Distance to drive after low fuel light comes on

skag1T

New member
2018 SR5

I've never seen the low fuel light come on, to the point where I thought the 4runners don't have it. I know it is mandated by law, etc.

So I drove the other day until the lght actually came on. I was at about 360 miles on that particular fill.

The light came on just when the indicator tip touches the top edge of the E line.

I drove within the "ECO" range - i tried to avoid the ECO indicator to move all the way to the right. Max 60 mph or so, not on highway but on side streets.

I drove 50 miles on it, and was still going but it was getting late and I called it. When I stopped, the needle was almost past the lower edge of the E mark.

I added 2.5 gallons from a small jerry can, and the needle didn't seem to move at all, and the low light was still on.

Then I added 5 gallons more, and the needle went up to the first 1/4 indicator.

At the pump I topped off the fuel tank and my 5gal + 2.5 gal Jerry cans - all in all it took about 22.5 gallons -
I know that the manual says the tank capacity is 24 gallons, my measurements are probably a bit off.

At least now I know that I can drive ~ 50 miles on low fuel indicator.

I might repeat this until I actually completely run out of gas and the engine dies, but I think at 50 miles I was close to that point.
 
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ive ventured 30 miles into the light with the needle hitting the E. Was i shittin my pants? Yes I was knowing that the 4runner is only capable of 12mpg:gun5:
 
Thanks skag for that public service. If you ever do run it dry on purpose, please take note of how it runs dry. I’ve had cars that could hobble along on fumes for a mile or so, and others that would die abruptly and stay dead until refueled.
 
My lowest was down to 6 miles to E. From what I remember I put about 21.5-22 gallons back in when I was able to fill up. I think the counter is a little conservative on purpose.
 
Running dry with a submerged fuel pump is not advised. Fuel is the pump’s lubricant and cooling system. Good way to burn out your fuel pump and incur the expense of dropping the tank to replace.
 
When my truck says 0 miles to E, I still have about 3 gallons left. My fuel gaude really only seems to reflect about 20 gallons of the 23 gallon tank. So much so, in fact, that I thought the truck had a 20 gallon tank for the first 2 years, until I randomly came across my window sticker and saw that it was 23.
 
There are too many factors at play to put a hard and fast number on it. Altitude, temperature, terrain, area (city/highway), vehicle load, tire size, tire pressure, number of accessories being run and about a million other factors will affect when the go juice is gone.

As discussed, running a low fuel tank with an in-tank pump is asking for trouble. Not just running it empty but running it low can damage the pump when fuel is sloshing around in the tank away from the pump during inclines/declines or when turning. It also agitates the sludge and debris that accumulates at the bottom of the tank so it gets sucked up by the pump causing premature fuel filter wear/clogging, straining the pump and causing failures. It's why manufacturers build in safeties to keep us from running out of gas. These include setting the gauge and light to read E when there may be as much as 3 gallons left in the tank and the Lie-O-Meter giving a DTE that is conservative. It's all to protect us from ourselves.

I rarely let any vehicle I own get below 1/4 tank but I don't relish dropping tanks and replacing fuel pumps/filters etc.
 
The 2018 user manual says the low fuel warning light comes on when approximately 3.5 gallons are left in the tank (23 gallons capacity). How much of that 3.5 gallons is usable is uncertain
 
Its one of the great mysteries of the universe...kinda like..

How many licks does it take ro get to the center of a tootsie roll pop?
 
Speaking in very general terms, when the pump is no longer effectively able to suck fuel from the tank, you have about 1/2" to maybe an inch of fuel left in the fuel tank on a level surface. The fuel pump housing (the big plastic bucket that everything sits in) itself will be filled with fuel as that's what it uses as a reservoir to keep the pump cool and it doesn't really drain out fully even when the tank is basically empty.

At least that's been my experience when doing fuel pump recalls with customers who brought their vehicles on basically fumes, as well as fuel tank campaigns on the RAV4's, and the occasional fuel tank we have to drain and such for people who ran diesel or bad fuel in their tanks.

I will also point out that a lot of our newer combination meters & fuel sending units get a bit out whack if you are one of those people who top off a lot or don't fill your tank in large amounts. You can also have your lift affect the level sensor and skew the way the vehicle interprets the fuel sender reading.

But, usually 20-30 miles give or take when you're sitting at "E" is probably a good estimate.
 
My '21 Manual also states ~3.5gal when the low fuel light turns on. pg 477.

I get anbout 18 mpg, so 3.5 gallons would give me about 60 miles.

So I guess I had about 1 gallon left when I added the 2.5 gal jerry can - the needle didn't seem to move from E and the light was still on.
 
Bottomline is that the "idiot light" is there for several reasons and is not an Exact science. It comes on based on your cumulative mpg for your style of driving. People complain about it coming and it isn't "empty". Imagine riding on a trail that and tha trail is 30 miles from your main road and another 20 from a gas station. Would you rather know you have a safety margin for a safe return or simply run out within a mile or two if it coming on?

As for the fuel gauge... it is not an exact indicator but rather for general purpose info. In my previous JKU I was climbing some long ass hills on I-70 in Colorado and my needle buried itself, when I came out the other side, idiot light turned off. It was solely based on low fuel, but pump location within the fuel cell.
 
Speaking in very general terms, when the pump is no longer effectively able to suck fuel from the tank, you have about 1/2" to maybe an inch of fuel left in the fuel tank on a level surface. The fuel pump housing (the big plastic bucket that everything sits in) itself will be filled with fuel as that's what it uses as a reservoir to keep the pump cool and it doesn't really drain out fully even when the tank is basically empty.

At least that's been my experience when doing fuel pump recalls with customers who brought their vehicles on basically fumes, as well as fuel tank campaigns on the RAV4's, and the occasional fuel tank we have to drain and such for people who ran diesel or bad fuel in their tanks.

I will also point out that a lot of our newer combination meters & fuel sending units get a bit out whack if you are one of those people who top off a lot or don't fill your tank in large amounts. You can also have your lift affect the level sensor and skew the way the vehicle interprets the fuel sender reading.

But, usually 20-30 miles give or take when you're sitting at "E" is probably a good estimate.

Thanks for that explanation. Most drivers have little knowledge of the fuel system and sometimes refer to old automotive hearsay. Can you clear up some of these?
1. Will any damage occur if the engine runs out of gas while driving at highway speed?
2. Will the fuel pump overheat and be destroyed?
3. Will water from the bottom of the tank get sucked up into the engine and damage it?
4. Will sludge/rust from the bottom of the tank get drawn up and clog the fuel filter?

Thanks.
 
Last week, I had driven my 4Runner to 1 mile to empty. I was already headed to the gas station so I wasn’t concerned. The low fuel light came on around 20 miles to empty. Topped it off at around 20.5 gallons. $106 dollars lol


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