18 Off-Road Driving Flashcards
First step in safe off-road driving:
A thorough knowledge of the vehicle
Drivers must understand the vehicles:
capabilities and (more importantly) limitations
Front Wheel Drive Advantages
- Provide better traction on slick roads - weight of engine, transmission, and mechanical components rest on front axle
- Most provide better fuel economy
Front Wheel Drive Disadvantages
- Tends. to be nose heavy
- Susceptible to Torque Steering (may pull to right or left during heavy acceleration)
Rear Wheel Drive Advantages
- Better acceleration
- Better weight distribution - improves stability and handling.
Rear Wheel Drive Disadvantages
- Poor handling on slick roads
All Wheel Drive
Designed to handle slippery conditions on a paved highway.
Four Wheel Drive
Power transfers from drive train to transfer case where power is divided front and rear axles so maximum torque is applied to all four wheels
4WD Low
- Designed to provide more torque for off-road use
- Slow speeds
- More power to go up hills and increased engine braking to descend hills
- Does not provide more traction, just torque
Crawl Ratio
Ability to travel over rough terrain in first gear at idle speed without having to depress the clutch pedal to keep the vehicle from stalling
4WD High
- Designed for slippery conditions like loose dirt, gravel, or sand
- Not designed for rough off-road conditions
Open DIfferential
Torque is split equally between wheels on the axle
Locking Differential
Wheels on the axle are locked together and will both spin at the same speed when torque is applied - regardless of traction.
Limited-Slip Differential
Combine advantages of Open and Locking - Allows tires to rotate at different speeds but also allow torque transfer between tires when needed.
Off Road Driving Considerations
- Driving Surface
- Terrain
- Vehicle