dislexicon

Interesting. I hadn't even considered that as a possibility, so maybe there really is only 2.6 gal left when the DTE light comes on and the issue is with the "top" of the tank instead of the bottom. How are you avoiding overfilling the tank with this approach?

jahnjva

Do not push more gas in the tank when the pump stops.

Car Damage

These systems are only designed to work with vapors, not liquids. If you overfill your tank, it can cover the vapor intake hole with liquid gas, which can then be sucked into the charcoal canister. This can damage the canister and possibly other parts of the system, which will cause the car’s check-engine light to come on and could potentially cost hundreds of dollars to repair.

Safety Implications

Adding to the concern of overfilling is that gasoline expands in volume by about 1% for every 15 degrees Fahrenheit, according to Consumer Reports. As it’s not uncommon for a day’s temperature range to vary by 30 degrees, that means that 15 gallons of gas put into a tank when it’s cool will expand by more than a quart when it warms up by 30 degrees. If the tank is overfilled, that could be enough to push gas into the charcoal canister’s feed line or force a leak, which is a major safety issue.

RX500hBS

I am currently at 345 driven at this point on the odometer, and been running on empty for the last 50 miles (no bars on the fuel gauge).

my question to everyone;

1: when your RX500h says you have 20 miles to empty how many miles have you driven?
ME-280miles

2: what does the computer tell you your average MPG is?
ME-22.2 MPG

thanks

RX500hBS

WELL FINALLY RAN OUT OF GAS!
Here is what happened.

Started the car and within and noticed A/C was not blowing cold air, it was at that time I noticed the message in the dashboard.
"Engine stopped No Fuel"
Mileage was 351 miles driven since last full tank fill up (really concerned about that!).
The car was able to run in EV mode at that time, I thought about driving to the gas station, but decide to put in 1 gallon of gas.
Drove to the station and proceeded to fill up, at 12.586 gallons the car would not take any more gas. I mean would not take any more gas, I could even see it was full in the fill hole and not going down.
I turned off the the pump and closed the gas cap, started the car and the gas gauge did not go all the way to the top (last bar did not fill in).
Let the car run for about 2 or 3 minutes and decided to put more gas in.
Started to pump gas again and was able to put in another 3.679 gallons of gas at that point.
Started the car and the fuel gauge went all the way to the top.
So 12.589 + 3.679 + 1 = 17.268 gallons
What I am really upset about is that would mean that I am getting 20.40 MPG on a 17.2 gallons of gas, which it HORRIBLE for this RX500h Lexus!
AND HERE IS THE STRANGE PART, if you listen to the video (short because of limited file size) you can hear a noise almost like a whistling noise, that happen the whole time I did my first fill up.
Almost like it was pushing air out of the fuel tank, causing the whistling sound.

If someone has got lexus to fix this please let me know, otherwise my next stop is Lexus Customer care about this issue..

Urlik

Hmmm, I'd love to see schematic on this tanks design. Might find there is a transfer pump in there.

lexusnyca

Sounds like a vapor lock condition of some kind.

As noted above, on any modern car, never overfill the gas tank. First click, stop immediately, no rounding up. In fact, knowing how much gas it should take and short filling it even before the first click, is better.

Not sure if this tank has baffles in it, typically sports cars have this to prevent fuel starvation during high speed cornering that might push the fuel away from the pump pickup.

Urlik

I might have to try filling the tank next time it’s at an eighth then running the car for 2 to 3 minutes and see if it takes 3 more gallons. Really curious on what is happening in that tank now. Could be baffles. Could be a transfer pump to another part of the tank.

Good job RX500hBs!

Vanguard

This isnt overfilling, its 3-4 gallons extra. There is something wrong with the fuel tank.

ggebhardt

If I run the gas pump at the station at full speed, my gas hose nozzle will actuate the "stop" way before the vehicle is full.

I have to pump the gas in at about half speed to avoid this.

daryll40

Same here, but it was also that way on my old 2020RX and my 2021 Subaru Crosstrek. And many cars that I’ve rented.

Tacoshawn

First fill of the RX350h this morning. Low fuel light on, filled with 12.1 gallons, just like our RX500h was.

ggebhardt

‘Are you sure it was full of did the auto stop function kick in on the fuel hose? Mine does it all the time. Does it show full on the gauge?

RX500hBS

I think we all agree that the pump will kick off several times while filling up if you try to pump the gas as full speed from the pump.
The question we all have is, is 12 to 13 gallons full because there is still 4 to 5 gallons in the tank.
I was told by my lexus service department when I first reported the issue that the tank does have a baffle in it (don't know how it works).
If you go up in this feed and I listen to the video attached to my 07-05-23, 01:13 PM RX500hBS post you can hear the air being forced out of the tank after I ran it to empty.

Tacoshawn

Yes, gauge reading is full.

There is some type of flaw in the tank/sensing design versus the Lexus capacity specification. Not world ending will just deal with it. I posted here originally to share as it was an odd finding. Looks like a systemic occurrence across at least a portion of the 5G RXs.

RX500hBS

My only issue with this is we take two 750+ road trips a year and not having accurate gas gauge make me have to stop for gas more often.