Over filling the gas tank, is this a practice that should be avoided?

I don't fill past the first auto shut-off anymore. I used to do it when I first started driving, but only to get to a nice even $20 or $40 so that I could use cash and not have to worry about change.

On the topic of extra range, sure it gets you more miles between fills, but if you plan ahead, you can avoid being caught in a bad situation. On road trips, I usually fill up whenever we need to use the restrooms or give the kids a break, maybe every 3-4 hours. Rarely will I ever have to stop just for gas. For daily driving, I start planning out when to refuel when I get to 1/4 tank, then I just budget an extra 10-15 mins for the next time I leave the house and fill up on the way to work/on the way home. Easy.
 
There are so many reasons why you do not want to top off fuel tanks on most vehicles specifically those auto manufactures that must meet the US Emission requirements. It's not worth the possible damage you could easily cause to the fuel system. But I guess some can say you been doing it, and nothing happen, yup until it does and then you won't say that anymore! :p

I think each state has different standards of the requirements of retail gas station how the sensor regulates the fuel shut off. I know in CA it can be a PIA during summer but in Oregon it is old school pump nozzles and you can fill gas all over the side of the car and the pavement if you are not careful. But then that why their state does not allow you to pump your own fuel. With the exception if you have a modified vehicle.

And if you own a vehicle manufactured between aprox 1978-1990 you will increase the likelihood of doing damage topping of fuel.
 
ColtX-5 said:
"Nothing more useless than air in the tanks and sky above you!"

I have been told that topping off the tank (to the point of overflow) would saturate the charcoal canister with liquid in many/most/all Chrysler vehicles. The system may then be unable to extract the liquid and will set a code. The canister must be replaced. I haven't heard of another system that suffers this way. On a trip, the extra gallon I can get in the tank after the first or 2nd shut-off is well worth the trouble. Thirty miles might mean not walking.
Click to expand...
This is also an issue in the latest Gen RAV4. People who had the ‘19 RAV4 with fuel tank capacity issues were forcing as much fuel in as possible and damaging their charcoal canister.
 
sm1ke said:
I don't fill past the first auto shut-off anymore. I used to do it when I first started driving, but only to get to a nice even $20 or $40 so that I could use cash and not have to worry about change.
Click to expand...
Same. Click. Stop. It clicks for a reason is all the reason I need. ;)
 
sm1ke said:
I don't fill past the first auto shut-off anymore. I used to do it when I first started driving, but only to get to a nice even $20 or $40 so that I could use cash and not have to worry about change.

On the topic of extra range, sure it gets you more miles between fills, but if you plan ahead, you can avoid being caught in a bad situation. On road trips, I usually fill up whenever we need to use the restrooms or give the kids a break, maybe every 3-4 hours. Rarely will I ever have to stop just for gas. For daily driving, I start planning out when to refuel when I get to 1/4 tank, then I just budget an extra 10-15 mins for the next time I leave the house and fill up on the way to work/on the way home. Easy.
Click to expand...
My kind of thinking, and yes, in the good old days of cash, I'd do the same thing as you: round up to the nearest dollar after the auto shutoff to avoid having to make change. It's been many years since I paid cash for gas.
I only use plastic, so I don't care what the dollar amount is. When it shuts off, I just put the hose back and move on. I barely look at the dollar figure anymore either. Gas prices are what they are, and there's no point getting worked up about it. Fill and go. Then get home and pay off the card before interest kicks in. Life is good.
 
Buzzman12 said:
I'll never understand why people drive until they are running on empty and on fumes.
Why would you wait until you have maybe five miles of range left before filling up? Talk about creating anxiety. What is the guarantee that you will find a gas station at the last possible moment?
........
Click to expand...

A person wouldn't, unless you were in northern New Mexico and hadn't seen a gas station in ~200 miles on the backroads. OR, you were in SW Texas at Warp Factor 12 while the GPS said there was a gas station in 22 miles, only to find out it had been overrun with tumbleweeds years ago. .......

For the first story, I put 6.7 gallons in a 6.6 gallon tank!
 
ColtX-5 said:
A person wouldn't, unless you were in northern New Mexico and hadn't seen a gas station in ~200 miles on the backroads. OR, you were in SW Texas at Warp Factor 12 while the GPS said there was a gas station in 22 miles, only to find out it had been overrun with tumbleweeds years ago. .......

For the first story, I put 6.7 gallons in a 6.6 gallon tank!
Click to expand...
I always carry 2-3 bottles of Heet and I plan to use one if I get in that situation. I would add the bottle if I determined I would be short making it to the next station. I did this once and it worked.
 
Mazdiod2 said:
I always carry 2-3 bottles of Heet and I plan to use one if I get in that situation. I would add the bottle if I determined I would be short making it to the next station. I did this once and it worked.
Click to expand...

That is not a bad idea at all!

We didn't know we'd be in that situation, though. Normally, we filled up before going on reserve. That was an epic cross country with my oldest son!
 
Mazdiod2 said:
I always carry 2-3 bottles of Heet and I plan to use one if I get in that situation. I would add the bottle if I determined I would be short making it to the next station. I did this once and it worked.
Click to expand...
How did you know whether you needed it?
 
The one time I used a bottle there was a noise from the rear when I started ( cavitation) then the engine stopped. I looked at the gauge and realized I'd forgotten to get gas. I poured a bottle in the tank and jumped on the bumper to mix it and drove about a mile to the nearest station.
 
How do you jump on the bumper of a CX 5?

Anyway here in Colombia if it clicks at say $47.600 pesos I tell the attendant $48.000 to avoid coins. It's only a very slight overfill.
 
On this subject I was guilty of overfilling the tank last year. IIRC, it seems that I managed to put around 15 gallons in by slow feeding after the first shutoff. Thinking I had been underfilling the tank all along, I thereafter continued to fill as much as possible. That is until one time where I used about 6 gallons (going by miles driven since last fill-up) the pump shut off after 1 gallon and would shutoff a few seconds after every attempt thereafter. And there was a bunch of attempts. This was at a pump and station I regularly used. Same thing at another gas station.
Now the freakout starts. What if it happens again while on a trip and need a fill-up and it'll only take 1 gallon. Crawled under the car to look for damaged anything related to fuel lines and tank. Didn't see anything. Eyeballing schematic shows flapper valve in tank where fuel filler tube connects. Maybe flapper valve sticking. Oops, have to remove tank to access flapper valve. Now what?
Problem disappeared after running tank below 1/4 and stopping at first pump shut-off when filling. Now it's a short squeeze after first shutoff. Don't want to repeat the adventure whatever the cause was. Don't know if this is particularly relevant but wanted to share the experience.
 
Wife overfilled the Volvo once. She would start the car and it would shut off. Start, shutoff. Start, shutoff. She finally got it to stay started. Drove straight to Volvo. NPF. Then they ask "You didn't keep topping it off by any chance?"
Uh...
/edit/ Sorry, I assume everyone knows NPF = No Problem Found
 
So there you have. While it's been explained here, and even by automotive engineers, there are still a few that say, "well, I've never had a problem" and hence will continue with their practice of overfilling. I've never had my house catch on fire, but I'm still not leaving an electric blanket plugged in 24/7 without regard to energy cost) just to it's warm when I'm ready for it.
 
It's right in the owners manual:

"Do not continue refueling after the fuel
pump nozzle shuts off automatically:
Continuing to add fuel after the fuel pump
nozzle has shut off automatically is
dangerous because overfilling the fuel tank
may cause fuel overflow or leakage. Fuel
overflow and leakage could damage the
vehicle and if the fuel ignites it could cause
a fire and explosion resulting in serious
injury or death."
 
7eregrine said:
Wife overfilled the Volvo once. She would start the car and it would shut off. Start, shutoff. Start, shutoff. She finally got it to stay started. Drove straight to Volvo. NPF. Then they ask "You didn't keep topping it off by any chance?"
Uh...
/edit/ Sorry, I assume everyone knows NPF = No Problem Found
Click to expand...
We call it NTF at work. Trouble.
 
Please log in or register to reply here.

Similar threads

cx5boo333
Gas Tank Heat Shield Drilled Through
2
Replies
22
Views
2K
Ranman57
Ranman57
N
Lower gas tank capacity
Replies
10
Views
1K
clownshoes2
C
B
Considering a new CX-5
Replies
7
Views
2K
Martyd
M

Latest posts

Back