The wheelbase of any vehicle is the measurement from the center of the front wheel to the center of the rear wheel. In an effort to increase the wheelbase and subsequently improve ride characteristics, some vehicle manufactures have designed chassis that place the wheels closer to the ends of the vehicle. It is commonly agreed among designers and engineers that a longer wheelbase provides a smoother ride. On vehicles with a short wheelbase such as a Jeep CJ5, the ride is rough, as the short chassis is unable to traverse bumpy terrain one axle at a time. On short wheelbase vehicles, both axles encounter a rough spot in the road at nearly the same time, causing a harsh ride.
Luxury vehicles such as limousines utilize an extra-long wheelbase in part to offer a smoother and softer ride than can be obtained with a shorter vehicle. The longer vehicle is able to counter a rough spot on the road by floating over the bump. The added distance from axle to axle allows the chassis to dampen the rough road with one set of shocks completely prior to the other axle encountering the bump. The result is a nearly bump-free ride for the passengers of the longer wheelbase vehicle.
Other aspects of a vehicle that are directly influenced by the vehicle's wheelbase are the steering, cornering and the vehicle's ability to negotiate driveway and parking lot entrances. The reaction time for an extremely long vehicle to respond to steering input is slow. When the driver turns the steering wheel, it takes much longer for the rear of the vehicle to begin to turn than a shorter wheelbase vehicle. When the driver of a long vehicle turns the vehicle onto a road that is a 90-degree turn, he must drive past the turn prior to beginning the turn in order to allow the rear of the vehicle to negotiate the turn without driving up and over the curb.
If the driver were to begin turning onto the new street as soon as the front of the vehicle was in line with the corner, the middle of the vehicle could actually strike a sign pole positioned on the corner. By driving past the turn, the driver allows the rear of the vehicle to come into the corner and better follow the front of the vehicle through the turn. This is the same way that a semi-tractor and trailer rig negotiates a turn.
