Fuel Lesson Learned

[Mavster Mechanic]

I guess a simple way to put it is:

The space between E and F = 13.8 in a hybrid.

The space between E and F = 16.5 in an EB.

There can be gas above "F".
There IS gas below "E".

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[Mavster Mechanic]

I put 15.8 gallons in my hybrid one on a very slow pump. My MPG's gage read 43 which calculates to take 13 gallons as well as the gass gage itself. There was no spill ove which meens that the pump had an anti spill over syphon. I have noticed that there are a lot of slow pump that don't trigger off with anti spill over syphons. Be careful. Calculate before you fill.

To be clear, calculation of what you "should" pump in is meaningless.
It can vary a lot for a lot of reasons.
The pumps are not likely to cheat you.
Design allows vapors to flow in reverse, not liquid.

When I am on a slow pump, extra fuel does go into my tank. That NEXT tank usually takes me something like 800 miles instead of 700 miles.

The fuel dispensed was accurate.

 

[WBS]

And so instead of refueling with .4 gallon left, I actually had 3.4 gallons (at least) left. I had no idea. This forum provides useful info for new Mav owners.

 

[HeyBales]

I hit 0 DTE last night - knowing I had easily 60 to 80 miles to go - so didn't have to hit the 1st gas station on final errands.
Instead went an extra 4-5 miles to station near store I was going to - noting along the way all the increases to 2.89 that happened when I know I'd seen 2.78 earlier in week.
Got to Casey's I was curious about - 2.73.
Ya, I'll take that on empty tank. 14.5 gal on 2nd click.
(which is no where near overfill - I can hear the sounds in pipe, still a ways to go, no fume recapture surround, so can hear it well!)

It's been well over a year since there has been any gas price movement beyond summer/winter blend changes - so the desire to wait a few days as you see it lowering really hasn't been a thing.
But lately it's been happening again - so it's good to know I may need to go into better watchful mode.
I know - this fillup only a difference of $2.32 saved - it's the principle of the thing!

 

[Mavster Mechanic]

@HeyBales

Does Casey's still have breakfast pizza?

I used to live "mid country" and really liked their breakfast pizza like 20 years ago.

 

[HeyBales]

@HeyBales

Does Casey's still have breakfast pizza?

I used to live "mid country" and really liked their breakfast pizza like 20 years ago.

Driver yesterday got it about 11 am - forgot to ask how he liked it, since I know his tastes a tad more refined than mine.
I like their new coffee method - 3 units with about 3 different coffee types on each in whole bean - grind and brew per cup.

 

[Brent@ANParts]

I had an old Mazda that would cut out on a hill with a quarter tank. Since then I always try and keep my fuel above that, even though we have come a long way since the early 90's.

 

[Cancunbadlands]

I filled my tank this morning.
42 MTE. Pump clicked off at 13.1 gal. An extra squeeze took it 13.8.

I'm getting an average of 35 mpg and about 450 miles between fill ups.
Way better than my previous 1500 Silverado.

Don't you never do an extra squeeze never!

 

[Ranko Kohime]

I have heard a faint buzzing sound once near the back left passenger seat area while driving during low fuel level. I wonder if it was the sound of the fuel pump?

Probably. Without a mass of liquid to muffle the sound it is usually more audible.

Unlike the turn of the century Chevy’s, which you could hear with a full tank, inside the cab with the windows rolled up and the engine running.

 

[Ranko Kohime]

Don't you never do an extra squeeze never!

I put on my villain cape, and I do 3 extra squeezes while twirling my mustache

 

[MakinDoForNow]

To be clear, calculation of what you "should" pump in is meaningless.
It can vary a lot for a lot of reasons.
The pumps are not likely to cheat you.
Design allows vapors to flow in reverse, not liquid.

When I am on a slow pump, extra fuel does go into my tank. That NEXT tank usually takes me something like 800 miles instead of 700 miles.

The fuel dispensed was accurate.

One of my HS buds worked for txdot measuring pump out put. When one was "OFF" he would lock it until it was recalibrated. He retired 16 years ago. Maybe today's pumps are true and stay true. He did have certain stations which had pumps which would pump less than metered amount from time to time more often than others....

 

[Bret Grabber]

2025 XLT AWD Hybrid. Pulled into refuel with 40 miles on DTE indicator. Low fuel warning came on at exactly 50. Truck took 13.4 gallons (13.8 capacity). Much too fine for me. I will refuel in the future before the 50 mile low fuel warning in the future.

Ouch! Word of advice. Your fuel pump needs gas in the tank as coolant. It pushes gas up to the hot engine compartment, the engine uses what it needs and the rest, after picking up not only heat from the pump pressure but now the engine compartment, heads back to the tank. With low volume in the tank now, the pump's "coolant" is not doing what the pump needs it to do!
You should never run the tank, at least on purpose, below a quarter full. I sold lots of fuel pumps to folks who ran their tanks consistently low or filled when the warning light came on. What ate em up? Overheating! Save yourself a costly repair and fill er up sooner!

 

[HeyBales]

Ouch! Word of advice. Your fuel pump needs gas in the tank as coolant. It pushes gas up to the hot engine compartment, the engine uses what it needs and the rest, after picking up not only heat from the pump pressure but now the engine compartment, heads back to the tank. With low volume in the tank now, the pump's "coolant" is not doing what the pump needs it to do!
You should never run the tank, at least on purpose, below a quarter full. I sold lots of fuel pumps to folks who ran their tanks consistently low or filled when the warning light came on. What ate em up? Overheating! Save yourself a costly repair and fill er up sooner!

And then again in my prior 6 vehicles over 35 years, I was almost always running down to the fuel light coming on, if it had one (usually meant 2 gal left), or below the E line - unless I saw prices going up and just had to get in early.
And except for 1 - all used vehicles with 80K or higher starting mileage when I got them.
VW, Nissan, Mazda, Fords, Toyota.
Never had a fuel pump issue. Carb to FI of some sort.
Always in city with good fuel options though, didn't do the scary stations. Tried never to fuel-up when their tanks were being filled.
3 of those older vehicles, and current Mav - seen in the repair manual where the pickup line was in the tank, and where pump sat - to never have a concern over cooling due to placement.

I'm now going to add the PID for temp on pump just to see in scan data.

 

[mepot101]

I'm all in on the 'don't run the level too low' group.
My wife used to run the level low in our 2003 explorer sport trac. The pump would get hot and not re-start in the summer here in Fl.
I replaced the pump, and it never happened again as long as we kept the level at least 1/4 tank.

 

[Carlitos_92]

Never had a fuel pump issue. Carb to FI of some sort.

Haven't had a fuel pump issue since my 1976 Buick 40 years ago, and that was because it was a piece of shit, not because I ran it low on fuel. I have since run Japanese cars into the negative DTE numbers.

I know there is the adage about fuel used for cooling the pump, and I have probably even shared it myself out of an abundance of caution. In practice, I have found that it is way overblown.

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