This is one thing i have checked.I have never let it go past 1/2 tank.....cause i DO NOT want to know how much it will cost to fill from empty,seeing it cost me roughly 60 bucks,depending on the day of the price,to fill it from half to full!!!!
But i average close to 150 kilometers on a half a tank in my '06 F-150.

 

You do know it doesn't matter if you fill up half a tank or a full tank, your still using the same amount of fuel? Ouch to 150km to a half tank. I get almost 300, I think you may need to look into a tuneup, thats some pretty crappy mileage

 

I would actually imagine you would use more fuel since its hauling more weight. Its probably minuscule though. I do understand the reasoning behind it though

 

Haha good point. I get the reasoning too.

 

Really!!I was in at the dealer on Friday to get my F-150 flashed as i added cruse control as it didn't come with it,and my buddy said that my truck has'nt had the lastest updates done to it,so he did it while we were already plugged in.I always thought it was hard on fuel considering my '98 F-150 extended cab STX with the 4.6,and 4 speed auto got close to 600 kilometers to a tank,but this '06 really made me wonder?!!?
But anyways,i fill her up weekly regardless if i use a quarter tank or half.Undr half scares me LOL!!

 

hopefully the new updates helps her get a lil better mileage! one thing that makes a huge difference is air pressure.. Blew my mind how much the air pressure in your tires will throw off the mileage

 

Haha aint that the truth. I actually watched the mythbusters episode today where they checked out tire pressure vs fuel efficiency. Inflating your tires 15% over mfg recommended spec got something like 5 or 6% better. Underinflating by the same was about 4 or 5% worse. It made more of a difference than I thought it would

 

Oh wow, didn't know it would tamper with gas mileage that bad. I'm gettin out there now and checkin mine ha.

 

My truck has the 30 gallon tank, when I filled her up she hasn't taken more than 88-90 litres, which is roughly 26 gallons. That would leave about 4 gallons when the low fuel light came on.

Maybe I'll have to check my air pressures, I've been getting about 250-280km to a half tank.

Sean

 

According to my gryphon cs I get 17.4 average city