Fill Up when Tank is Empty, Quarter Full or Half Full?

None of the above. Our fuel varies considerably in price (in the last 4 weeks it has varied between $1.10 (today) and $1.34/litre). I fill up when it's cheapest. if I'm below 2/3 full.

I never let it get to empty - when the indicator says 100km to go, that's about the least I allow it to get. My daughter ran out of fuel once, and it cost me $324 (2002 dollars) to fix.

 

In my experience, the leading cause of fuel pump failure is a poorly designed fuel pump. The only fuel pumps I've ever replaced were on an Escort and a Cavalier, and can say for sure the Cavalier was never run extremely low of gas. My wife regularly ran her Mazda past the point where the fuel light came on and the fuel pump never failed. She also accelerates hard before the engine is up to normal operating temperature and has never worn out an engine. Point is most people don't worry about these things and don't have problems.

Running the gas so low that the fuel pump is starting to suck in air bubbles is certainly not good for the pump, but at that point the engine will start to stumble and your bigger worry will be making it to the gas station before you run out completely. If you do this regularly, you will probably be coasting to the side of the road quite often. That is, unless you have an old pickup truck with dual gas tanks, where you can switch to the other tank. Note that owners who did that regularly did have problems with fuel pumps.

I try to fill up around 1/4 tank. Not 1/4 tank on the fuel gauge which is usually pretty conservative, but 1/4 of actual fuel remaining. On my Prius this would be just before it goes down to the last bar on the fuel gauge, or about a 9 gallon fill-up on an almost 12 gallon tank.

 

I fill up whenever it's below 1/2 full on the gauge (I voted 1/2 tank) and passing by a Chevron. A few reasons:

1. Our consumption is very low. Even filling up that soon, it's every 3 or 4 weeks.
2. I want to be the one filling up; it ensure my tank-by-tank mpg tracking stays "on track".
3. It's ultimately the most convenient, at least for me: don't want to be sweating, make extra out-of-the-way runs just to fill up.

 

I fill up when below the last gallon unless I'm at Costco buying something else and have the time.

But things have changed. It is possible I may have found a replacement.

Bob Wilson

 

I like to fill up at 1/4. With a 100+ round trip commute, that's every 3 days. But I'm not religious about and have no issues with driving until the last PiP blinks and DTE says 0.

You don't have to give up on maximizing a full tank distance. If you notice you are getting great fuel economy on the current tank, then go for it. If it has been a particularly bad tank then fill up at a 1/4 as usual. That's what I do. The recommendation to prolong fuel pump life is to not run low on fuel all the time. Every once in awhile is fine.

 

I always wait until the warning beeeeeeeep and then leisurely (within the next 50 miles) get gas at a clean station with nice, healthy snacks.

I can't speak for the G4, but the G3 has close to 100 miles of fuel left after the low fuel alert.
YMMV

 

I hesitate to post here because it will bring out the naysayers.
I have filled my tank 15 times since I bought the car, the average fillup is 10.5 gallons. I have not yet filled my tank before the DTE has reached "0". Average miles per tank is 688.

 

Naysayers?
I don't get it.
Why would somebody flop and twitch over how YOU fill up YOUR car??

My G3 is a work car with 103,000 miles....with probably 102,500 driven by me personally.
The only time gas has ever been added to my car before DTE=0 was when it left the dealership and when our contracted wrench swingers top off the car after maintenance.

Sounds like you're doing what I've been doing for about 5 years now....

 

Occasional exceptions.
But most often.
Gen 3 Prius.
I wait until the last pip...blinks..with warning...and DTE, cruising range to 0.
Then I find a gas station and fill up. Never feel rushed, or that it's an emergency. Always has had a gallon or more left.

Caveat as usual, your vehicle may differ.
Plus, I live in a pretty urban and developed area, which means once I reach 0 with my distance to empty, I'm going to be able to find a gas station pretty easily and quickly.

If I'm traveling "where the hills have eyes" or take the short-cut that the old man at the small grocery story warned me not to take? That is, in an area where gas stations may be far and few between, I obviously do not apply this protocol.

 

The fuel pump story is closer to an urban myth than fact. Before modern fuel injection, most fuel pumps were external and many were installed in the engine bay. Talk about heat. Internal fuel pumps are cooled by the fuel running through them. By design motorcycle versions are routinely above the fuel line. Finally, once the fuel rail is pressurized, the fuel pump only needs to run intermittently.

 

I only have gas stations every 54 miles so if I have less than 50 DTE I get gas. But I drive a very predictable route over level ground.

I expect that the Gen 4 has a very accurate, very conservative gas gauge, as Toyota burned the Gen 2 owners and still has not heard the end of it. (if you were buying a used Gen 2, I would be an adamant 1/4 tank guy)

'Social' reasons to fill up, it is much worse to be a stranded female than a stranded male. Do you travel in neighborhoods you would not want to be stranded in? Do you have passengers that you would hate to hear tell about the time you stranded them? Over and over? Do others drive your car you do not trust to check the gauge? (Or have money to buy gas?)

 

All of the above, and more, depending on circumstances.

Just before entering Canada or California, I'll fill up even when the gauge is at 80%, because the prices ahead are a lot higher. (Except on the east side of Glacier National Park, where prices this past winter were even higher than in neighboring Alberta.) Leaving those areas, I'll go 50 miles beyond DTE=0 unless weather is foul.

For trips elsewhere, it depends on a variety of circumstances: what gas price patterns I find on GasBuddy; what foul weather (low mpg) conditions are expected; how much safety margin I feel comfortable with under these conditions (1 to 4 reserve gallons), what external drag is added (bike or ski rack); and how far away the next expected service is:

gas163mi2.jpg by fuzzy1 posted Mar 13, 2014 at 9:27 PM

Now that I am retired from commuting, the car doesn't get enough miles between trips to need a fillup rule for home.

 

For me personally, I just think it's wise and good common sense to never let my fuel go below 1/4 tank. You never know what kind of crazy sh*t is going to happen in Southern California... and I don't want to be caught sitting in a car that's running on fumes.

 

Would cause a problem to those waiting for DTE to reach zero?

 

15 years ago, you could drive NV140/OR140 from US 95 to Adel Oregon, without passing any houses, let alone gas stations, about 140 miles.

At one point you can see Denio NV in the distance but you don't get there. (pop 47)

I have not driven since 2001, it may have changed.

 

Fill up where there is cheap gas and I need to do the deed, but never empty. Don't ever go there.

 

MPG matters, not MPT...

 

I live in the rolling foothills of the Sierra near Yosemite. It's a 25 mile round trip to get gas. During the summer months we have fire season. I've been evacuated from my home a couple of times. It's just wise to be prepared. I try to never let my tank get below half in any car and I fill up nearly every time I pass a gas station. That isn't that often.

 

i guess the answer to o/p's question is, do whatever works best for you. i do think the manual recommends fueling at least by when the last pip blinks and you hear the chime, dte = 0. the emergency reserve is there just for that, emergencies.
it's important to know the area you're in, if you don't fuel up sooner, although, entune may make unknown area's easier with gas finder.