Its not good to let the tank run down past a quarter tank. The space fills up with vapor and with the new recovery systems you are paying for more gas than goes in the tank. I usually round off after 2 clicks with no problems and fill up at 1/4 to 1/2 a tank.

 

And you can't even understand how idiotic your own statement is. I have a different Fit than you do, and totally different terrain. You can't possibly predict how often I refuel, since I don't have a daily commute, and only log about 6K miles in a year.

 

This is an interesting conversation...

Please rant some more; it's an interesting counterpart to my whining.

Bullet, your turn.

 

I am done, its interesting I am not really in the middle of this one and finally enjoying something for a change.

 

Sometimes I think that therapists should advertise on this site, not just Tire Rack and the like.

 

But how much gas is lost to vapor versus the extra gas burned pulling into the station and re-starting the car when you drive out? Not to mention the extra time...

 

It depends on winter/summer and out side temps. I have miss filled my 2004 Civic once and only once because I forgot to take the nozzle out after the pump stopped and put in 10 gallons when I had a third of a tank. The best time to fill is on the way to work. You have to look at it like this because after you get to a half a tank your mpg average drops faster than the time spent. Also your octane drops because the light ends are in the tank as vapor. Get a gauge and you would see what I am talking about.

 

I don't want to know why, but I suspect it's going to have something to do with vaporous light-ends and lower octane remaining in the tank, which is a horse of a different color, for sure. A putrid, decayed, horse-flesh color.

 

When the tank is full the fuel in the top half of the tank presses down on the fuel in the bottom half, compressing the little springs in the molecules. Once compressed, those molecules are ruined and don’t push as hard on the pistons. So your power and mileage drops off when you try to use the fuel in the bottom half of the tank. It’s simple physics, really. Ask anyone.

Btw, I’ve also learned that they’re now using embryonic stems cells, along with the mercury, in vaccines. And I thought autism was bad enough.

 

Cars get better MPG with more weight on board, duh. When I get to half a tank I put bags of sand in the trunk if I cant get to a gas station, and get 45mpgz.

 

Lol wut?

It's perfectly fine to run below a 1/4 tank. I run below the empty mark nearly every tank.

 

Everyone knows compressed molecules have more energy. It's the extra spring release as the chemical bonds are broken and made. So yes, I can see where driving with a full tank would give you better mileage, but not due to ruined molecules.

Which brings us back to the OP; topping off the tank is more likely to explode your car with all of the extra potential spring energy.

 

Since gas weighs about 6 pounds a gallon, I drive around with only 0.6 gallons in my tank all the time saving about 60 pounds of weight. Downside is that I need to gas up three times a day. Next I'll be filling my tires with helium to further reduce weight.

 

There have been a lot of people I've known that would disagree with you about running on a tank too close to empty... The fuel in the tank keeps the fuel pump cool. Fuel pumps tend to overheat and need replacing if there is not a sufficient amount of fuel in the tank to dissipate heat... It probably isn't as much of a problem in your neck of the woods but down here where we see temperatures over 100 degrees F over 6 months a year it is... It's been 80 degrees for most of today...

 

Honda designed a reservoir around the pump to keep it submerged with return fuel. I think you'd have to run it dry for this to be a problem

It's not a Ford.

 

Out of curiosity is this design found in both the GD and the GE? I run my GD down to fumes for AutoX and although I have had no starvation issues I had not thought about the pump...

 

dunno, here's the GE shop manual. You might try looking at a GD parts call-out from one of the websites to see if it's similar.

 

To each his own.

But I don't top off when fueling because:

A: Honda explicitly recommends against it.

And

B: I see little advantage to the relatively small addition of extra available fuel in the system that topping off might represent.

So to me it simply makes no sense.

I would say, that since I think most people do fill, and then drive X amount of miles once filling up....that the risks of overfilling past the click off point are probably very, very minimal if not non-existent.

Oregon does not allow owners to fill themselves. So I've watched attendants "Top Off" my tank, when they think I'm in the store not watching.

I never request they top off, or fill beyond shut off...but I don't freak out if they do.

In self serve States (most of the rest of the USA), I wouldn't do it....but I do think it's probably a minor, minor issue.

 

I also stop filling at first click. Main reason being, I'm usually in a hurry and couldn't care less about the marginal amount of extra gas. If I lived out in bfe with only one gas station in a 100 mile radius, maybe the extra fuel may be worth it. Doubt this is the case for anyone here.

Second reason is, if you understand how the evap system works, there is potential that you could clog the system by overfilling. Not that this happens a lot, but it is a possibility and a common enough occurrence where the manufactures recommend not filling to the rim.

Rule of thumb is, go with what the manual says.

 

They did put in a fill tank light to show it it needs gas before you dry the reservoir out, or was that to get more complaints of too much fuel left in tank.