Never again will I do this...

Today I went to my NJ nearby gas station and the price per gallon was $2.95.
When the pump clicked off I asked the attendant to put in extra....brought it up to an even number by adding $1.15 more fuel.
Since coming home I read how this is a bad practice and could lead to a costly repair. I will never do that again.
Yet, I'm hoping I did not already do damage.
Fast facts....
I have a 2016 Mazda CX-5
Since the price for one gallon was $2.95 and I had the attendant (NJ) add $1.15 more...well then the more that was added was less than 1/2 a gallon more compared to after the pump initially clicked off.
( $2.95 divided by 2 = $1.47 )
What do you think?
I'll be ok?
 
I think you will be okay. I've sometimes topped off up to a dollar (when gas was around ~$2), so more than half a gallon that time. Though I agree that aside from this one-time, try not to do this. If you're really worried, drive around a few extra minutes to burn off the extra fuel.
 
I’ve been driving for 51 years and at almost every fill up, I try to squeeze in as much gas in the tank as possible. I have never had any problems. I have a 2021 CX-5 and have only filled it about 6 times, but have filled it as full as possible at least 4 of those fill ups without consequences. I have always read that you should NOT top off your tank, but sometimes I wonder if it isn’t to appease the pollution police who don’t want you to spill a drop of gas on the concrete at the pump.

I personally would like to know if any tank toppers like me have ever had any problems associated with the practice.
 
You're fine. You get a free pass on the first time, second time you'll get a verbal warning from mazda customer service.



Lol jk I've topped off multiple times too without any ill effects.
 
Found this while doing a little searching:

Lawrence Huddleston, owner of Hud's Auto Service in Lubbock, Texas, says gas topping can damage your car's vapor collection system, designed to reduce harmful emissions.

Joel Carruso, owner of Caruso's Auto Repair in Schenectady, N.Y., adds that these systems manage fuel vapor.
Overfilling the gas tank can cause liquid gas to enter the charcoal canister, or carbon filter, which is designed only for vapor. Gas in the system can affect your car's performance by causing it to run poorly, and damage the engine, he says.

"When we overfill the tank, it sends all of the excessive fuel to the evaporation/charcoal canister and kills the life of that canister," Carruso says.

I don't top up personally.
Paying with a credit card all the time means I don't worry about rounding up. No point.

Cheers all.
 
Mostly you can get away with it, but it can cause problems with the vapor recovery system. How big a problem varies by how often you do it, how aggressive you are, and how susceptible your particular vehicle is.

You’re probably fine, but I’d avoid it, or at least only do it once. There are lots of things cars tolerate (e.g., driving a cold engine hard) that cause no immediate problem, but take their toll long-term.

- Mark
 
I think you will be okay. I've sometimes topped off up to a dollar (when gas was around ~$2), so more than half a gallon that time. Though I agree that aside from this one-time, try not to do this. If you're really worried, drive around a few extra minutes to burn off the extra fuel.
Yes I got lucky and my wife wanted to go someplace 17 miles north of us. So just when I needed to go out and drive I had the perfect reason to do so.
After 34 round trip miles of driving I am cautiously optimistic that all is well.
 

I personally would like to know if any tank toppers like me have ever had any problems associated with the practice.
I used to squeeze in as much fuel as possible when I fill up the gas to my vehicles for many years. But my 1998 Honda CR-V with about 150K miles few years ago got a CEL complaining the fuel charcoal filter canister been saturated, and the shop manual says it needs canister replacement. I checked the price (currently $306.55 MSRP) and decided to wait and see. Luckily after several fill-ups with the practice of stop-fueling after the first auto shut-off on the fuel gun, the CEL went away and it has never come back since I changed my fill-up practice. Now I don’t try to put too much fuel in after the first auto shut-off on the fuel gun.
 
It is a fact that over-filling modern gas tanks can result in damage to the evap system, sometimes requiring very costly repairs. How sensitive the CX-5 is to this I do not know.

Gotta LOL when I read statements like “I’ve done that for years and never had a problem!”. Reminds me of a former neighbor who was pushing 70. He loved saying “I‘ve been smoking 3 packs of cigarettes a day for 45 years and I don’t have any lung cancer!”. Yeah, no risk there...
 
Lol it’s weird because in Oregon they have someone to pump your gas and it’s against the law for them to fill after it stops
 
Lol it’s weird because in Oregon they have someone to pump your gas and it’s against the law for them to fill after it stops
Well in NJ the attendant will do it if you ask nicely. I have no idea about any law or even guidelines.
I learned a lot here on this forum earlier today.
 
I’ve been driving for 51 years and at almost every fill up, I try to squeeze in as much gas in the tank as possible. I have never had any problems. I have a 2021 CX-5 and have only filled it about 6 times, but have filled it as full as possible at least 4 of those fill ups without consequences. I have always read that you should NOT top off your tank, but sometimes I wonder if it isn’t to appease the pollution police who don’t want you to spill a drop of gas on the concrete at the pump.

I personally would like to know if any tank toppers like me have ever had any problems associated with the practice.
I personally have had a problem associated with this practice with my MX-5. It has a small tank and the roads we travel in it are not dotted with service stations. Thus for the two years I owned a used NB, and for the first three years that I've had my NC I always filled the tank until I could see fuel.

One day following a fill up the check engine light came on so off to the dealership I went. "We found fuel in your gas tank air pressurization pump. You haven't been overfilling your gas tank have you?" It was a 700$ purely preventable repair. Now I only fill to the auto shutoff on all my Mazdas.

Brian
 
I personally have had a problem associated with this practice with my MX-5. It has a small tank and the roads we travel in it are not dotted with service stations. Thus for the two years I owned a used NB, and for the first three years that I've had my NC I always filled the tank until I could see fuel.

One day following a fill up the check engine light came on so off to the dealership I went. "We found fuel in your gas tank air pressurization pump. You haven't been overfilling your gas tank have you?" It was a 700$ purely preventable repair. Now I only fill to the auto shutoff on all my Mazdas.

Brian
See my hope is that since you did it repeatedly, and I only did it yesterday and will never do it again....well hopefully I learned in time.
 
I have overfilled my CX 5 to the point of overflowing a couple of times by accident. Same with my previous vehicle. I have never had a CEL come on. As others have mentioned, it is a practice to be avoided.
Each time it was because I had paid in advance and over estimated the amount of fuel needed for a fill up. I didn't want to have to go back inside the shop and wait in line to get my $1 change.
 
I have overfilled my CX 5 to the point of overflowing a couple of times by accident. Same with my previous vehicle. I have never had a CEL come on. As others have mentioned, it is a practice to be avoided.
Each time it was because I had paid in advance and over estimated the amount of fuel needed for a fill up. I didn't want to have to go back inside the shop and wait in line to get my $1 change.
Thank you!
 
I personally would like to know if any tank toppers like me have ever had any problems associated with the practice.
Same as you, been driving over 35 years, always squeeze every drop I can in the tank topping up an extra gallon or more till it's up in the filler neck. Never a single problem. I keep cars long term as well. I also most always run about every drop out of them (well, except aircraft lol) before refueling.

One danger that comes to mind that this practice puts me at risk for is in the case of a collision in those first miles there is fuel in the filler tube above the tank that isn't as protected as fuel in the tank I imagine.

This has been my long-term experience.
 
We had a 92 ford explorer and over filling it caised the charcoal caniter to get saturated as stated above. I worked for ford so they warrantied it. The mechanic said do NOT add only a couple pennies after the pump clicks off or it will happen again.
 
Same as you, been driving over 35 years, always squeeze every drop I can in the tank topping up an extra gallon or more till it's up in the filler neck. Never a single problem. I keep cars long term as well. I also most always run about every drop out of them (well, except aircraft lol) before refueling.
You've been lucky.
Running the tank to empty is not always a great idea either.
Besides creating running-out-of-gas anxiety, running an empty tank leaves you more susceptible to water vapour forming in the tank.
It can also shorten the life of the fuel pump, as the pump is submerged in the tank. It is lubricated by the gas, so running the pump with little or no gas in the tank exposes it to long term damage.
I had to replace the fuel pump in an older Chrysler minivan, partly because I ran the tank dry all the time. Now I fill up my vehicles when it's down to a quarter tank.
 
brought it up to an even number by adding $1.15 more fuel.
Since coming home I read how this is a bad practice and could lead to a costly repair. I will never do that again.
Yet, I'm hoping I did not already do damage.
I'll be ok?
Is this the first time you've every put fuel in a vehicle?
Of course you will be OK.
You only added 1.5 quarts (0.39 gallons) of fuel after the pump clicked off.

All gas station pumps are different, pump fuel at different rates, 'click off' at different rates, ect.
The gas station next door could have easily put in that extra 1.5 quarts before the first 'click off'.

You could add an extra 0.39 gallons at every fill-up for the next 100K miles and have no negative impact.
 
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