my 08 fit owners mal. says 10.5gal. but in the 2.5 yrs an 112000 miles i've driven.i find the mal. is wrong. the tank is under car and fills from up by window. at first i'd stick nozzle in until it shut off. my mileage was 27-43mpg. then one day i pilled tank all the way from 20 miles after gas light came on, 12.3gals. so from then on when nozzle stops, i find it takes .2gal at a time letting air burp out for 2 more gals.so my take is always full and my mileage is 28-32mpg on hwy w/o a/c , with a/c it takes 5mpg to run it. i write every gal. down since i've owned it. it's my work vehicle. bad mpg is killing my, any ideas?

 

The 2007 and 2008 fuel tanks are actually 10.8 gallons with a 1 gallon reserve if I recall correctly. You may have gotten an extra half gallon in due to the air bubbles in the fuel lines.

 

take it to a dealer. however, even dealers usually don't entertain bad epa issues. but they might end up spotting the issue.

 

I have a 2007 sport and, like the O.P., I too can squeeze an extra 2 gal. into the tank after the first auto pump shutoff. It requires patience as you have to let the bubbles calm down and SLOWLY add more gas with the pump handle on the lowest setting.

Since it takes so much extra time to do this I normally don't except if the fuel price is significantly lower than my normal neighborhood stations or if I'm setting off on a trip over 300 miles and don't want to stop for fuel on the way (the extra 2 gal. extends my range by 60 miles). BTW I average about 30 mpg in combined city/highway driving at a moderate pace with the sport automatic trans just left in drive.

 

Over filling the tank in the Fit [or any contemporary car] is bad practice. There is a good reason not to. Learn about the EVAP canister it's purge and shut valves and the ECU and you'll understand.

Topping off is simply crazy. A false sense of security. I think of it the same as setting the clock ahead to be on time... just don't do it.

 

^ I agree.

Overfilling will eventually saturate and ruin the evap charcoal canister. The evap is there for emmision reasons to trap vapors not gas.





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Thanks for the advice on overfilling and its effect on the evap canister. I hadn't thought of that, but now that you mention it I'll refrain from doing this. I've only done it a few times anyway so I assume that any liquid that did get into the canister will evaporate.

 

You should be fine. Live and learn... live large and learn more ;-)

 

You just paid for 3 gallons more than the car took, it happened to me when it was 95 degrees out and threw in 12 gallons when the tank holds 13.2 and had a quarter tank. That was back in 2005 and now I just put the pump on low and when it stops I round it out to the nearest dollar.

 

Wouldn't it be no problem as long as the car was driven significantly immediately, thereby using up some of that gas in the fill hose, since the evap canister's connection to our system is way up at the fill neck? Granted, if the fuel's temp rises, it will expand and can cause issues, but let's for the sake of argument say that you are filling up at a station on your way out of town across state? (No, not CT, RI, NJ, or any of the cute little states, I mean like a 200+ mile drive)