First, what's is up with the bath tub comment?

Second, your argument that you've had over 150k miles with fillups like yours doesn't counter what I'm saying, which is that the damage (or potential) is occurring elsewhere. Your gas cap is a tight seal, so expanded gas will go somewhere when it has no room in the vent - you just don't see it. (You may smell it though.)

Besides that, your argument uses flawed logic. Its like a smoker saying that s/he's smoked for 20 years and has never seen a problem. You can't see the damage inside from your casual outside perspective.

Topping off like this can damage many things, and its really not worth the effort. I may not convince you to change your ways, but for everyone else reading this, don't do it. I suggest people read the content on following links:

http://www.epa.gov/donttopoff/
http://www.sbcapcd.org/edu/dont-top-off.htm
http://phoenix.about.com/cs/car/a/gas.htm
http://www.cartalk.com/content/eco/tips.html#3

I could go on... but I know when to stop!

 

If your "venting" then you aren't getting more miles per gallon..

Your just overfilling the tank all the way to the neck and getting extra fuel per fill up, then calculating your miles with the standard fuel tank amount.

Not worth it...

JMO

 

To add to that, the tank holds about 13 gallons. Add an additional gallon or two to the filler neck, and you're mileage per gallon calculations will probably drop.

The best way to calculate mileage is simply to reset the trip odometer after a fill up, and then at the next fill up divide the accumulated miles by how much gas you just put in the car, and always be consistent in your method.

 

My God! You're right! I will stop this immediately!

err...ummm...nah!

The funny thing is that the only reason I mentioned venting at all is that I was trying to explain that I always have the same baseline for my MPG calculations...the tripmeter starts with a full tank (REALLY full) and is reset when the tank is again full - so I know exactly how much gas I used, and when I divide the elapsed miles by this figure I know the true mileage...

Saki said: "First, what's is up with the bath tub comment?"
- HOT tub, not bath tub...a hot tub is a large recessed space which is filled with water that is heated and then, often, rapidly circulated with forced air from an electric pump. The water stays in the tub and is treated - much like a pool, only smaller and - well, hotter...My point then was that SOME people are obsessed with how they maintain their hot tubs, or their lawns, or their clothes, or their hair...I have a thing about economy and not wasting money.

As for the "Don't top off" sites, I know...which is why I make sure to vent when I am about to immediately drive enough miles to consume the overfill - which is virtually always...I have avoided the practice occasionally, on very hot days, when I know the expanding fuel may cause an issue. It takes extreme ambient heat to accelerate the rate at which surface fuel evaporates from an unsealed space.

Yikes - anywho...I am so happy to have shared that I'm encouraged by the economy potential of our cars...

 

Okay, now I understand. You have an obsession with cramming gas into your car like some people have an obsession with cleaning hot tubs. Thanks for the explanation.

Seriously kids, don't try this at home.

 

on avg i am getting between 27 and 28 mpg on a tank. however, when I am vtec happy, I am will get around 21mpg on a tank.

vtec = poor mpg = happy driver = why I got s2k

 

Very simply, when your car "pulls" it uses more gas than when it "coasts."

You get the worst mileage when accelerating from a stop, almost as bad going up a hill, a bit better on level ground, and the best when going downhill or coming to a stop (even better is coming to a stop in neutral).

The S2000 (or any "fast" car) makes getting poor acceleration mileage even more of an issue with the temptation to VTec...so, when the area in which you drive has fewer lights or stop signs, you can count on better mileage!

Of course...even at speed it is tempting to kick it in with this baby!!!!!!

 

What figure?

What are number are you dividing into your miles to get your true mileage?

 

grrnmo, what's the most miles you've gotten on one tank?

300 miles is like pie in the sky for me, 240 is more like it for around 11 gal (~22 MPG mixed driving). But I drive fast. My theory is, why have a S2000 if you're not gonna use it?

But great job if you're 380 miles per tank

 

hmmm.....IS THAT SO???

WOW!!

Stopping in neutral...

Buying an S and seeing how far you can stretch the mileage by venting the tank and driving like a ........

Sell your S..... and go buy a Prius.

JMO