It is pretty simple to figure out.

Take a new car out w/a mileage indicator in it.

Drive a steady state of MPH in top gear, level ground, note the MPG, then downshift it one gear down & manitain the same MPH,, watch the RPM go up & watch the MPG go down, simple enough.High RPMs = worse gas mileage. \:D

Keep those RPMs down & enjoy the quite & better mileage ride.

MBHD


12 port SDS EFI