Then disable centering spring and set the force to 0%
In LFS...
Wheel Turn Compensation: 0.00
Force Strength: 90%
Then look under the steering tab on the setup screen of the car you're driving, and adjust the controller wheel lock to match the car's steering lock and do this in the Logitech profiler as well.
doesn't the "overall effects strength" need to be set above 100% to 101% - 105%, not sure if this is still the case. If it isn't then someone needs to edit the wiki
The new driver for the G25 is linear at 100% now, it was the first driver which had this problem...
As for the G27 with actual driver, after lots of testing, linearity is achieved at 105% and make sure to remove dead zone in LFS/option/controller/axis....and avoid using wheel turn compensation...
Always download last driver version on Logitech site, the one on CD is always older...