DangerBird,
I contacted the Tiggy company and they said it was only in Litres and not gallons, but on their first page on information it says... Flight time remaining at current economy / litres left / gallons left. It also lets you know how much flight time you have left. There are 2 buttons in the back that let's you make adjustments. Let's say you know it takes 2.5 gallons to get from point A to B and it shows 2.48, then you can adjust it and it will be fine from then on. Go to MEMBERS up top and double click the member All_In. I don't know if he is a teacher, professor or what but he has his class working on a fuel gauge. It's kind of like the Tiggy. He's setting it up so you can put in the amount of gallons your starting out with. It keeps you up to date on how much time and gallons are left. He said it would be extremely cheaper than anything out there, BUT, it won't be out till next year. I bought a dowel rod and took a container that holds 64 ounces (1/2 gallon). I used water. I would pour that into my fuel tank then put in the dowel rod pull it out and marked the water level with a dot. The next time I poured another 64 ounces I put a line. The lines represented a gallon and a dot represented 1/2 gallon. Everytime I put the dowel rod in pulled it out and marked a line or dot I would use the hair dryer to dry the dowel to have it ready for the next pour. I hope any of this helps.
Ernie
