What the worst that can happen?

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aaronrules

aaronrules

Coolest person you know!
10 Year
Joined
Apr 6, 2012
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120
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Location
Greenwood, AR
So for grins and giggles, I reeeaaallllyyy topped off my truck today. From first click to seeing gas in the gas hole, I got an extra 3.6ish gallons. My questions are:

1) What's the worst that can happen by doing this? Or anything else I should know before making this my usual?

2) Have any of you done this before? How much extra were you able to get?

You guys are awesome. I am super glad that I ask stupid questions and get real answers from you guys...I just help being stupid sometimes. This is probably a very obvious and easy question to answer, but again....I'm dumb.
 
You can mess up the charcoal canister overfilling on the later 100's for sure.
 
Did you get a normal fill amount (based on miles driven and historic mpg) before it clicked off PLUS 3.6g? Just counting from when the pump clicks isn't a reliable, or even a constantly repeatable, method. I argue that with one of my employees who often tells me that he gets 14mpg when he fills up (the next guy will get 8 because he starts partially empty; van normal is 10.5 in all conditions). I only noticed why when I was with him and we drove off after he put 15g in an empty 25g tank. He said "Pump shut off. It was full". Yep, needle did;t even make the 3/4 mark.

If you doubt that, go fill the side tanks on a box truck until it clicks. I bet you'll get an easy 10g more.
 
I'll meniscus fill ups only on highway trips where I know I'll burn that first half gallon matting the go pedal on the on ramp and up to or past cruising speed to merge with traffic. LOL. Probably doesnt burn that much but it's probably a measurable amount.

After the first click, usually at 21 gallons even, I can only put another gallon, very rarely 1.5 gallons in before shes ready to puke. 21 gallon fill is when I'm burried on E. Usualy 30-40 miles after the low fuel light.
 
@AMGAndrew That seems odd to me unless they changed the tank size between years, because my 01 LX470 has a 26 gallon tank, and I'll put 25 gallons in when I run 40-45 miles past the empty light.
 
Since 2003 the charcoal canister was move to the rear near gas tank from the engine compartment. We've seen many story's of issues of vapor lock, gas smell & fuel leak when topping off with these. It's generally associated with ascending mountain roads right after topping off on hot days.
 
@ReallyACruiser I had always thought it was 24 gallon capacity. The Google says 25.4. All I know is low fuel light comes on at about 300 miles and I fill up shortly there after. Figured that if Im squeezing 22.5 gallons into a 24 gallon tank, I was running it pretty low. Guess I always had more of a buffer than I thought.
 
I never had an issue until I topped mine off, 2,000 miles from home.

It stalled and then wouldn't start and I will never do it again. If I needed the extra few gallons I'd carry it on the roof.
 
Check your OM, the one's I've seen 98-02 state 25.3 to 25.4 gal.
 
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I've gotten 401 miles on a tank and could have gone to 430 miles. That's 16.97 MPG US.

With my pre 2003, which has charcoal canister high and up front. I've always top the tank then let rest a few seconds after auto shutoff, then pull trigger again, then repeat on flat ground or slight nose down attitude. I the most I've every gotten in a tank is 24.30 gal. Drawing down to only 1 gal remaining is not the best practice for health of fuel pump, especial on hot days.

Tip: The low fuel tank light comes on at a point that the fuel pump is still safely submerged for cooling.
 
Greenbean said:
I have a 2000....

Would love to fill till I see gas in the filler neck but then that throws my Scan-Guage data out the windiw, :bang:
Click to expand...
Why what happen to data?
 
The practice of topping off the tank has been debated many times. I'm amazed (but probably shouldn't be) by the number of folks who either don't read or don't believe their owner's manual where it very specifically says to not do that due to possible damage to the emission system. Parts for these trucks can get spendy; why risk long term damage for the sake of a few extra miles per tank?

Big mea culpa on this post. I mixed up the 200 and 100 owner's manuals and the only reference I can find in the 100 owner's manual is a separate single page insert with a caution about not continuing to fill after the first pump click. It is not in the main part of the 100 manual. The 200 manual does specifically warn against it. Oops.
 
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If that's too full then what is the correct fill level guys?

I think it's fine. If you run the pump on slow until it stops you're going to be like 2" below the filler. If AAron thinks another 3.6 gallons went in then I would say you've just been leaving it 3.5999 gallons too low. It can't be a 3 gallon difference. So many of these truck have slow fillers that I think relying on the pump shut off will give drastically different fill volumes.

I think if you stood there topping it off for a long time i.e. let it drop-top it off-let it drop-top it off-etc-etc then you will eventually fill the evap system with fuel and maybe cause an issue. If you just top it off and drive away then I don't see how you'll get much fuel into the evap system, that little column of fuel at the top of the filler should get burned off pretty quickly as you drive away.

Of course I have a '99 with the evaporator mounted up high and have never had any of the evaporator gurgling/vapor locking/fuel spraying adventures that many of you with later trucks have had. YMMV.
 
Not directly related: Any knowledge of relocating charcoal cannister from back to engine bay on 2003+ models?

Also, I have read (don't remember if here or on F transit forum) that the station pump systems have an auto return feature that routes overfilling back to the underground tank. Makes sense to me but I don't overfill so never see and overflow situation.
 
Get outside said:
Are you saying you're getting 300 miles on a tank?
Click to expand...
300 highway miles when the light comes on, give or take, and I'll run to 330-340 before getting uncomfortable and fuel up. Usually 21 gallons at the first click and squeeze another gallon for a total of 22. 330/22=15mpg. I think that's in line with what most people get. I also cruise above the speed limit a little so thats not helping things.

So at 22 gallon fill ups, I still have 3 gallons in the tank and could push to 350-60 but thats way past my comfort limit, especially with the family along for the ride. Or I could slow down a bit... :steer:
 
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