first tank

<div class='quotetop'>QUOTE(humble @ Aug 22 2007, 09:35 AM) [snapback]500227[/snapback]</div>

Woohoo! Congrats

Let us know how your P&G practice goes.

Out of curiosity, since you are driving 90% highway, what is your average speed on those roads? Also, how many PIPs did you have on the gas guage when you filled up?

 

That is very good. It will get even better!!
My last top up worked out to 4.3L/100km or 54.7mpg(US) across town, 34km each way.

Can anyone tell me why it matters how much fuel was left in the tank prior to topping up?

 

<div class='quotetop'>QUOTE(patsparks @ Aug 22 2007, 10:38 AM) [snapback]500287[/snapback]</div>

Would you bother filling up (topping up) if you were only down 1L since the last time you filled up?

I'm guessing not. It would be a waste of time to "top up" every time you were down 1L

How about if you were down 2L? No? 6L?

Ok, at some point you are down far enough that you will take the time to "top up".

Some people seem to take this to an extreme. They want to wait until the last possible moment to "top up". Some of them enjoy the challenge of seeing how many miles they can travel on a single tank of gas (petrol?).

Knowing how much is left in the tank allows them to drive further before having to stop.

 

But I fail to understand how it makes any difference to the fuel economy.
I last filled my car with under 400km covered because fuel prices here change from day to day and week to week. Prices were down, I filled up. Put about 16 litres in from memory. Last time I filled up I had over 800km on the trip meter, it made no difference to the economy I achieved. The type of driving I did had an influence but not how many bar were left on the fuel gauge. 60mpg is 60mpg whether it was over 100 miles or 400 miles and the amount of fuel in the tank prior to topping up will be the difference between the capacity, which varies in US cars due to the bladder and the amount of fuel put in the tank.
So if the tank took 9.6 gallons the fuel in the tank was the capacity minus 9.6 gallons.

I find the facination with getting the most miles from a tank leads to over filling, fuel wastage and tank damage. One poor soul posted a pic of his filler neck almost overflowing, very proud of himself and he was told not to do that. Can you see the conflicting message? Get lots of miles from a tank, don't fill the tank right up. Don't run out either, you might damage the battery, get lots of miles from a tank though.