Different people have different opinions about vehicles. The views depend on the time and experience with different cars. There has been a continuous evolution of vehicles from the earlier horse ridden carts to the current smart and automated vehicles. Thanks to the ever advancing technology that has marked significant moments to innovators and the engineers. The evolution began with the 1908- Model T that was released by Ford Motors. In general, a car is any wheeled vehicle carrying its motor and has the capability to transport people. However, when selecting the type of vehicle to use, there are various factors that one should consider. Such factors include the road, mileage consumption, and the efficiency.
Off-road vehicles are any vehicles that can drive on the gravel surface. They have various characteristics such as large tires, flexible suspensions, and open trends to prevent them from skidding. They are more versatile and have a wide variety of use. Some off-road vehicles are designed for an off-highway and, therefore; do not meet the safety standards to be used on highways. Examples of off road vehicles include the Golf carts, snow vehicles, truck stars and all-terrain vehicles.Worm (2010) suggested some attributes possessed by all off-road vehicles. The ground clearance provides plenty of space to assist in traversing harsh terrains. Otherwise, one will have a challenge climbing the rocks and on stumps damaging the underbody of the vehicle. The underside should also be protected using the skid plates. The rock sliders protect the gas tank and the rocker panels from breaking the fire extinguisher. It is also essential to consider the approach, departure, and the differential angle.
The approach angle is an indication of the steepest hill that the vehicle can climb without damaging the front bumpers. The break over angle determines the steepest crest that can be traversed without high centering. The departure angle is an indicator of the steepest grade that a vehicle can descend without slamming the rear bumper. An off-road vehicle should have short overhangs and a large ground clearance. This helps one to descend and ascend easily.
Holm (1975, p.5) found that off-road vehicles should also have a good wheel articulation. The stability of the vehicle is crucial. A solid axle is more preferable to independent suspensions. It allows more wheel articulation. In a sandy place, however, independent suspensions are better as they provide a smoother ride with lesser unsprang mass. It is important to ensure that the off-road vehicle has a good engine to provide a low-end torque. The most recommendable engine is the 4 liter. The low-end torque allows one to maintain a momentum over obstacles without compressing the engine.
The off-road traction prediction for wheeled vehicles (1973) explains that, with the open differentials, the wheel with least traction is supplied with most power. Off-road vehicles require the wheel with the most traction to get the most power. Therefore, it is important to ensure that the two wheels are always locked on an axle together. Hence, the wheels spin at the same rate and obtain the same amount of torque. Locking may be achieved by use of pneumatic lockers called air lockers and solenoid based lockers called electronic lockers (Gunn 2004).
Proper precautions should be taken to prevent hydro locking the engine. Maintaining high mounted air intake is crucial to prevent sucking water into the engine. Robustness is crucial in off-road vehicles. Haung (2009) suggests solid axle as more robust compared to the independent suspension that has CV joints. The vehicle should also withstand high-stress encountered on off roads. They should enhance visibility to ensure safety. They should be light and small to be able to the nimble off road. It is crucial to have two points in case the vehicle gets stuck. A nylon rope instead of a chain is the most preferable. The body is on top of the frame thus ensuring that the stresses are taken by the frame preventing wearing out of the body.
Despite the efficiency of these vehicles, their effectiveness will depend on the suitability of them to different environmental conditions. Some are best suited for areas with snow while others do better in sandy places. The 4x4 vehicle does not stop any faster neither does it control any slower. It has an advantage of the capability for one to drive at the speed they wish. The 4x4 has a lower center of gravity; hence, they do roll over easily as the 2x4. The 4x4 are brushless which makes them suitable for sandy areas. A 2x4 is brushed XL5. The use 4x4 is essential in case of sticking. It provides more traction and minimal material displacement making it easier to get out. While driving on sand, it is essential for one to keep in mind the need to conserve the momentum. Carroll (1996) proposed the first precaution while planning a sand drive using 4x4 as lowering the tire pressure. Increasing the surface area of the footprint, enhances better floatation and, therefore, gives more traction. Floatation also reduces the amount of strain on the vehicle. The factors to consider when determining the tire pressure are the type of car, the type of tires, and the terrains. It is advisable to track the tire tracks of the vehicle in front. Braking the vehicle suddenly accumulates mound on all the wheels leading to a stop. Avoiding rapid changes in speed wound facilitate a smooth drive.
A smooth take off is important and changing of gears should be fair with high revs. The 4x4 vehicle requires large amounts of engine power to start the vehicle on the sand. Wide turns reduce the possibilities of blogging. When stopping on the sand, one depresses the clutch and allows the vehicle to coast to stop. One should always drive straight up and down the dunes. When recovering a vehicle after being bogged, one should never floor the accelerator. Since maintaining the momentum is the most critical, a 4x4 selects a low range to get adequate gearing and more engine revolutions.
Brojo (2010) describes it important to have a companion ready for an emergency in a 4x2 vehicle. He said that most of these vehicles did not have the recovery hooks. Therefore, it is essential to fit them before the drive starts. As opposed to the 4x4 vehicles where one has to deflate all the wheels, only the rear wheels are deflated for 4x2 vehicles. Adding an extra weight on the back of a 4x2 vehicle prevents spinning of wheels making it possible to climb hills just as a 4x4 vehicle. However, due to lack of low-range gear in 4x2, they cannot decline a step hill as the 4x4. Otherwise, the vehicle may skid due to locking of the front wheels.
In conclusion, it is advised that one avoids putting the left foot on the clutch pedal after the 2x4 vehicle starts to move. Otherwise, one might depress the clutch when the vehicle halts on a slope making it roll. Russek (1983) suggests that it is necessary for one to use the first gear to turn the ignition key until the vehicle starts again if the vehicle comes suddenly to a stop. 2x4 have low performance in the sand. The rear wheels of 2x4 vehicles tend to dig holes damaging the tracks. Windshield damage and driving safety (1984) found that the absence of low range leads to damaging of the vehicle as some obstacles have to traverse at a higher speed. To be safe, it is critical to determining the most appropriate route or otherwise use the vehicle to explore the back road scenery.
Bibliography
Brojo, P. (2010). Austin 10HP light utility. Prague: Capricorn Publications.
Carroll, J. (1996). 4x4 vehicles. London: Grange Books.
Gunn, R. (2004). Trucks & off-road vehicles. St. Paul, Minn.: Motorbooks International.
Worms, P. (2010). Off-road vehicles. London: Franklin Watts.
Crolla, D. (1981). Off-Road Vehicle Dynamics. Vehicle System Dynamics, 10(4-5), pp.253-266.
HUANG, S. (2009). General Torsional Stiffness Matching of Off-road Vehicle. Chinese Journal of Mechanical Engineering, 22(03), p.331.
Windshield damage and driving safety. (1984). Journal of Safety Research, 15(1), p.45.
Russek, P. (1983). Subaru 1600 and 1800 c.c. 2WD & 4WD vehicles. Marlow, Bucks.: Peter Russek.
Holm, I. (1970). Articulated, wheeled off-the-road vehicles. Journal of Terramechanics, 7(1), p.5.
Off-road traction prediction for wheeled vehicles. (1973). Journal of Terramechanics, 10(2), p.5.
