Proper alignment allows effortless control of the automobile. As such, improper alignment detracts from this in any way you can imagine.
Driving back from the airport this weekend we drove a rented Suzuki Vitara V6 SUV(100mi drive). When we dropped it back this morning I drove the wife's ML320. Its possible with poor alignment to make a ML320 as unstable at 70 as the Vitara.
Drifts, dives, pulls, lack of steering return, oversteer, understeer, crabbing and maybe most important TIRE WEAR.
There are specific recommended settings for your car, as all cars, but as an alignment tech I am most interested in the difference side to side in caster and camber angles. Your car should have around 9 degrees Caster and negative 0.2 degree Camber (these are from memory and are used for illustration)on the front. The rear wheel Camber is dependant on vehicle height and I would like it around 0.5 negative. With hydraulic leveling the car should be level and Camber similar side to side in the rear; that is most important.
I always drive the car for specific drivabilty before measuring. My final alignment specs are based on a combination of how the car drives (with its tires the way they will be left), how it measures, how much I can compensate without creating other conditions, and previous wear history of the tires. Basically on a neutral car I will set the caster 0.25 to 0.5 deg more positive on the right side and the Camber 0.25 to 0.5 deg more positive on the left. This tends to overcome the general tendency to drift to the right.
Bosch Master, ASE Master, L1
33 years MB technician