Remove the drive shaft and push the car backwards on a level surface.
See how much force it take- put synthetic lube in the rear, reconnect then try it again. You will be so surprised...


The suggestions to correct the tune up & reduce rolling resistance need to be followed...or you are wasting your time.

As far a mpg and rear end ratios...the rpm of the motor at it's cruising rpm [say 70 mph with an automatic] is where the converter's stall speed
should be just below this rpm. If you are always under the stall speed of the converter you are loosing efficiency and gas mileage.