Why Topping Off won't kill your truck

[The Real Maverick]

Why "topping off" is OK as long as you don't spill and pollute.

(And why your car care nut and Uncle Joey have unfounded worries about the "carbon filter canister".)

I put "topping off" in quotes because it's really not possible to, even if you wanted to. So everyone can relax a bit if they want.

This thread is not meant to be a debate and I'm not telling anyone what they should or should not do.

This is information. Information that shows the risks of the past likely no longer exist today.

That said, in the hybrid with capless filler tube, I find it fills fully, reliably, repeatedly with just three clicks. No need to go beyond that.

Here is the fuel system diagram from Ford.

1: fuel fill tube
2: fuel module
3: fuel level sensor
4: fuel tank
5: fuel vapor return line
(5 is what people worry about needlessly)
6: fuel pressure sensor
7: refueling vent valve that opens when you push the refuel open door button
8: fuel tank pressure control during operation
9: carbon canister
10: vent valve
11: vent to atmosphere
12: vent to engine
13: recirculation valve
14: engine intake manifold

The particular technique different individuals use to refuel their trucks should have no effect on the much worried about "carbon canister".

Hope that helps some of you sleep peacefully. How that canister got ruined in a 1998 vehicle bears no resemblance to the hybrid Maverick of today

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[The Real Maverick]

Additionally:

"The EVAP canister is used on the sealed EVAP system to collect fuel vapors during refueling only. A valve inside the fuel tank mounted fuel vapor tube assembly prevents liquid fuel from entering the EVAP canister and the EVAP purge valve under any vehicle altitude, handling, or rollover condition."

 

[zacatac]

I find that I don't particularly miss the maybe 10-20 miles of range I lose from only going until the pump shuts off the first time. When it clicks once I'm done.

 

[Tom 71 Maverick 24]

Once in a while, you come across a pump that likes to shut off prematurely. Or a vehicle like my 2003 Dodge truck that had a habit of shutting off very early if you tried to pump too fast. A PiTA in that respect, but that isn't the case with our mavericks. Still, when calculating MPG, consistency in filling practices is essential.

I go till it clicks, wait 30 seconds, and pump more until it clicks off again. After that, the additional gas put in the tank is very minimal so I'm fine just stopping there.

 

[Deleted member 5352]

Once in a while, you come across a pump that likes to shut off prematurely. Or a vehicle like my 2003 Dodge truck that had a habit of shutting off very early if you tried to pump too fast. A PiTA in that respect, but that isn't the case with our mavericks. Still, when calculating MPG, consistency in filling practices is essential.

I go till it clicks, wait 30 seconds, and pump more until it clicks off again. After that, the additional gas put in the tank is very minimal so I'm fine just stopping there.

I do the same thing. Fill till it clicks, wait 30 seconds, and do a top-off. Sometimes I can get the range over 400 miles doing that. The highest was 415. On average it's 385.

 

[oysterville]

Here's the opinion of the noted car experts over at Car Talk.

Personally when presented with two opposing opinions like this I consider the ramifications of being wrong. In this case if I decide to top off and I'm wrong, it could cause costly repairs or at least just be throwing money away as it goes back into the hose. If I decide to not top off and I'm wrong, then maybe I get fifteen fewer miles on this tank of gas.

I know which choice I'm making.

 

[Automan21]

I used to top off before in a different car that was new with only 10,000 miles that I put on it. After a handful of fill ups by topping off to the brim maybe a total of like 10-12 I got CEL pop up for emissions. Got a clogged / blocked EVAP canister since the fuel made its way back into it. Had to replace it and all was good in the world. The old canister was solid inside like it was fused together no air or liquids would be able to pass through even though pressure.

 

[MatthewPK]

I only top off for fun to see if i can hit the even dollar amount. If I go over I either accept failure or double down for the next dollar (gas price commensurate with risk!)

 

[Steve Urquell]

Owners manual for hybrid:

EcoBeast:

https://www.fordservicecontent.com/...A&div=f&vFilteringEnabled=False&buildtype=web

 

[OleFordGuy]

REFUELING YOUR VEHICLE -
HYBRID ELECTRIC VEHICLE (HEV)
WARNING: When refueling always
shut the engine off and never allow
sparks or open flames near the fuel tank
filler valve. Never smoke or use a cell
phone while refueling. Fuel vapor is
extremely hazardous under certain
conditions. Avoid inhaling excess fumes.
WARNING: The fuel system may
be under pressure. If you hear a hissing
sound near the fuel filler inlet, do not
refuel until the sound stops. Otherwise,
fuel may spray out, which could cause
serious personal injury.
WARNING: Do not pry open the
fuel tank filler valve. This could damage
the fuel system. Failure to follow this
instruction could result in fire, personal
injury or death.
WARNING: Do not remove the fuel
pump nozzle from its fully inserted
position when refueling.
WARNING: Stop refueling when
the fuel pump nozzle automatically
shuts off for the first time. Failure to
follow this will fill the expansion space
in the fuel tank and could lead to fuel
overflowing.
WARNING: Do not overfill the fuel
tank. The pressure in an overfilled tank
may cause leakage and lead to fuel spray
and fire.
WARNING: Wait at least five
seconds before removing the fuel pump
nozzle to allow any residual fuel to drain
into the fuel tank.

 

[The Real Maverick]

Here's the opinion of the noted car experts over at Car Talk.

Personally when presented with two opposing opinions like this I consider the ramifications of being wrong. In this case if I decide to top off and I'm wrong, it could cause costly repairs or at least just be throwing money away as it goes back into the hose. If I decide to not top off and I'm wrong, then maybe I get fifteen fewer miles on this tank of gas.

I know which choice I'm making.

The point I made is:

Each brand/make/model of car is different. Advice for one, does not apply to all.

 

[The Real Maverick]

I Fill till it clicks, wait 30 seconds, and do a top-off. Sometimes I can get the range over 400 miles doing that. The highest was 415. On average it's 385.

I Fill till it clicks, wait 30 seconds, and do a top-off. Sometimes I can get the range over 800 miles doing that. The highest was 840. On average it is 720.

Brothers with different mothers.

 

[oysterville]

The point I made is:

Each brand/make/model of car is different. Advice for one, does not apply to all.

Oh sorry. I must have misread your post. I thought that you were staying that it is okay to do a couple of clicks after the first one.

 

[The Real Maverick]

Owners manual for hybrid:
View attachment 176481

EcoBeast:

https://www.fordservicecontent.com/...=USA&VIN=&userMarket=USA&div=f&buildtype=web#

Moot point.
The hybrids basically don't allow any real "topping off" anyway. It's engineered out.

 

[The Real Maverick]

Oh sorry. I must have misread your post. I thought that you were staying that it is okay to do a couple of clicks after the first one.

It is from an engineering standpoint in the Hybrid. I have not looked into the EB because I don't have one.

I also said the hybrid system prevents you from topping off in the traditional sense.

It is ok because 2-3 clicks is necessary to rule out premature shutoffs. The first click tells you nothing. Sometimes it happens after 1 gallon has flowed into the empty tank. The added fuel from one or two click is minimal if the tank is full. Could be one or two gallons (100 miles) if it was a premature shut off. There's about 1 in 10 jittery pumps out there. I seem to find most of them.

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