A bad wheel alignment implies that angles of the wheels are not set correctly. This makes the engine to work harder to overcome the resistance at the wheels.
A bad wheel alignment causes a car not to track straight and it has other detrimental effects. It is caused by potholes, bumps, worn suspension and steering components and other kinds of impact on the wheels.
Cars that are equipped with air suspension have very comfortable rides but this technology has some common failure areas like the balloon, the ride height sensors, air compressor, damper and O-rings.