Regarding transmission chain, still a little suspicious why the manual Plus Four has engine mapping that significantly reduces torque compared with auto version.
I recall something said along the lines that the clutch and gearbox cant take the full torque of the engine, whereas the autobox can. I may be wrong, but it stuck in my mind.
Going back to Alistair's comment, modern turbo petrol engines have so much low end torque that the ca be "laboured". The AMG 63 4L V8, in comfort mode, rarely gets above 2000 rpm, yet it is happy to rev to 6500. As they say "The torque curve is synonymous with good drivability: the maximum value of 650 newton metre (480 ft lbs) is on hand in a wide range from 1,750 to 4,750 revolutions. So, like a diesel, it doesn't need to rev, although it can.
I ysed to love engines that reved sweetly. and that had to be kept "on the boil", but those days are gone...
