Top Tips For Off-Road Driving

The science of terramechanics is all very well (see last week’s post), but when you’re actually behind the wheel of a 4×4 and looking at a rugged bit of off-road track, you aren’t going to get out your calculator… and you probably don’t know all the specs and stats of the soil you’re about to drive over anyway. If you’re in this situation, what you need is some practical information. To help you with this, I’ve talked to one of the best off-road drivers that I know and have got his top tips for off-road driving.

Number 1: If In Doubt, Don’t

Sure, you want to get a thrill from taking your bush-basher off to bash some bush, but every vehicle has its limits. If the terrain looks a bit too gnarly and you’re not sure if your vehicle can handle it, then don’t risk it. It’s no fun getting stuck in the middle of nowhere, trying to use your muscles to free something that weighs at least a ton or more. It’s particularly not fun if you’ve killed your engine by getting water into where it shouldn’t be. Know your limits when it comes to approach angles, descent angles, ground clearance and water depth.

Number 2: Have Some Backup

If you’re heading out into the back of beyond, it’s a good idea to have a friend along, or at least let people know where you’re heading and roughly when you’re likely to be back – and preferably both. If you have another person along in another 4×4, then there’s another vehicle with lots of traction that can pull you out or off or up. Letting people know your plans is also helpful if something dire happens, as they can send out a search party. Locator beacons may be a step too far for some people, but at least make sure that your phone is fully charged (you may be lucky enough to get coverage).

Number 3: Control Your Speed Up And Down Hills

Heading up or down a steep and slippery incline requires some decent skill at controlling your speed.  Descending requires pointing straight down the hill and a gear high enough to utilise the traction of your 4WD system.  Too low a gear and you’ll quickly skate down the slope out of control.  Braking while descending a steep, slippery surface will also cause the wheels to lock, followed by a very quick and bumpy ride to the bottom of the hill – if you haven’t turned A over T in the meantime.  Ascending a steep and slippery slope requires strong acceleration straight up the hill the right gear to give you good momentum.  If you can’t make it up, flick the gears into reverse and back straight back down the line you came up at a speed that won’t cause your vehicle to outrun the wheels, turning so that you get into a slide for a quick descent in record time. Unable to remember all that? Get an experienced driver to act as your offroad driving instructor the first two or three times… or five.

Number 4: When Approaching A Body Of Water, Make Sure You Keep Your Air Intake Out Of It

Can you breathe underwater? No – didn’t think so. You need oxygen to function. So does your engine (oxygen’s like that). If the water’s so deep it gets into your air intake, it will go into your engine and cause all sorts of hassles, which start with messing with the ratio of oxygen to fuel, and then continue from there. The water will make the parts seize up and your engine will die.

Most serious 4x4s have their air intakes in sensible places but it’s a good idea to know where it is exactly and avoid going through anything deeper than that – or even anything almost as deep as that, as waves caused by your wake and by the motion of going through the water can splash up. Test the water with a stick or by walking ahead and checking before you plough ahead (and, depending on where you are in Australia, keep an eye out for crocs).

Snorkels can be fitted to a 4×4. These things, which resemble an elephant’s trunk, put the opening of the air intake a lot higher – above the top of the vehicle itself in some cases. If you want to do a lot of river crossings, then one of these can be worth investing in.

Number 5: When Driving On Sand, Deflate Your Tyres

Let the air out of your tyres as this gives you more traction over sand (terramechanics in action again). This will increase the amount of surface area and spread the applied force and torque (and all the other factors) across it, meaning that your tyres will bite into the sand rather than digging a hole in it.

Number 6: Ensure that the 4×4 Function Is Engaged and Properly Locked In Before Tackling A Gnarly Patch

If your vehicle is a part-time 4×4, then don’t head into the rough stuff, put on the AWD function before you get started, not just before (or just after) you get stuck.

Number 7: Have The Right Tyres

We’re back to the terramechanics, but in this case, someone has already got out the calculator, namely the designer of the tyres. Serious off-roading requires the right tyre design with plenty of good tread. Slicks are no good for you here, and even some road tyres can’t cut the mustard. Naturally, you need to make sure that the tyres are inflated to the right pressure (which will vary) and that they’re in good condition.  Mudgrip tyres are great for (you guessed it) mud!

Number 8: Pack Your Survival Kit

If you’re heading out into the wilderness in your 4×4, it’s time to release your inner Bear Grylls and be prepared for emergency situations – for you and your vehicle.

Your personal survival kit should include food and water (more than you think you will need for a day trip, just in case), clothing for all weather types, an emergency blanket and a sturdy pair of footwear (sports shoes are fine for driving in but are hopeless if you have to get out and walk through bush – swap shoes before you drive if you have to). You should also have a good first aid kit. Check out some more ideas for what should be in a survival kit from a good book or website (condoms for improvised water bottles, fish hooks and water purification tablets spring to mind).

Your vehicle’s survival kit should include a shovel for moving boulders, levelling out ruts and similar jobs. Tow ropes are also a must in case your friend needs to pull you out of somewhere. A chainsaw will often come in handy. Ensure that your spare tyre is where it should be, and pack a pump for the tyres that can be powered by your vehicle’s power outlet (formerly known as the cigarette lighter; my age is showing).

Number 9: Invest In A Winch

There are plenty of types of winch. Some are directly mounted on the vehicle so you can just hook the chain or rope securely round a solid anchor point from the winch on the vehicle. Others are manual winches, where you can anchor the winch from an anchor point beyond the vehicle and use the winch to pull the vehicle out of the stuck position.

Number 10: Make Sure You’ve Got Enough Fuel!

Terramechanics: The Science Of Off-Roading

A lot of us have purchased, or have considered purchasing, a 4×4 vehicle. This could be because we like the benefits of extra safety or the visibility of the higher body. Or it could be that we want to go off-road in the vehicle and do a spot of exploring. However, when we get behind the wheel of one of these vehicles and head for the nearest dirt road or river, we don’t often stop to think about all the science behind what we’re about to do. The most we might think about are things like the power and torque needed – and possibly the basic physics involved in getting over or around a gnarly bit of terrain.

However, there’s a whole branch of science related to off-road driving, known as terramechanics. In fact, there’s a specialised scientific journal on the topic. Terramechanics has been a scientific topic since the 1950s, and the concept was introduced by a Polish-born engineer by the name of Dr Bekker, who was one of the key developers of the lunar rover vehicle used on the moon. However, much of Dr Bekker’s work was more down to earth – literally.

Terramechanics, in a nutshell, is the science of how a vehicle operates off-road on rough, uneven and soft terrain. It mostly considers the interaction between the wheels and the ground, although the science also acknowledges that things like the length of the wheelbase, the torque and the ground clearance are all very important factors. However, it’s what happens where the rubber meets the (off) road that gets certain people in white coats (probably dirty white coats) very excited.

Now, if you get right into terramechanics, the maths gets pretty complicated. If you’re like me, you probably left quadratic equations behind once you left high school. However, engineers and designers in the field of terramechanics use them all the time. I won’t get into the heavy-duty maths, but here, we’ll have a little look at some of the things that get thought of when the designers are coming up not just with new 4×4 models but also with the tyres that go on them.

Vehicle-related factors

Load: the weight of the vehicle plus what’s in it – probably you, a friend, the dog and something to eat.

Contact area: Exactly how much of the tyre is touching the ground. This is affected by the design of the tyre, the width of the tyre, how much air you put in the tyre and the condition of the tread.

Rolling resistance: Also known as friction.

Torque: You knew this one was going to be important, didn’t you? That’s why the torque – the measure of rotational acceleration (rather than linear acceleration) is always given in the specs of any vehicle.

Wheel width: Put simply, more contact area means more grip.

Wheel radius: There’s a reason why 4x4s have bigger tyres, and it’s not just for better ground clearance.

Terrain-related factors

Designers have to consider these factors when they design tyres and the vehicles. As anybody who’s done any off-roading will know, not all types of terrain are created equal, and the techniques and tyres that work well with, say, snow won’t work with sand.

In fact, a lot of what goes on in terramechanics considers the properties of the soil or the other terrain (snow and sand). You might think of soil as just mud or good plain dirt, but it’s pretty complicated stuff. It’s a combination of solids (the actual particles of soil), liquids (water) and gases (air), and it’s constantly changing even in a single place, to say nothing of how soil varies from place to place. I won’t bore you with all the different factors, what they mean and how they affect each other, but some of the most important ones that researchers have to specify when they run tests of new tyre designs or even whole cars are the following:

Moisture content: How much water is in the soil at any point. This affects the shear strength of the soil, which is very important in a lot of the formulae used in terramechanics to work out whether a wheel will lose traction or not. The shear strength of anything is its ability to stand up to a force that will make it slip sideways.

Porosity: How much air is inside the soil – these pores are where the water goes when you water the garden.

Particle size and shape: How big the minute particles of soil are and what shape they are has a big influence on how the dirt sticks together, holds moisture and compacts under pressure. Most of us have known since childhood that sand and clay are very different, and this difference is mostly down to particle size and shape.

Specific gravity: How dense a substance is. Yes, this is related to the specific gravity known to home brewing enthusiasts.

After considering these basic factors, things start involving complicated equations that make my head ache.

You know, I’m kind of glad that when I go off-road driving, I don’t have to keep all these factors and the science in my head – otherwise, I’d overthink everything all the time and wouldn’t enjoy the experience. An experienced off-road driver will be able to do by feel and “instinct” (i.e. right-brain thinking) what the terramechanics expert would have to calculate. All the same, I’m glad that there are people working hard to make sure that our vehicles and the tyres on them are the safest and best they can be.

New Cars, New Year.

Happy New Year to you all!  2023 sees some brand new cars coming into view, and we’re set to observe a considerable increase in the number of EVs sold on our shores.  Here’s a brief look at some of the exciting cars and SUVs you can get your hands on in the near future!

Alfa Romeo Tonale

Here’s the first of the Alfas that take the special brand into EV mode.  The Alfa Romeo Tonale Hybrid kicks it off with its hybrid engine offering the new 48-volt hybrid propulsion system.  You’d expect an Alfa to be sporty, and the nicely designed compact SUV delivers on this front.  Comfortable interiors and decent technology make this a good way of upgrading into 2023.

BMW iX1

The smallest X model from BMW comes in as the X1, and the iX1 is the EV model with a battery range up over 400 km.  Nicely laid out interiors, an athletic driving style (typical Beemer), and a good dollop of performance make this a great new compact SUV.

BYD Atto 3

The BYD Atto 3 is a new kid on the block for Australia.  Being an electric medium-sized SUV with a decent range makes this an efficient EV for the new year.  The Atto 3 also offers a comfy interior and plenty of the latest technology and safety features.

CUPRA Born

CUPRA cars are exciting.  They have plenty of performance and are generally a well-priced product with high-end features.  This new model called the CUPRA Born is an EV with a handsome range of beyond 500 km.  The CUPRA Born is an exciting car to look at, and it comes with advanced technology and great connectivity.

Ford E-Transit

Ford’s lovable Transit has a new ticker with the latest vans now offering electric power.  This is a brand new, full-size, pure-electric E-Transit that features a 68 kWh battery and a driving range of up to 317 km.  Ford say that it is possible to fast-charge the E-Transit from 15% to 80% in a bit over 30 minutes.

GWM Tank 300

One of the best vehicles to come out of 2023 will be the impressive looking GWM Tank 300.  Doesn’t it make a statement!  The Tank is powered by a 2.0-litre petrol-electric hybrid system, and the internal-combustion engine offers a juicy 180 kW.  Nappa leather, all the tech, and very handy off-road makes this a hugely appealing.

Lexus RX

Toyota has their luxury Lexus brand offering their latest RX.  If you’re wanting a new hybrid, these are some of the best ones out there.  Toyota make a great hybrid powertrain with smooth performance and impressive efficiency.  The RX interior sees an updated luxury interior design with ever-impressive build quality.  The RX is roomy too and very comfortable.

Maserati Grecale

Maserati is becoming ever more affordable.  That’s a great thing because they make great cars.  The new Maserati Grecale is a front-engine, medium-sized luxury SUV that comes with the promise of plenty of performance.  Three engines are available: two 2.0-litre petrol motors and a 3.0-litre V6 petrol.  Generous on the equipment levels, the Grecale will be rewarding to drive.

MG4

MG offers the new MG4 hatchback this year.  It is an affordable electric hatchback that has been packed full of innovation, style, technology, and an impressive 440 km driving range.

Nissan X-Trail E-Power Hybrid

Nice to look at, and equally at home off-road as it is on, the Nissan X-Trail E-Power Hybrid SUV is very comfortable and very well-equipped.  Rear cargo capacity in the 5 seat version of this awesome SUV is 575 litres (super handy for a family).  A 7-seat option is also available.  The entry point model is a mild hybrid version and uses a 1.5-litre petrol most of the time.  The other powerplant uses the same 1.5-liter ICE, but it doesn’t connect to the wheels directly.  Instead, it becomes the electrical generator of the system that works in unison with a small battery operating as a buffer.  The wheels are fed power via electric motors.

Renault Kangoo

Renault’s new Kangoo definitely can do, especially with its brand new E-Tech EV versions becoming available for the Australian market.  This will be Australia’s cheapest electric van.  The E-Tech has a 90 kW/245 Nm electric motor that drives the front wheels via a single-speed transmission.  You should easily run about town for well over 250 km before needing to recharge.

Keep your eyes open for these new models travelling our roads and on showroom floors across Australia.  Also keep your ears open via Private Fleet, where we’ll keep you up to date with what other new models are coming our way shortly.  All the best for 2023!

Are You Feeling Sleepy?

Anybody else feeling a bit tired at this time of year? What with all the build-up to Christmas, the Big Day itself, the weirdness of the in-between days at the end of December and the fun of staying up all night to see in the new year, it would be unsurprising if you weren’t a bit tired. This is especially the case if you’re one of the many who has to keep working during this time of year (because cars still need fuel, fruit needs to be harvested, cows need to be milked and people need to eat). Add in the fact that this is when quite a lot of people like to drive longer distances to visit relatives or to go somewhere on holiday, and you get a much higher risk of people driving fatigued.

Fatigue is more than just ordinary tiredness. According to the dictionary, fatigue is a state of complete mental and physical exhaustion, of being completely and utterly worn out or, as C.S. Lewis would put it “dog-tired, cab-horse tired, tired like a child in a factory”. You could refer to it as being overtired.

Why Fatigue Matters

Fatigue matters because it affects your driving. It makes you less alert and less aware of your surroundings, and it slows your reaction time. It also affects your thinking powers so that you make crappy decisions. In short, driving fatigued is at least as bad as driving drunk. In fact, the two are pretty similar. Both slow your reaction times and affect your ability to make decisions. However, people who drive drunk are likely to make impulsive, reckless decisions, whereas those who drive when exhausted are likely to be less alert, less aware of hazards and slow to make a judgement call. In fact, driving after having been awake for 20 hours is the equivalent to driving at the legal alcohol limit.

Fatigue also carries the risk of nodding off at the wheel. You can see why. It’s dark outside (signalling to your body that it’s night time and therefore bedtime), the white lines on the road flick by monotonously (which has a hypnotic effect), the car seat is beautifully padded and supportive, and the interior of the car is warm… Before you know it, you can feel your eyelids drooping and your head nodding. Not good. Even if you nod off for a second, that can be one second too many if your car swerves.

Unfortunately, although you can estimate breath or blood alcohol levels, you can’t measure fatigue. You can’t even pin it down purely to the number of hours you’ve slept for the way you can pin down the amount of alcohol you’ve had using the number of standard drinks. Although lack of sleep is one component of fatigue, it’s not the only factor. Someone who had had one bad night of sleep can be less fatigued when driving than someone who’s had a week or more of wakefulness and insomnia, even though the first person has had fewer hours of sleep last night. A lot of things influence your level of fatigue other than how much sleep you’ve had – there’s how stressed or emotionally drained you’re feeling, any mental fatigue you’re going through (hard day at work, anyone?), what exercise you’ve done and what you’ve been eating.

One contributor to fatigue, both mental and physical, is doing the same thing for hours and keeping alert and focused on one thing for hours. This is exactly what happens when you’re driving, especially if you have to focus intently the entire time (e.g., in very busy traffic). This makes long-haul driving especially risky.

Then there’s the little matter of your body clock. It’s natural for the hormones in your body to fluctuate during the day, although this can be influenced by what you’ve been eating and/or drinking (looking at you, caffeine). This means that you can be feeling fine in the morning even though you’ve only had five hours of sleep the night before, then feel sleeeeeeepyyyyy come midday. In fact, it’s natural for people to feel a bit lethargic in the middle of the day after lunch, and it’s not just because of the heat. Your body clock can be messed with by a number of things, including shift work, the changeover to and from daylight savings, having a new baby in the house… and even the very common habit of staying up late and sleeping in on weekends.

How Can You Avoid Driving While Fatigued?

The main cause of fatigue is poor sleep, so the obvious answer to how you can avoid driving while fatigued is to ensure that you get a good night’s sleep on a regular basis. The odd broken night, late night or very early morning probably won’t hurt you or your driving, but if it happens too often, you could be putting yourself and your passengers in danger.

This is primarily a driving blog rather than a health blog, so I can’t go into too much detail about how to get a good night’s sleep, but here are some ideas:

• Have a regular bedtime routine, which helps your body wind down and get ready to sleep.
• Wake up at the same time every day (yes, even on weekends!).
• Avoid blue light (e.g., screens without a filter) last thing at night.
• Keep your bedroom dark and minimize the number of devices you keep in there.
• Watch your caffeine intake. A good rule of thumb is to have your last cup of coffee at 4 pm, and switch to other drinks after that.
• Avoid thinking about, reading about or watching anything likely to make you stress, angst or worry – including the fact that you can’t sleep if you’re having trouble dropping off.

Other ways that you can help avoid fatigue when you’re driving are the following:

• Know yourself. If you’re a night owl, avoid driving in the early morning when you’re not fully awake. If you’re an early bird, then avoid driving later at night.
• Be aware of your natural ebb and flow of sleep-related hormones. If you know that you’re tired, it may be best to avoid driving during the early afternoon slump. This is a good excuse to get out and go for a stroll (which will ease some of the mental fatigue and give you a good oxygen burst) or to take a siesta.
• Having extra coffee – although this only works in the short-term and will wear off and leave you even more fatigued, so use this one with caution.
• Opening the window for fresh air and switching on some pumping music. Again, these are only short-term fixes to wake the brain up by increasing oxygen intake and getting some natural stimulation (in the form of music). However, these also wear off fairly quickly.
• Share the driving. If you know that you have to put in a long-haul drive, then arrange for the passenger to take a sleep first as you go (eye masks and a nice pillow help here), then swap.
• PULL OVER AND TAKE A NAP. It won’t kill you if you pull over somewhere safe, turn off the engine put the seat back and have a short nap (about 10 minutes or so). However, falling asleep at the wheel may kill you. If you’ve got kids in the car, then wait until they’re asleep before you do this if you’re alone. If there’s another adult in the car, then the other adult can keep an eye on the kids while they whizz around in a playground and you sleep. But get that nap. It’s better to arrive 10 minutes late than to not arrive at all.