Riding around last night I felt the bike start to cough in its search for fuel. I realized that it was time to switch to reserve and find a gas station. I didn't think anything of it and just kept on riding. I pulled into the gas station and filled up. I went to take note of the mileage so I could enter it in at http://www.mileagetracker.org I then went to hit the trip reset when I saw 255 miles. I was confused for a second because that's the highest I had seen it when I was forced to go into the reserve. I looked back at the pump and saw 3.347 gallons of fuel pumped for a total of $13.16. So 255miles / 3.347 = 76.19 Miles Per Gallon!! I think we figured the route to be just around 650 miles. If Casey and I can keep that average up for the trip we will use 8.5 gallons of fuel each way.
Just to compare if we took the Miata we'd average about 28mpg which would be 23 gallons of fuel each way. The RX8 would probably keep us around 19mpg which comes out to 34 gallons of fuel.
Bikes*: 8.5 Gallons of fuel x 2 bikes = 17 Gallons Average cost of 4.10 a gallon = $69.7
Miata**: 23 Gallons of fuel Average cost of 4.30 a gallon = $98
RX8**: 34 Gallons of fuel Average cost of 4.30 a gallon = $146.2
*87 octane fuel
**RX8 and Miata must run at least 91 octane which is the cause of the higher average price