The front and rear suspension of the GranTurismo uses air springs for a smoother, controlled ride than the 4 Series Coupe, which uses coil springs. Air springs maintain proper ride height and ride more smoothly.
The GranTurismo has a standard automatic front and rear load leveling suspension to keep ride height level with a heavy load or when towing. The GranTurismo’s height leveling suspension allows the driver to raise ride height for better off-road clearance and then lower it again for easier entering and exiting and better on-road handling. The 4 Series Coupe doesn’t offer a load leveling suspension.
For a smoother ride and more stable handling, the GranTurismo’s wheelbase is 3.1 inches longer than on the 4 Series Coupe (115.3 inches vs. 112.2 inches).
For better handling and stability, the average track (width between the wheels) on the GranTurismo is 2.5 inches wider in the front and 2.1 inches wider in the rear than the average track on the 4 Series Coupe.
The GranTurismo Trofeo handles at .97 G’s, while the M440i xDrive Coupe pulls only .91 G’s of cornering force in a Car and Driver skidpad test.
The GranTurismo Trofeo executes Motor Trend’s “Figure Eight” maneuver quicker than the M440i xDrive Coupe (24.1 seconds @ .84 average G’s vs. 24.7 seconds @ .78 average G’s).