Africa Overland Contents:
Of the many crucially important factors to consider when deciding on an Africa overland expedition vehicle for an undertaking of this magnitude, personal preferences should be the very last one on the list. While fuel economy and available power is important, the overriding consideration MUST ALWAYS be reliability. It makes no difference whether you like a particular brand of vehicle or not, or if your neighbour’s cousin’s father-in law happens to have had good or bad experiences with a particular model on his farm- the reality is that there are very few repair facilities in the African hinterland, and should you choose a vehicle (perhaps inadvertently) with known reliability issues, or just because you like its looks, or if your chosen vehicle cannot be repaired in the bush, either by yourself or by your designated, and hopefully experienced mechanic, you are guaranteed to end up being in serious trouble.
Africa is notoriously unforgiving of mistakes in planning and general lack of preparedness, which makes it a particularly bad idea to base your choice of vehicle on TV advertising, or worse, claims made by uninformed salespersons, for whom the term “off-roading” probably means parking their company pick-ups on their lawns- to better show off their shining rims and usually over-sized tyres. It is not an exaggeration to say that your life could depend on the reliability of your chosen vehicle, and while this article does not have the intention, or purpose, of promoting one vehicle brand over another, there is one thing that all successful or competent Africa overland expedition vehicles have in common, and that is proven, built-in reliability.
So, apart from proven reliability, what else do you need in an Africa overland expedition vehicle? The obvious answer to this of course, is that you need as much as you can get for your money, but since you cannot always get what you want, and given the fact that there are as yet no perfect 4×4’s, the points listed below will go a long way toward ensuring you stand at least a fighting chance of completing your overland expedition successfully, so consider them carefully:
Diesel power vs. fuel economy
While petrol engines can develop just as much power as any diesel, the advantage of diesels lays in the fact that they develop their power at much lower engine speeds, which is one of the reasons why diesels are more fuel efficient than petrol engines- by several orders of magnitude. This fact alone makes diesels the better choice, since fuel supplies can be erratic in some parts of Africa, but there are other, equally compelling reasons to go for diesel engines, among which are:
Diesel engines have fewer components
Diesel engines do not have complicated ignition circuits that can get wet, and if you are lucky, just short out when they do, and work again once you have it dried out: deep-water crossings have completely immobilised petrol engines since time immemorial by causing fatal short circuits and malfunctions. A diesel engine will run as long as there is battery power available, and some will even run without any electrical power at all, provided the electrically powered fuel cut-off solenoid on the main pump is replaced by some other means of shutting the engine off.
Diesel vehicles can run on bad quality fuel
Africa is not known for the consistently high quality and purity of its fuel supplies, and provided extra filtration is provided on your vehicles, a diesel will run on almost anything, whereas petrol engines are extremely sensitive to fuel quality, so much so in fact, that much of the petrol sold in Africa can cause modern petrol engines not to run at all.
However, there is more to this issue than the fact that diesels can run on bad fuel: most modern diesels require diesel with a low sulphur content, i.e., 50 PPM, to run at peak efficiency, and although running these engines on high sulphur content diesel, i.e., 500 PPM will not necessarily ruin them, components such as catalytic converters and DPF’s (Diesel Particulate Filters), might be damaged. The primary purpose of sulphur in diesel is to act as a lubricant, but the removal of excess sulphur means that exhaust gasses are much cleaner, and by using advanced conversion technology coupled with a means to burn off the little soot that does form, manufacturers can clean diesel exhaust gas even further-, so much so in fact, that in many cases diesel exhaust is now cleaner than petrol exhaust gas.
All of this is well and good, and great for the environment, but the problem is that 50 PPM diesel is not yet widely available in Africa, so what do you do? One solution is to have both the catalytic converter and the DPF removed, which may result in a reduced warranty, as well as permanently illuminated warning lights on the dashboard. This is not the ideal solution, but it is better than having to remove a clogged-up catalytic converter in the bush, which is what will happen if you run a 50 PPM engine on 500 PPM diesel for long periods.
The other solution is to use an overland expedition vehicle is that is still capable of running on 500 PPM diesel, although these engines are becoming scarcer by the day. Nonetheless, whichever option you choose, always bear in mind that some of the diesel you buy in Africa can be a witches’ brew of paraffin, water, “performance boosters”, petrol, and who-knows-what-else, so always get your fuel from branded service stations only, where you have the best chance of getting fuel of a reasonable quality; after all, the locals have to use that fuel as well, so it can’t always be that bad.
However, never buy fuel in the bush, or in small villages that sometimes offer fuel decanted from drums- you have no way of knowing what is in it; you cannot test it, and there is a more than even chance that it might ruin your engine a hundred kilometers down the road.
Diesel Engines are easier to repair
Although modern diesel engine management systems have become more complex in recent years, they still have at least six or seven fewer sensors and sub-systems than petrol engines, which means that fault diagnosis is much easier, and nine times out of every ten, just replacing the ECU with a pre-programmed unit will get you mobile again.
While a solid front axle has definite advantages over an independent front suspension in terms of ground clearance, an independent suspension provides a much softer ride, and given the fact that an African overland expedition can be several tens of thousands of kilometers long, the comfort that an independent suspension provides becomes an important consideration. The disadvantages of an independent suspension, in that it does not alter the ground clearance between the differential and the road surface, can be largely offset by increasing the overall ground clearance somewhat by fitting an extra blade to the rear axle and using slightly longer coil springs on the front axle. However, doing this will negatively affect the rollover angle due to the altered centre of gravity, but limiting the load on the canopy, or not loading anything on the canopy largely eliminates the problem, provided the suspension is not lifted by more than 50 mm or so.
Having a lockable rear differential is an absolute requirement for off-road driving in Africa, but having a lockable front axle as well is even better, since it effectively doubles the effect of the rear diff lock. There are many places in Africa where a single diff lock may not provide sufficient traction, and having a second, lockable axle may be the only way to successfully traverse the long, muddy trenches that pass for roads in the rain forests of equatorial Africa- especially in the monsoon season.
Automatics have a definite advantage over manuals in that they take much of the grind out of driving long distances, but they have some serious drawbacks as well, not the least of which is the fact that they provide no engine braking capability.
Engine braking is an essential off-road driving asset, in the sense that it can replace conventional braking methods on loose, slippery surfaces such as sand dunes and/or descents on loose gravel. By virtue of their design, automatic transmissions do not provide the solid mechanical link between the wheels and the engine via the transmission required for efficient engine braking, which means that some obstacles could be dangerous when attempted with an automatic, even if it has a transfer case with low range.
Manual transmissions on the other hand, have the disadvantage that clutches may not survive for long at the hand of inexperienced drivers, which means that having to replace a clutch in the bush is a real possibility. On a proper 4×4 equipped with low range this is no laughing matter, even for experienced mechanics, but provided there are no inexperienced drivers on your expedition, a manual transmission is by far the better choice because of the engine braking capability it provides.
The primary function of electronic driving aids such as traction control, electronic brake distribution, ABS, autonomous braking, and others, is to assist the driver in maintaining control while driving at highway speeds on paved roads. With the exception of non-brake based traction control systems, almost all electronic driving aids are somewhat less than efficient, and/or effective in the off-road environment. The only driver assist systems you are likely to need are traction control based on torque distribution and NOT the ABS system, diff locks on both axles, hill descent control, and of course ABS, since there are almost as many animals in Africa that wander the roads (paved and unpaved), as there are pedestrians and cyclists. However, with regard to ABS, it is always a good idea to have some sort of system installed with which to de-activate the ABS system on loose or slippery surfaces. Using the ABS on these types of surfaces could mean that you effectively have no brakes; therefore, you need to have some means to deactivate the ABS in circumstances where it could be dangerous to have it in operation.
These angles refer to the angles between the contact points of the tyres on the road and the point on the vehicle that will encounter obstacles first. Obviously the larger these angles are, the easier it becomes to negotiate large or steep obstacles; however, these angles are determined by the design of the vehicle, i.e. the amount by which the bodywork extends past the wheels, as well as its ground clearance. Thus, the thing to do is to choose the vehicle with the biggest approach and departure angles, but NOT at the expense of reliability and fuel economy. Nine times out of ten, you will be able to find a way around steep obstacles, but there is no way to increase fuel economy, or make a vehicle more reliable.
It the option to fit factory approved long-range fuel tanks exists, fit them by all means, provided of course that they do not diminish ground clearance, or are left unprotected against damage by flying stones or other road debris. On the other hand, the temptation to fit homemade fuel tanks, or any fuel tank that is not approved by the manufacturer should be resisted, because of the risk of irreparable fuel leaks, or worse, fires caused by fuel leaks. Carrying extra fuel in jerry-cans is always safer than modifying any fuel system, and while Africa does not offer a refueling point every few kilometers, filling stations are not so far apart that you risk running out of fuel every few days- all it takes to always have enough fuel is some careful route planning, and using every refueling opportunity that presents itself.
The off-road conditions in Africa demand steel wheels and no matter how strong the manufacturers of alloy wheels claim their products to be, no alloy wheel can withstand the ruggedness of Africa for long. The only real choices you have with regard to steel rims lie between solid and split rims, and both have their advantages and disadvantages. Split rims may make tyre repair easier, but solid rims can carry wider tyres, which is what you need for maximum traction. However, most Africa overland expedition vehicles use solid steel rims, because they are usually lighter than split rims, and offer the same, if not superior structural strength. The correct choice of tyres, however, is slightly more complicated.
Mud terrain tyres, for instance, work best in muddy conditions, but not very well in sand or on paved surfaces. Similarly, sand tyres work best in sand, but they are less effective on all other off-road surfaces, as well as paved roads, and while mud tyres can be used in sandy conditions, sand tyres do not work at all in mud. Clearly then, the choice of tyres must be dependent on the type of terrain you are likely to spend the most time on, but Africa offers all possible conditions all of the time, but fortunately not everywhere at the same time, which makes it possible to base your tyre choices on the route you have planned out, at least to some extent.
Although the idea of a Trans-continental road network through Africa sounded like a good idea at the time, and even though full-scale construction had actually started in a few places, civil wars, revolutions, and political instability have ruined much of what had been achieved, with the result that especially in rain forest-covered equatorial Africa, much of the road system still crosses swamps that are capable of swallowing large trucks.
Careful route planning is crucially important in these areas to avoid the worst mud, but once out of it, your mud tyres will have a hard time of things on the sandy and even extensive paved roads further north. Mud tyres are not known for their durability on hard surfaces, and since you will likely not be able to replace your mud tyres with more durable tyres because there are not that many tyre retailers in North Africa, the next best thing would be to use all-terrain tyres right from the outset.
However, all-terrain tyres are not created equal, despite the fact that each of several dozens of manufacturers claims their product outperforms anything the competition has to offer. The purpose of all-terrain tyres is to provide maximum traction in muddy, sandy, and rocky conditions, as well as reasonable durability and handling on gravel and paved roads, but the reality is that some are better (or worse) in some of these areas than others are in similar conditions. The fact of the matter is that perfect all-terrain tyres do not exist: design factors such as sidewall construction, tread design and depth, width, composition of the rubber used, maximum load and pressure ratings, actual vehicle weight and inflation pressure, and a host of other issues all play a role in how effective a specific tyre is likely to be in any given situation.
For these reasons, it is impossible to recommend any tyre brand as opposed to any other brand, except to say that whichever brand you decide on, make sure it is a product of a globally recognised manufacturer. Nonetheless, all tyres have both weak and strong points, which make it crucially important to conduct in-depth research into the various issues that could affect the life of your tyres. In Africa, you are on your own; you are dependent on the tyres you have, and if you happened to have chosen the wrong tyres, you are in trouble: you are limited to the tyres on your vehicles, plus your spares, and that is it. There are very few places in the African hinterland at which to get new tyres, and even if you do find a tyre retailer, you can never be sure about the quality of what you are buying, so do in-depth research, talk to as many off-road clubs as you possibly can, and pay due regard to the opinions of persons who have experience of long African overland expeditions.
No overland expedition vehicle should ever have a load carrying capacity of less than 1000 kgs; however, this does NOT mean that you should load a vehicle to its maximum capacity if you are heading into the African hinterland. Maximum loads place extreme stresses on a suspension system, as well as severe limitations on suspension travel, which means that you stand a more than even chance of damaging, or even breaking leaf springs and coil springs.
Additional spring blades or larger diameter coils might be better able to cope with extreme loads than standard equipment, but that solves only one half of the problem: the other half of the problem has to do with the load ratings of the tyres, and while many, if not most tyres could probably cope with maximum loads on smooth, paved surfaces, a heavily loaded tyre might not be able to cope so well with uneven, rutted, and/or rocky surfaces. Moreover, given the fact that you are limited to the number of tyres you are able to bring with you, it makes good sense not to run your tyres at their maximum load limits.
Ideally, the actual load on an Africa overland expedition vehicle should not exceed 80% of its rated capacity, but there is as much debate about this as there is about which is the best 4×4, but think about the fact that once a vehicle starts to bounce up and down on an uneven road, only the suspension can stop the movement; and the heavier the vehicle is, the harder the suspension has to work to control the movement. While the tyres can help to absorb some of the load, it must be remembered that tyres are not designed for shock absorption, and still the best way to prevent suspension damage is not to overload a vehicle.
So, once you have decided on a suitable vehicle, bear in mind that the total, final load must include the weight of the driver and passenger, the canopy, a full tank of fuel, the drawer and/or slide system to keep your goods and chattels separated, as well as a minimum of three spare wheels. This will of course take up a significant percentage of the total load carrying capacity, and if it appears that you are likely to exceed 80% of your available capacity, rather add another vehicle to the party, or get an off-road trailer to carry the excess weight.
As stated before, there is no such thing as a perfect 4×4, or even one that can called, “The Best 4×4.” All 4WD vehicles have strong and weak points, and the trick in choosing the most suitable vehicle for an overland expedition through Africa is to choose the vehicle with the most strong points; however, strong points come at a price.
While the price of a vehicle plays an important part in this decision, there are very good reasons why some 4WD vehicles are so much cheaper than the average. These “4×4’s” are all imported from the Far East, and are made up of bits and pieces from several models, and even different brands that are no longer manufactured in the West: all are badly built, and have a well-established bad reputation for their lack of technical support, scarcity of replacement parts, as well as their extremely dodgy and unreliable electronics. These Chinese vehicles are in fact so bad, and potentially dangerous, that the U.S.A. and several Western European countries have placed blanket bans on their imports.
The only viable choices for overland expedition vehicles should lie between the globally recognized brands that are sold in multiple countries, and preferably those models that are sold in several markets without significant differences in specifications such as engine power, load carrying capacity, fuel economy, and the length and scope of their warranties.
The choice of 4×4 vehicle is one of the most difficult aspects of planning an overland expedition through Africa, and it requires the willingness to fully research each possible option, having a reasonable budget, and most of all, having the ability to exercise good judgement and common sense, and not to be swayed in your decision by salespersons chasing the proverbial quick buck in the form of sales commissions.
We wish you luck with your search!
PS “… or just get a Land Cruiser…:) “