Turbo diesel fuel saving idea/question? - Page 2 - Fuel Economy, Hypermiling, EcoModding News and Forum

nubbzcummins · 08-03-2009, 11:46 PM

All of my tanks are filled to the same level, at the same station, with the same pump every time. I fill to the brim for consistency. How is this not valid?

ConnClark · 08-04-2009, 01:05 AM

Quote:

Originally Posted by nubbzcummins

All of my tanks are filled to the same level, at the same station, with the same pump every time. I fill to the brim for consistency. How is this not valid?

Air bubbles in the tank. I get over half a gallon variance from tank to tank taking the same measures.

TEiN · 08-04-2009, 03:39 AM

Quote:

Originally Posted by ConnClark

Air bubbles in the tank. I get over half a gallon variance from tank to tank taking the same measures.

I don't know about getting a half-gallon variance due to air bubbles in the tank, but for me, it still wouldn't matter. I do my fill-ups the same way, right to the very brim each time, same station, same pump. If I go 685 miles on a tank, and put in 38 gallons, I get 18.0mpg. If I suffered from massive air bubbles in the tank and could have actually fit in an extra half gallon of fuel, then I would have only actually gotten 17.8mpg. 17.8/18.0 = 99% I think that's close enough, especially when I don't believe in half gallon bubbles.

nubbzcummins · 08-07-2009, 09:48 PM

Even tho there are air bubbles in the tank/fuel they will be consistent as long as you fill up at the same rate with the pump every time..........which I do.

TEiN · 08-08-2009, 03:06 AM

Quote:

Originally Posted by nubbzcummins

Even tho there are air bubbles in the tank/fuel they will be consistent as long as you fill up at the same rate with the pump every time..........which I do.

Good point!

ConnClark · 08-10-2009, 01:51 AM

Quote:

Originally Posted by nubbzcummins

Even tho there are air bubbles in the tank/fuel they will be consistent as long as you fill up at the same rate with the pump every time..........which I do.

Not true. When you fill it to the brim the air bubbles that gurgle out of the tank are what determine the final rate at which fuel flows into the tank. There is no way to get the gurgling to be consistent.

Even if find a way to to fill it the same each time you would still have too much variance in the road travel draw any valid conclusions with just one tankfull.