You put 16 gallons of fuel in your 3? How?

These cars have a generous reserve. You should fill till the pump clicks off and leave it. Topping off tanks is unnecessary and harmful to the environment.

 

Don't over-fill your tank:

Smoke Machine
Pat Goss

A check engine light can drive you and your technician nuts, and one of the more common areas where we find problems is in the evaporative emission control system, or EVAP system as it's called in the industry. This is the system that collects fumes from the fuel tank, stores them in a vapor canister, and then injects them into the engine to be burned instead of expelled into the atmosphere.
Now these are pretty sophisticated systems, but one thing that you have to keep in mind: in order to isolate it to the EVAP system, somebody is going to have to read codes, and the next thing you have to remember is that codes do not tell you the part that has failed, it only tells you what is being affected by what has failed.
So, that means you're going to have to do some testing, and the number one thing you check whenever you have an EVAP problem is the gas cap. They fail quite frequently. Alright, next thing you're going to look for is liquid fuel in the EVAP hoses, like in this particular one, in the plastic elbow, it has liquid gas in there. That can set the code and it can also damage other parts in the system. What causes it? You cause it! You top off the tank, and when you top off the tank too much, liquid gas overflows into the EVAP system, and you've got a check-engine light and possibly some expensive repairs.But many times that won't be the case, there may be a leak. Now, how do you find a leak? Well for that you use a smoke machine, such as we have here. We've got the machine turned on, we're feeding smoke into the EVAP system, and we simply follow along the tubing and so on to see where the smoke comes out. In this particular case, we have a pinhole right here that is leaking smoke. That means that little rubber elbow is bad, it has failed due to age and road debris, different things like that. .. needs to be replaced. Now, in many cases the holes will be so small you cannot see them without the smoke. So the lesson here is to be sure before you take your car into a repair shop, you ask them if they have a smoke machine, so they can properly and effectively check the EVAP system on your car.


__________________

 

Thanks for the lecture, both of you.

You still did not answer my question. 12.8 and click then much less mileage. My 05 sp23 did not do this, filled up just fine.

 

mazda3 hatchback has a fuel capacity of 15.9 gallons, according to MazdaUSA.

top off if you want. f>ck the environment....I like seeing my fuel econ say "520 miles" till empty.

 

... just fill it up till where it ticks, its not hard why would you risk it just to see over 500 miles... point less and dumb
sometimes it'll fill up alot and sometimes not, not really a BIG deal

 

[quote author=shotdead42 link=topic=175747.msg3724562#msg3724562 date=1278896946]
... just fill it up till where it ticks, its not hard why would you risk it just to see over 500 miles... point less and dumb
sometimes it'll fill up alot and sometimes not, not really a BIG deal
[/quote]

From my earlier post (#2):

...Alright, next thing you're going to look for is liquid fuel in the EVAP hoses, like in this particular one, in the plastic elbow, it has liquid gas in there. That can set the code and it can also damage other parts in the system. What causes it? You cause it! You top off the tank, and when you top off the tank too much, liquid gas overflows into the EVAP system, and you've got a check-engine light and possibly some expensive repairs...

 

Could just be that the digital gauges in the 2010's are JUNK. Mine read absolutely empty with 4 miles left on the range computer. I filled it to the click and only paid for 11.5 gallons... with a capacity of 15.something gallons don't you think I should be closer to about a quarter of a tank?

 

I've noticed something similar with my 2010 mz3 s sport. Basically, as near as I can tell, the fuel gauge itself indicates one bar per gallon, 12 bars, about 12 gallons. When you reach empty on the gauge and the low fuel indicator lights, the onboard computer will indicate a range of 0 miles remaining. At this point, you have 2.5-3 gallons remaining. I've noticed a newer gas pump at a safeway will fill more fuel before it clicks off than an older pump at a Bradley gas station where I normally refuel. I don't know enough about the interaction between pump and tank to say what that means.

My own best guess is Mazda set it up this way so that there is no possibility to starve the fuel pump under conditions of extreme cornering/accelerating/decelerating while the gauges are indicating fuel and range. The excess also provides an ample reserve if you let your spirited driving take you and your mz3 far away from the nearest gas station.

 

[quote author=chromal link=topic=175747.msg3787607#msg3787607 date=1283740600]
I've noticed something similar with my 2010 mz3 s sport. Basically, as near as I can tell, the fuel gauge itself indicates one bar per gallon, 12 bars, about 12 gallons. When you reach empty on the gauge and the low fuel indicator lights, the onboard computer will indicate a range of 0 miles remaining. At this point, you have 2.5-3 gallons remaining. I've noticed a newer gas pump at a safeway will fill more fuel before it clicks off than an older pump at a Bradley gas station where I normally refuel. I don't know enough about the interaction between pump and tank to say what that means.

My own best guess is Mazda set it up this way so that there is no possibility to starve the fuel pump under conditions of extreme cornering/accelerating/decelerating while the gauges are indicating fuel and range. The excess also provides an ample reserve if you let your spirited driving take you and your mz3 far away from the nearest gas station.
[/quote]

I agree; I believe it has to do with leaving a generous amount in to avoid starving the pump in extreme circumstances. I had to do a very hard stop on the highway followed by a full throttle acceleration to avoid getting smashed in the rear... I had zero bars left on the fuel gauge, and the light was on for a while (wasn't worried, I knew about the generous gas light). When I lurched forward the car almost stalled as if it missed a few ignition cycles, I chalked it up to no fuel left and an accidental sloshing of what was left.

 

I have had my 11 3 Hatch with the 2.5l engine fro about a year, and I've gone 11K miles or so.
Every time I fill up, I have this problem. I drive 20-30 miles past the low fuel light nearly every tank, and I get about 10-11 gal in before the pump quits.
If I wait for the foam to recede, then pump some more, it will add about a gallon more. The longer I wait before pulling the trigger again, the more goes in.
I have gotten it to take 16.x gallons before, but I had run for longer than I wanted to after the light came on(like 50 miles or so...).

I now understand that the EVAP system can be affected, but if we have a 15.9 gal tank rating, why should we be forced to drive like we have a 12 gal tank? That's an extra round trip and change to work.

grr.

 

Theres extra room there so you can afford the luxury of going an extra 50 miles past empty. When I pump gas I let it pump as slowly as possible. Diesel is even worse.

 

If you are putting 16.x gallons in a 15.9-gallon tank, perhaps you should look under your car for gas leaks while filling it that full. The most I've ever been able to put in mine was like 14.5, and that was running about 75 miles past the low fuel light. I see no reason for being able to put in 16.x gallons in our car.

Another thing: you might be getting robbed of fuel. The pumps have to be calibrated every so often to ensure they are delivering the amount of fuel they claim (so the customer doesn't pay for more gas he's getting, or to ensure the gas station isn't "giving away" gas). Could be a matter of a gas station that hasn't calibrated their pumps in a while (which I believe they are legally obligated to do every 6 months or something like that).

As for topping off your tank and "hurting the environment", you must be one of those that believes the following poster:

 

The manual specifically states not to top off.

 

I'm pretty sure it also talks about changing oil every 3000 miles and to only have dealers do any adjustments/mods, but hardly anyone listens to that either.

Further, I HIGHLY doubt its reasoning for not topping of gas is for environmental concerns. I haven't looked, but just taking a stab in the dark. I don't argue possible damage to the car (namely because I don't know if it is true or not), but I doubt doubt it's harmful to the environment. Just my :2cents:

 

[quote author=GrifN link=topic=175747.msg4198425#msg4198425 date=1331318169]
I'm pretty sure it also talks about changing oil every 3000 miles and to only have dealers do any adjustments/mods, but hardly anyone listens to that either.

[/quote]

it does not say that actually. Whether its for the environment or just for the health of your fuel system its not recommended.

 

[quote author=E150GT link=topic=175747.msg4198427#msg4198427 date=1331318309]
[quote author=GrifN link=topic=175747.msg4198425#msg4198425 date=1331318169]
I'm pretty sure it also talks about changing oil every 3000 miles and to only have dealers do any adjustments/mods, but hardly anyone listens to that either.

[/quote]

it does not say that actually. Whether its for the environment or just for the health of your fuel system its not recommended.
[/quote]

You are correct. The 2010 & 2011 manuals specify oil changes every 5000 miles. My mistake. Regardless, I choose not to believe the hype about damages from topping off fuel, as I've always topped off (keep filling until I get a 2nd click, and then round to nearest dollar) and I've never had an issue.

 

I have heard the thing about filling the tank up, I usually it once or twice after its full. Just for the joy of having a full tank. My sisters 2011 Fiesta overflows if you click it after its full.


How far are yall driving past 0 miles? I've done 40 max, GrifN 75 miles past 0?! Wow! That is a huge reserve they hide from us.


Also for how much the gas pumps are putting out, some actually tell you if they are above or below 1 gallon when the pump says it. I saw it at one gas station and mine was below 1 gallon, I guess they have some small tolerance.

 

[quote author=h.letchworth link=topic=175747.msg4205479#msg4205479 date=1332288418]
I have heard the thing about filling the tank up, I usually it once or twice after its full. Just for the joy of having a full tank. My sisters 2011 Fiesta overflows if you click it after its full.


How far are yall driving past 0 miles? I've done 40 max, GrifN 75 miles past 0?! Wow! That is a huge reserve they hide from us.


Also for how much the gas pumps are putting out, some actually tell you if they are above or below 1 gallon when the pump says it. I saw it at one gas station and mine was below 1 gallon, I guess they have some small tolerance.
[/quote]

I've done about 75 miles past "low fuel" light. Get another 30 miles before I have no bars of fuel on my gauge, and then I've gone another 40 or so miles past that, totaling 70-75 miles. As someone stated above, I believe each bar is supposed to represent 1 gallon. 12 bars = 12 gallons (which is about how much I put in at low fuel).

 

500 miles per tank? When I fill up I hardly touch 300

 

[quote author=Stayoverjayslay link=topic=175747.msg4206562#msg4206562 date=1332440555]
500 miles per tank? When I fill up I hardly touch 300
[/quote]

Ditto.

 

Gas tank capacity

I realize this is an old thread, but I'll add my information in case it is useful to others. Initially I was frustrated with theoretically having a 14.5 gallon tank but never really knowing for sure as I usually was filling up to about 12.6 gallons, even after having only single digits left on "Range".
So I did a test. I intentionally ran out of gas. I reset my mpg and trip meter when the range hit 0, then drove it till it stopped. I had one gallon in a container in the trunk. I wrote down the mpg and trip meter readings, then put the gallon in the tank, reset the mpg and trip meters and drove to the gas station. Then I wrote down the settings that I had incurred to the station. Then I pumped until it shut off. Using all this data I could find out two important things. 1) how much gas is in the tank when the range meter says 0. How much gas does the tank hold? I found out that when the range = 0, I have 1.7 gallons of fuel remaining. I also found out that the tank holds 14.2 gallons before the pump clicks off. I used the mpg/trip settings to determine how much of the 1 gallon I had used and subtracted it from 1 telling me how much was in the tank, then added this to the amount I pumped to come up with 14.2.
I used this information to hit my personal best of over 700 miles on one tank and 50 mpg. I filled up in the morning and then topped it off by .3 more gallons giving me a theoretical 14.5 gallons in the tank. I knew I had to be around 616 when the range hit 0 to make it safely. According to the gauges I made it 707 miles @ 50.7 mpg. My calculations showed 712 @ around 49.8 mpg since the odometer is off by a bit. When I filled up it took 14.01 gallons to shut off. Since the tank holds 14.2 at shutoff (before I top it off) I had .2 gallons remaining. In other words if I topped it off by .3 again it would be at 14.31 which is .19 (rounded to .20) shy of 14.50. Hope someone finds all this useful. God bless!

 

@RustyJam, what model year and what engine do you have?
On the 2010 hatch, the fuel gauge is digital and there is also an "autonomy" indicator that's a filthy little liar When I fill the tank it says I have 840 kms to go. In reality, I never got past 550/600 (375 miles). Maybe I could've hit 650 if I had exhausted the reserve.
My engine is a 1.6 liter (gasoline) and I average about 12,5 km/l (29 mpg).
I blame the 5-speed transmission... also, I get the distinct impression that the American idea of a highway is something radically different from the European one. "Constant speed" is something we know not of.