The One Euro is one cool looking tool. Lets look at the numbers a bit:
The Leaf battery pack holds 24,000 watts. FYI, 24,000 Watt-Hr is 2/3 a gallon of gas. The Leaf goes 99 miles for 2/3 x $4 = $2.68.
However, for that $2.68, the Leaf goes 99 miles.
Leaf Efficiency: 24,000 Watt-Hr / 99 miles = 242 Watt-Hr per mile.
The Leaf needs 242 Watt-Hr to go one mile.
At $1.32/$4 The One Euro uses about 1/3 gallon of gas to go 62 miles.
1/3 gallon of gas is 11,880 Watt-Hr
One Euro Efficiency: 11,880 Watt-Hr / 62 miles = 162 Watts per mile.
242/162 = 1.5
So, the One Euro is actually about 1.5 times more efficient than the Leaf.
EVsRock!
http://www.evsroll.com 
