "cool down & top off" trick is very handy when you're going to make a trip and you need that extra 30-40 mile range.

[thad_morrow]

Re: GX Fuel Tank Capacity

This is what I normally get in my 2004 as well. You would more than likely have a buildup of moisture in the tank, as opposed to oil, but your numbers are apparently normal for vehicles posting such data on this site. Remember, once the fuel cools down you'll be able to add approximately 1 gge more into the tank. Heat expansion prevents you from getting a true "fill" when fast filling. The "cool down & top off" trick is very handy when you're going to make a trip and you need that extra 30-40 mile range.

So, how do you do that? Do you fill up till it stops and then unhook and wait? How long do you wait?

[Curtis]

Re: GX Fuel Tank Capacity

Cool down time can vary depending on ambient air temperature. Personally I fill at night on my way home and do the top-off the next morning on the way out. Waiting 10-15 minutes is probably not going to allow sufficient time for the fuel to cool. Temperatures inside the tank can well exceed 100 degrees, I've heard someone quote 140 degrees, but can't verify that. Try experimenting with the cool down time and let us know what u figure out. Just remember that air temp is a factor.

[Green GX]

Re: GX Fuel Tank Capacity

I've filled my '07 GX on a day when it was 70-75 deg. F, then waited 15 minutes. 15 minutes evidently wasn't enough, because the tank would only take about .1 gge more when I tried to top off.

Last night I put 3.79 gge into my tank and it was only up to the 3000 psi mark on my gauge when the pump shut off. The pump showed 100%. The outside air temp was about 57 deg. F.

I drove home, parked the car in the driveway last night. The outside air temp was 41 deg. F this morning when I left the house. I stopped by the station this morning, (44 deg. F,) and put 2.04 more gge in the tank. My gauge was up to the full mark and hadn't moved after driving about 3 miles more to work.

I don't know exactly how long it takes for the gas to cool, but overnight seems long enough.

Once upon a time I e-mailed the ScanGauge people asking if they can pick up any data points for tank temperature. I thought that might be interesting to watch. They never responded to my e-mail.

Bill

[btate]

Re: GX Fuel Tank Capacity

I have an 01 Civic and get between 5-6 gals in it when I am REALLY empty.

[qrp]

Re: GX Fuel Tank Capacity

Is there a way to remove moisture from the tank?

[lcovelli]

Re: GX Fuel Tank Capacity

Is there a way to remove moisture from the tank?

When I fill up at the airport (SJC), I saw that they have an hose that is used to discharge tanks. The nozzle is a 3K blue nozzle and I am assuming you just plug in and it discharges the tank. By any means would the act of discharging purge residual water out of the tank?

[qrp]

Re: GX Fuel Tank Capacity

Perhaps I need to restudy boyle's law. If I fill my tank and the pump is 1500 psi, does that mean I am only getting half of the fuel from a pump at 3000 psi? When the gas enters the vehicle's tank (1998 gx) does the fuel system on the vehicle compress the gas to increase storage efficiency, or is my vehicle always subject to the pressure at the pump?

[Curtis]

Re: GX Fuel Tank Capacity

The dispenser is supposed to be temperature compensating, so it shouldn't really matter what the temp is. Private dispensers don't have to have to do this, but public refueling falls under Weights & Measures, so they check that you get the amount of fuel you're supposed to at a compensated pressure.

[raskell]

Re: GX Fuel Tank Capacity

According to my local CNG mechanic water must be physically drained from the tank. It lays in the bottom of the tank as gas condensate, a mixture of water and lighter molecular weight hydrocarbons similar in appearance and smell to lighter fluid. It is not usually necessary to have the tank drained using commercial filling or residential gas. The highest water content comes from 'free gas wells' with raw (unrefined) gas of which we have many such wells in rural Ohio. Venting off your entire tank will still leave the condensates behind.

[nttrainer]

Re: GX Fuel Tank Capacity

I just filled a 2009 GX today and got in 7.11 GGE. The pump read about 3800 psi when it shut off. Air temp around 75F. It had no bars showing and of course the low fuel light had been on for a while (maybe 20 miles). That's about the most I've put into a GX standard tank. I got 9.8 GGE into a Camry tank before. I'm not afraid to let them run low (the Camry light flashes for a couple of miles before you run out). The Honda was showing 240 miles on the trip odo but as I recall I was only working on a 3200psi fill.