70 MPG downhill with the wind in your back. Most real life reports at real speeds got 4.4-4.6l/100 kms HWY. Anything past 110 kms/hr gets significantly less fuel mileage, to the tune of 5.0-5.5l/100kms. If you're 6'4" you should still be able to fit in there, ... Login to read more.