Firstly you should know what figures you have been quoted. Are these figures on the wheels or figures off the crank.?
There is always a loss through the box and the diff. In the Auto box the losses are higher than through a conventional box.
The car gears down very easily, that means that the torque converter in play at all times and that affects the torque measurements.
It becomes difficult to maintain revs and load, and you need to do that in order to get proper readings.
If these are the results on the wheels I would not complain.
But it is of course not a V8!
