@hendrikdupscholtz I might have cracked this issue. To sum it up the solution in one sentence: the rear alignment was way off. The car was suffering from rear wheel steering. Once the alignment was brought to spec, the car now no longer needs constant steering inputs to keep it in the lane. Here is some more on what happened:
The Chey dealer in my city has a laser 3D 4 wheel alignment machine. Till date despite 2-3 attempts and alignment that car was not right. Up to now my normal practice was that I would leave the car with the shop and collect it later. But this time I went into the shop and had a good look at what was going on in the alignment bay. What I found was that, 1) The machine had an old software which did not have the 2022 Tiggo 8 Pro data fed into the machine. The latest car they had in the machine was a 2015 Chery Tiggo. 2) They were setting up the car to the specs of a wrong model. 3) The readings displayed on the machine monitor were in degrees whereas the alignment data in the owners manual is in minutes.
As a first step I converted the alignment data from minutes to degrees so that the tech could disregard the 2015 Chery Tiggo data and follow the reading I supplied him.
In the table above, the first column is from the owners manual and the second column are the same reading converted to degrees.
A picture of the alignment reading as is without doing any adjustment
Attention is drawn the the rear data. Look at the last set of numbers (Rear Toe). Left side is -0.36 degrees while the right side is +0.34 degrees. From here we can see the rear of the car is trying to push the tail of the car out. The correct spec should be +0.083 +/- 0.16 degrees.
Then we look at the second from last display (Rear Camber). This can be seen to be (left) -1.27 and (right) -1.33 degrees. Again this number is way off from the factory spec. Correct alignment for rear camber is -0.7 +/- 0.5 degrees. The tech was able to bring the alignment of the rear of the car within specs and then moved to the front. He informed me that on this car one cannot adjust the camber or castor. The only adjustment available was toe. I find this hard to believe and requires some more digging into the front geometry to see if he was telling the truth. But that is for a later date.
The front toe reading is the top most reading on the screen. It is showing (left) -0.98 and (right) -0.42 degrees. The book calls for +0.083 +/- 0.083 degrees. The tech was able to get front toe reading within specs. Now the only thing remaining is the front camber.(second row from top on the screen). The book calls for -0.42 +/- 0.75 degrees. If we look at the right side camber, it is -0.42 degrees which is absolutely correct. However the left side camber is -0.98 degrees. Here if we factor in the tolerance of +/-0.75 degrees we can work out the range of acceptable camber angle. Based on this the camber can range from +0.33 to -1.17 degrees and still be within spec. So the reading of -0.98 degrees is within spec range but I would have been happier to have left and right camber to be equal to each other.
For now the car is driving really well and the three hours spent in the shop did not go to waste.
