When I was getting 6 mpg with my old BIG horse power motor the problem was: Having to stop every 75 miles for gas! Man that got old, not to mention with the high compression needing to run 'race gas', which you could never find on a trip! My new motor gets 11 to 12 mpg and is much more streetable (pump gas), the additional cruising range is a real plus and makes a solid case for:
1. 42 gallon tank if you don't care what your mpg is.
2. MPG consideration when you spec the motor.
Now it's your call which way to go.
