What makes a good off-road vehicle?
Top Five Characteristics of a Good Off-Road Vehicle
Off-roading is a thrilling experience that challenges both the vehicle and driver. However, to tackle rough terrains successfully, your vehicle must possess certain characteristics that enhance its performance and ensure safety. Here, we delve into the top five characteristics that define a good off-road vehicle: Torque, Tyres, Ground Clearance, Approach, Departure, and Ramp-over Angles, and Rated Recovery Points.
Torque
Torque is the backbone of off-road performance. Unlike horsepower, which measures a vehicle's speed, torque is about the twisting force that allows your vehicle to move from a standstill, especially on steep inclines or rocky terrains. A UTE with torque over 350 Nm is adequate to take on the terrain of Australia without any dramas. However, the importance of low-end torque cannot be overstated—it provides the control needed when navigating challenging landscapes. Vehicles with high low-end torque can maintain steady momentum over obstacles without requiring excessive throttle, which can lead to loss of traction.
An ideal off-road vehicle combines ultra-low-range gearing with substantial torque. This pairing ensures that the vehicle can crawl over rocks, wade through mud, or climb steep hills without stalling. While modern off-road vehicles often come equipped with high-tech aids like traction control and hill descent control, these features are secondary to the fundamental importance of torque in off-road situations.
Tyres
Tyres are the only part of your vehicle that makes direct contact with the terrain, making them critical to off-road performance. The type of tyre you choose can make a significant difference in how your vehicle handles various surfaces. Off-road enthusiasts typically consider four main types of tyres: Highway Terrain (HT), All-Terrain (AT), Mud Terrain (MT), and Light Truck (LT) tyres.
- HT Tyres are designed for road use and offer limited off-road capability.
- AT Tyres are versatile, providing a balance between on-road comfort and off-road performance.
- MT Tyres are designed for extreme off-road conditions, with aggressive tread patterns that provide maximum grip on loose or muddy surfaces.
- LT Tyres are similar to AT tyres but are built for heavier loads and offer greater durability in rugged conditions.
For most off-roaders, investing in top-quality AT or LT tyres is highly recommended. These tyres offer the best compromise between daily driving and off-road capability. While they may be more expensive, with costs ranging from $200 to $500 per tyre, the investment pays off in increased durability, safety, and performance.
Ground clearance
The higher the car is above the earth below the less chance it has of scraping or getting stuck. Most four-wheel drives have more than 200mm of ground clearance, with some approaching 300mm. That compares with around 130-160mm for passenger cars and up to 200mm for many road-biased SUVs. Ground clearance has a big bearing on how far you can go without risking impacting the undercarriage.
Approach, Departure, and Ramp-over Angles
These angles are critical for determining a vehicle's ability to tackle steep slopes and obstacles without hitting the ground.
- Approach Angle: The maximum angle your vehicle can climb without the front bumper touching the ground.
- Departure Angle: The maximum angle your vehicle can descend without the rear bumper hitting the ground.
- Ramp-over Angle: The maximum angle your vehicle can pass over an obstacle without the underside touching.
Vehicles like the Land Rover Defender are designed with superior angles, featuring an approach angle of 38 degrees, a departure angle of 40 degrees, and a ramp-over angle of 28 degrees. These angles allow the vehicle to handle steep inclines, declines, and obstacles with ease, significantly enhancing off-road performance.
Poor angles can limit your ability to navigate difficult terrain, potentially causing damage to the vehicle's body or undercarriage. Therefore, these angles should be a top consideration for anyone serious about off-roading.
Rated Recovery Points
No matter how well-equipped your vehicle is, getting bogged down in mud, sand, or snow is sometimes unavoidable in off-roading. When this happens, rated recovery points become crucial for safely towing your vehicle out of trouble. Rated recovery points are specifically designed for this purpose and are much stronger than factory tie-down points or tow balls, which can fail under the strain of recovery operations, posing significant safety risks.
Investing in properly installed rated recovery points is essential for anyone planning to take their vehicle off-road. These recovery points are typically attached to the vehicle's chassis and are built to withstand the forces involved in vehicle recovery, ensuring that the towing process is safe and effective.
Protection underneath
All cars have some sort of protection underneath, but in most instances it’s plastic that is designed mostly to smooth the airflow to improve aerodynamics and reduce fuel use. Proper off-roaders protect key components such as the engine, transmission and fuel tank with more serious metal coverings. It means they can typically deflect a scrape or hit underneath, especially if it’s at low speed (most off-roading is done at slower speeds).
People who are very serious about their four-wheel driving may fit even stronger and more serious underbody protection. But at the very least you want metal protecting the critical components.
Dual-range transfer case
Hard core off-roaders will tell you a dual-range transfer case is what defines a proper 4WD. That’s not entirely true. A dual-range transfer case provides a separate set of gear ratios that make all the gears lower. So first gear, for example, will have the engine spinning much faster at 5 or 10km/h when low range is engaged. It’s designed to help with engine braking down a hill and allow slow speed crawling. It also makes it easier to get up very steep hills that may have been impossible for the engine if relying on regular gear ratios.
While most proper off-roaders have a dual-range transfer case – either selected via a second gear lever or, in newer models, a button or dial – it’s not mandatory for good off-road performance. Most Volkswagen Amaroks, for example, don’t have a dual-range transfer case, but they’re very capable 4WDs.
Locking differentials
Traction is king in a 4WD. And while car makers are increasingly turning to electronics such as traction control to adjust which wheels the engine sends torque to, it’s not perfect. For traction control to work, for example, it first needs to detect wheelspin, which in some instances could be enough to get you bogged. That’s where locking differentials come into play.
A differential is the thing that accounts for the difference in distance travelled between left and right wheels (AWDs and some 4WDs also have a centre differential to account for the difference in distance between front and rear wheels). Without a differential the car will be harder to manoeuvre and tyre wear is increased because the left and right are spinning at the same speed. But with a locked differential – or up to three locked diffs on a 4WD – the wheels can spin at exactly the same speed.
It means all four wheels have to be spinning before the car will stop moving. The added finesse of being able to feed on power without the wheelspin required to trigger traction control makes locking diffs very effective when traction is limited.
Snorkels and more
Most proper off-roaders are rated to drive through somewhere between 500mm and 900mm of water. Cars with a higher rating typically have their air intake under the bonnet positioned so that it is less likely to suck in water (something that can kill an engine). Or they could have a snorkel, which can raise the water fording depth even higher.
Make sure you know where your car’s air intake is and what it’s depth rating is. And don’t go being optimistic; if it’s 480mm deep and your car is rated at 500mm you need to be very, very careful and ensure you enter the water at the correct speed. Water crossings can be dangerous, especially if the water is moving.
Conclusion
A good off-road vehicle is defined by its ability to navigate challenging terrains with ease and reliability. Key characteristics include robust low-end torque for controlled power delivery, high-quality all-terrain tyres for optimal traction, sufficient ground clearance to avoid obstacles, and favorable approach, departure, and ramp-over angles to tackle steep slopes. Additionally, rated recovery points ensure safe extrication when bogged down. These elements collectively equip a vehicle to handle the rigors of off-roading, making it capable, durable, and dependable in the most demanding environments.
Top Five Characteristics of a Good Off-Road Vehicle
Off-roading is a thrilling experience that challenges both the vehicle and driver. However, to tackle rough terrains successfully, your vehicle must possess certain characteristics that enhance its performance and ensure safety. Here, we delve into the top five characteristics that define a good off-road vehicle: Torque, Tyres, Ground Clearance, Approach, Departure, and Ramp-over Angles, and Rated Recovery Points.
Torque
Torque is the backbone of off-road performance. Unlike horsepower, which measures a vehicle's speed, torque is about the twisting force that allows your vehicle to move from a standstill, especially on steep inclines or rocky terrains. A UTE with torque over 350 Nm is adequate to take on the terrain of Australia without any dramas. However, the importance of low-end torque cannot be overstated—it provides the control needed when navigating challenging landscapes. Vehicles with high low-end torque can maintain steady momentum over obstacles without requiring excessive throttle, which can lead to loss of traction.
An ideal off-road vehicle combines ultra-low-range gearing with substantial torque. This pairing ensures that the vehicle can crawl over rocks, wade through mud, or climb steep hills without stalling. While modern off-road vehicles often come equipped with high-tech aids like traction control and hill descent control, these features are secondary to the fundamental importance of torque in off-road situations.
Tyres
Tyres are the only part of your vehicle that makes direct contact with the terrain, making them critical to off-road performance. The type of tyre you choose can make a significant difference in how your vehicle handles various surfaces. Off-road enthusiasts typically consider four main types of tyres: Highway Terrain (HT), All-Terrain (AT), Mud Terrain (MT), and Light Truck (LT) tyres.
- HT Tyres are designed for road use and offer limited off-road capability.
- AT Tyres are versatile, providing a balance between on-road comfort and off-road performance.
- MT Tyres are designed for extreme off-road conditions, with aggressive tread patterns that provide maximum grip on loose or muddy surfaces.
- LT Tyres are similar to AT tyres but are built for heavier loads and offer greater durability in rugged conditions.
For most off-roaders, investing in top-quality AT or LT tyres is highly recommended. These tyres offer the best compromise between daily driving and off-road capability. While they may be more expensive, with costs ranging from $200 to $500 per tyre, the investment pays off in increased durability, safety, and performance.
Ground clearance
The higher the car is above the earth below the less chance it has of scraping or getting stuck. Most four-wheel drives have more than 200mm of ground clearance, with some approaching 300mm. That compares with around 130-160mm for passenger cars and up to 200mm for many road-biased SUVs. Ground clearance has a big bearing on how far you can go without risking impacting the undercarriage.
Approach, Departure, and Ramp-over Angles
These angles are critical for determining a vehicle's ability to tackle steep slopes and obstacles without hitting the ground.
- Approach Angle: The maximum angle your vehicle can climb without the front bumper touching the ground.
- Departure Angle: The maximum angle your vehicle can descend without the rear bumper hitting the ground.
- Ramp-over Angle: The maximum angle your vehicle can pass over an obstacle without the underside touching.
Vehicles like the Land Rover Defender are designed with superior angles, featuring an approach angle of 38 degrees, a departure angle of 40 degrees, and a ramp-over angle of 28 degrees. These angles allow the vehicle to handle steep inclines, declines, and obstacles with ease, significantly enhancing off-road performance.
Poor angles can limit your ability to navigate difficult terrain, potentially causing damage to the vehicle's body or undercarriage. Therefore, these angles should be a top consideration for anyone serious about off-roading.
Rated Recovery Points
No matter how well-equipped your vehicle is, getting bogged down in mud, sand, or snow is sometimes unavoidable in off-roading. When this happens, rated recovery points become crucial for safely towing your vehicle out of trouble. Rated recovery points are specifically designed for this purpose and are much stronger than factory tie-down points or tow balls, which can fail under the strain of recovery operations, posing significant safety risks.
Investing in properly installed rated recovery points is essential for anyone planning to take their vehicle off-road. These recovery points are typically attached to the vehicle's chassis and are built to withstand the forces involved in vehicle recovery, ensuring that the towing process is safe and effective.
Protection underneath
All cars have some sort of protection underneath, but in most instances it’s plastic that is designed mostly to smooth the airflow to improve aerodynamics and reduce fuel use. Proper off-roaders protect key components such as the engine, transmission and fuel tank with more serious metal coverings. It means they can typically deflect a scrape or hit underneath, especially if it’s at low speed (most off-roading is done at slower speeds).
People who are very serious about their four-wheel driving may fit even stronger and more serious underbody protection. But at the very least you want metal protecting the critical components.
Dual-range transfer case
Hard core off-roaders will tell you a dual-range transfer case is what defines a proper 4WD. That’s not entirely true. A dual-range transfer case provides a separate set of gear ratios that make all the gears lower. So first gear, for example, will have the engine spinning much faster at 5 or 10km/h when low range is engaged. It’s designed to help with engine braking down a hill and allow slow speed crawling. It also makes it easier to get up very steep hills that may have been impossible for the engine if relying on regular gear ratios.
While most proper off-roaders have a dual-range transfer case – either selected via a second gear lever or, in newer models, a button or dial – it’s not mandatory for good off-road performance. Most Volkswagen Amaroks, for example, don’t have a dual-range transfer case, but they’re very capable 4WDs.
Locking differentials
Traction is king in a 4WD. And while car makers are increasingly turning to electronics such as traction control to adjust which wheels the engine sends torque to, it’s not perfect. For traction control to work, for example, it first needs to detect wheelspin, which in some instances could be enough to get you bogged. That’s where locking differentials come into play.
A differential is the thing that accounts for the difference in distance travelled between left and right wheels (AWDs and some 4WDs also have a centre differential to account for the difference in distance between front and rear wheels). Without a differential the car will be harder to manoeuvre and tyre wear is increased because the left and right are spinning at the same speed. But with a locked differential – or up to three locked diffs on a 4WD – the wheels can spin at exactly the same speed.
It means all four wheels have to be spinning before the car will stop moving. The added finesse of being able to feed on power without the wheelspin required to trigger traction control makes locking diffs very effective when traction is limited.
Snorkels and more
Most proper off-roaders are rated to drive through somewhere between 500mm and 900mm of water. Cars with a higher rating typically have their air intake under the bonnet positioned so that it is less likely to suck in water (something that can kill an engine). Or they could have a snorkel, which can raise the water fording depth even higher.
Make sure you know where your car’s air intake is and what it’s depth rating is. And don’t go being optimistic; if it’s 480mm deep and your car is rated at 500mm you need to be very, very careful and ensure you enter the water at the correct speed. Water crossings can be dangerous, especially if the water is moving.
Conclusion
A good off-road vehicle is defined by its ability to navigate challenging terrains with ease and reliability. Key characteristics include robust low-end torque for controlled power delivery, high-quality all-terrain tyres for optimal traction, sufficient ground clearance to avoid obstacles, and favorable approach, departure, and ramp-over angles to tackle steep slopes. Additionally, rated recovery points ensure safe extrication when bogged down. These elements collectively equip a vehicle to handle the rigors of off-roading, making it capable, durable, and dependable in the most demanding environments.
