Skill in using a 4WD vehicle is really just commonsense – but it is commonsense that is either learned from real life experience of from heeding the advice from others. Unless you like learning the hard way, it is best to absorb as much as you can before you tackle sandy situations. Sand can be unforgiving. VERY unforgiving!
Before we get into the dos and don’ts of sand-driving, let me stress that the first and foremost requirement is respect for the environment. If you are new to an area, check whether local regulations permit driving on the beach or dunes. If there is no signage, ask people who live in the vicinity; enquire at the police office, or at any establishment that is likely to be frequented by people with access to the beach.
Even if it is ‘legal’ to drive on the sand, stay well away from areas that contain any sort of vegetation. Even if the vegetation looks unimportant to you, it may be essential for the stability of the beach and/or sand dunes. Similarly, stay off rocky areas as these may be the home for a wide range of small marine life.
Never drive between a fisherman and the water. You can’t see some fishing lines from a few feet away, let alone when you are approaching at ten miles an hour...and punching an irate fisherman on the fist, with your nose, is never pleasant. Similarly, watch out for people working on their tan. Most beaches have slight undulations that can obscure people who are lying flat - worshipping the centre of the solar system.
If you are driving over sand dunes, be sure that you look before you descend any hill. If you cannot see all the way to the bottom, get out and have a good look. Don’t charge over in the belief that you will be able to stop or turn if you see anyone, or a vehicle, on the other side. It may be too late.
What I have said for daytime sand-driving is doubly important for night travel. Any sand undulations will result in your lights, no matter how powerful, casting long, dark shadows – shadows that could hide obstacles, or people. Over the years, there have been several fatalities caused by 4WDs running over people who have been sitting, or lying, on the sand in the darkness.
In my opinion, one of the most important things that determine whether you travel over sand with ease - or with a lot of difficulty - is the tires on your vehicle.
Contrary to general belief, and despite what some ‘off-road experts, will try to tell you, wide tires are not the be-all and end-all to success on the sand. Tall tires are the answer. It is better to have tall, narrow tires than wide, low-profile tires – however, if they happen to be tall and wide, then so much the better. You only have to look at photographs of cars taken in the first two decades of the 20th century. The reason they had very tall wheels and tires was simple: the ‘roads’ they had to travel on were mostly unsealed. So, in those days, a motor vehicle had to be designed to cope with a daily dose of dirt, gravel, mud and sand. Just the sort of surfaces 4WD owners go searching for today!
Soon after I bought my first 4WD, I was talked into buying a set of ten-inch wide Alliance Blazer tires. According to the tire salesman, these were developed for the Israeli Army and would (therefore) be absolutely ideal for sand work. It didn’t take me long to realize that, if the Israeli soldiers used them on their vehicles, then it must have been to dig trenches! The Alliance Blazers were wider than the 750 x 16 Dunlop cross-plies I had discarded. But, because they were much lower than the 750s, their ability in soft going was noticeably inferior.
The easiest way to understand the tall-tire theory is to imagine the shape of the area of tire that is in contact with the ground. In the case of the 750 x 16 Dunlops, the contact area would look somewhat rectangular, with the longer side running lengthwise to the vehicle. Letting some air out of these tires will increase the contact area width but, more importantly, it increases the length. Picture the contact area as invisible skis: the tall tire rolls along on long skis that are ideally shaped for the direction of travel; the wide tire, however, may not be. If the wide tire is substantially smaller in circumference (lower in height), it is easy to visualize the poor ‘ski’ shape that it is going to provide.
Reducing the air pressure increases the tire’s contact area and therefore reduces the force per unit of area. Thus, the greater the contact area you can provide, the less prone the vehicle will be to ‘sink’ into the sand. However, you also must have some regard for your tires. Personally, I do not like reducing the pressures on a heavy vehicle much below 15psi, unless the vehicle is stuck. Running tires at very low inflation pressures can cause damage from (a) the severe flexing (b) the heat that is generated, and (c) obstacles that can cut, or pierce the bulging sidewall. Plus, unless you have dead-locker wheels, you also risk the tire running off the rim.
If you intend to do a lot of sand driving, it is best to choose a non-aggressive tire. In simple words, one that does not appear to have a deep tread with lots of ‘gaps’. Generally, an aggressive tire is suitable for rock and mud work but requires plenty of care in sand. A tire with aggressive lugs will usually come to grief in soft sand if the wheels happen to spin, as the lugs will act like a dredge and dig in very quickly. The ideal sand tire is one that is tall and wide and has minimum tread. The hard part, of course, is finding a tire that meets the requirements of sand travel, yet is acceptable for most other 4WD situations. In my opinion, two tires that come close are the BF Goodrich All Terrain and the Bridgestone Desert Dueler. There are better ‘sand/highway only’ tires, such as the BF Goodrich Sport Truck Radial, but these have their limitations when you want to get back into the rough stuff.
You are the only one who can decide what is best for your vehicle – once you are familiar with the requirements and know the limitations. If money is not a problem, the ideal is to have two sets of wheels. One set fitted with sand/highway rubber, the other with something more aggressive, such as the B F Goodrich MT or Goodyear MT/R