[cincyelement05]

We just returned home from a 320+ mile Chicago trip, and the element performed well.

The element got 24.7 mpg, a personal best. The way I measure the mpg is to fill it until it won't take any more gas, then run the tank out, and refill to the tippy-top of the tank again.

When I filled the tank, however, I was able to get 16.1 gallons into the tank, even though the manual says it only holds 15.9.

I did run the fuel tank down pretty far, about 15-20 minutes after the fuel light first came on.


Any suggestions?

 

[steamloco76]

The extra gas was probably sucked back into the pump by its vapor recovery system if it had one of the nozzles with the rubber diaphragm on it.

Note-Hondas (and Subarus) do not like to be filled to the "tippy top" past the first auto shut off of the gas pump.

Excess gas ends up in the evaporative emissions canister which is packed with charcoal to retain vapor until the engine is started-then the purge valve opens and the vapor is sucked into the intake stream and burned. Get too much gas in the filler pipe and liquid gas ends up in the canister and then it will need to be replaced-which is not particularly cheap or convenient.

For the truest mileage-stop pumping at the auto shutoff and track over several tanks (preferably re-filling before the low fuel light is on).

 

[ramblerdan]

What Steamloco76 said. Overfilling causes problems, and doesn't offer any benefit.

 

[djhotwheel]

I have been doing this for years. I have always felt I'd get a nice full tank and the needle does not move for 50 miles of driving. Now, reading this info I have gotten more than 16 gallons.
I have also drove my car until the gas marker is about 1MM past the red straight on. I estimate that I get 30 more miles when the light goes on.

Now knowing this info. Can I trust a standard gas pump to stop at the usual 13 gallons when I know 3 more gallons can get in there? Maybe just go to 14 gallons?....Hmm

 

[cincyelement05]

Almost 400 miles out of the tank

It is my wife's car, and she usually gets 240 miles out of a tank until she fills up.

She also stops at the first click.


I have to admit, this isn't my first time I have filled it to the tippy-top.


I was taught that this is one of the only true ways to measure gas mileage.


Each honda I've had, including my 93 acura integra since 2001, has gotten to tippy top fuel tank treatment.

How would you know if your charcoal filter thingy broke? Would the fuel gauge or low fuel warning light not work?

 

[Mikement]

It is my wife's car, and she usually gets 240 miles out of a tank until she fills up.

She also stops at the first click.


I have to admit, this isn't my first time I have filled it to the tippy-top.


I was taught that this is one of the only true ways to measure gas mileage.


Each honda I've had, including my 93 acura integra since 2001, has gotten to tippy top fuel tank treatment.

How would you know if your charcoal filter thingy broke? Would the fuel gauge or low fuel warning light not work?

If your evaporative canister with the charcoal filter didn't operate correctly you'd most likely get a check engine light and the code would refer to the evap system. If you let the fuel pump click off by itself (first click) that's a pretty accurate way to check mileage. Calculate how many gallons are needed to fill it up to the click every time. You can check your mileage after burning any number of gallons really. Just as an example, I burn roughly 12 gallons from when the fuel light first comes on until the fuel pump clicks. I don't like to let it run too empty or put much more in after the pump clicks.

 

[ramblerdan]

No reason to go past the first click. As long as you do it the same way every time, it'll work just as well for mpg calculation as topping it off to the last drop.