"Miles until Empty" not accurate after...

[SteveBrickNJ]

Soon I have to travel to Virginia from NJ in my 2016 Mazda CX-5.
I stopped in at my local WaWa gas station to fill it up even though I was above 3/4's full.
The pump shut off after it put in $4.85.
Then to really top off the tank, more fuel was squeezed in... making the final amount I owed $6.03
So...
I drive away and the fuel dial is pinned but as I look at the dashboard it displayed "298 miles until empty".
Again, since I have a 2016 Mazda CX-5, from experience I know that I've seen that display show a number as high as "400 miles until empty".. Even if the pump clicks off and nothing more is squeezed in it will normally display something like "360 miles until empty"
What do you think is going on?
Was so much fuel squeezed in that it messed up whatever technology there is to accurately display how many miles until empty?

 

[yrwei52]

Soon I have to travel to Virginia from NJ in my 2016 Mazda CX-5.
I stopped in at my local WaWa gas station to fill it up even though I was above 3/4's full.
The pump shut off after it put in $4.85.
Then to really top off the tank, more fuel was squeezed in... making the final amount I owed $6.03
So...
I pull away and the fuel dial is pinned but as I look at the dashboard it displayed "298 miles until empty".
Again, since I have a 2016 Mazda CX-5, from experience I know that I've seen that display show a number as high as "400 miles until empty".. Even if the pump clicks off and nothing more is squeezed in it will normally display something like "360 miles until empty"
What do you think is going on?
Was so much fuel squeezed in that it messed up whatever technology there is to accurately display how many miles until empty?

Don’t believe some extra fuel you squeezed in has anything to do with low number displayed on “Distance to Empty” comparing to any other of your fill-ups. It could be a one-time software glitch, or if could be the gas quality from that WaWa gas station which disrupted the resistance of fuel sending unit.

I’d always stick to top-tier gas to avoid any possible (long-term) ill effects against fuel sending unit which is submerged under gasoline in the fuel tank all the time.

 

[murky]

Don’t believe some extra fuel you squeezed in has anything to do with low number displayed on “Distance to Empty” comparing to any other of your fill-ups. It could be a one-time software glitch, or if could be the gas quality from that WaWa gas station which disrupted the resistance of fuel sending unit.

I’d always stick to top-tier gas to avoid any possible (long-term) ill effects against fuel sending unit which is submerged under gasoline in the fuel tank all the time.

I think the blame it on the janky gas hypothesis is weak.

 

[yrwei52]

BTW, I’d never try to squeeze in too much fuel during the top off while pumping the gas. Doing so not only it’ll have high risk of spilling the gas, but also it may saturate the fuel canister which is an emission device for fuel tank. And it’s very expensive to replace if it ever gets damaged.

For me, 3 auto stops on fuel gun is the most I’d do during the top off to the fuel tank.

 

[yrwei52]

I think the blame it on the janky gas hypothesis is weak.

You never know. Sometimes one tank of bad gas may be ruining many things. As the “long-term” ill effect I mentioned above with WaWa gas (or non-top-tier gas), ask me how I know.

 

[CarpeDiem]

I think that it may be due to the OP’s most recent mpg prior to refueling. The ‘puter uses the latest mpg to calculate the MTE, if he displayed a lower mpg this time versus the last time he fueled up, then the MTE will have to be lower.

 

[SteveBrickNJ]

I think the blame it on the janky gas hypothesis is weak.

Correct. I've used Wawa gas in multiple vehicles for 12 years.
It's quality gas!

 

[SteveBrickNJ]

I think that it may be due to the OP’s most recent mpg prior to refueling. The ‘puter uses the latest mpg to calculate the MTE, if he displayed a lower mpg this time versus the last time he fueled up, then the MTE will have to be lower.

Do you think I'm gonna be fine? I've topped the tank before without any issues.

 

[meow_man]

.......

Do you think I'm gonna be fine? I've topped the tank before without without any issues.

I used to top the tank on my older vehicles. The last several new vehicles we purchased all specified not to top the tank. It can damage the charcoal emission filter.

"Topping off your gas tank can cause pressure to build in the tank and flood the carbon filter vapor collection system, only meant for vapor. Subsequently, this overflow can affect your car’s performance and could possibly damage the engine."

 

[SteveBrickNJ]

BTW, I’d never try to squeeze in too much fuel during the top off while pumping the gas. Doing so not only it’ll have high risk of spilling the gas, but also it may saturate the fuel canister which is an emission device for fuel tank. And it’s very expensive to replace if it ever gets damaged.

For me, 3 auto stops on fuel gun is the most I’d do during the top off to the fuel tank.

I want to mention that based on your post here I will NEVER put in more than a few cents extra again. I googled the topic and read about how bad this practice can be.
Yet since gas at WaWa today cost $2.95 for one gallon...... and I put in $1.15 more (actually the attendant did...in NJ we are not allowed to pump our own gas)....then the attendant added less than half a gallon after the initial click off Today's price ($2.95 divided by 2 = $1.47.....so yup...less than half a gallon was added)
Please Lord let me not have caused a need for an expensive repair!!

 

[yrwei52]

I want to mention that based on your post here I will NEVER put in more than a few cents extra again. I googled the topic and read about how bad this practice can be.
Yet since gas at WaWa today cost $2.95 for one gallon...... and I put in $1.15 more (actually the attendant did...in NJ we are not allowed to pump our own gas)....then the attendant added less than half a gallon after the initial click off Today's price ($2.95 divided by 2 = $1.47.....so yup...less than half a gallon was added)
Please Lord let me not have caused a need for an expensive repair!!

I wouldn’t worry too much about topping off too much fuel just a few times, but just don’t do it too many times. Like meow_man said above, I used to squeeze in as much fuel as possible when I fill up the gas. 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 ($250+ ?) and decided to wait and see. Luckily after several stop-fueling practice after the first auto shut-off on fuel gun, the CEL went away and it has never come back. Now I don’t try to put too much fuel after the first auto shut-off on fuel gun.

 

[SteveBrickNJ]

I wouldn’t worry too much about topping off too much fuel just a few times, but just don’t do it too many times. Like meow_man said above, I used to squeeze in as much fuel as possible when I fill up the gas. 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 ($250+ ?) and decided to wait and see. Luckily after several stop-fueling practice after the first auto shut-off on fuel gun, the CEL went away and it has never come back. Now I don’t try to put too much fuel after the first auto shut-off on fuel gun.

I'm CAUTIOUSLY optimistic that I'm ok. My wife wanted to go somewhere 17 miles to our north. I just got home after a 34 mile round trip and the gas needle went from to the right of F and now sits on top of F. The car drives / feels normal.

 

[Conrad 16.5]

I think that it may be due to the OP’s most recent mpg prior to refueling. The ‘puter uses the latest mpg to calculate the MTE, if he displayed a lower mpg this time versus the last time he fueled up, then the MTE will have to be lower.

This ^^^^^^

Plus the car doesn't know anything about the 'extra' gas that might be pumped in and filling the filler tube. At some point the sensor in the tank sees full and no amount of 'extra' gas will be seen by the system.

 

[ColtX-5]

Don't be a neurotic snowflake (but I repeat myself).

You won't kill the car, or Evap canister with a few top-offs to the top of the filler neck. Most times I don't want to spend the time to fill it to the brim, but I have done it to every car I've had since 1975 (and the family's cars before that). NONE have ever had to have the evap system serviced. Only Chrysler products have ever been stated as susceptible.

Distance to empty varies based on the previous tank's mileage. No big deal.

 

[SteveBrickNJ]

DONE.
Take Care Everyone