If feasible, (and it often is), have the same size and type wheels and tyres (and track width) as the tow vehicle. This enables you to interchange spare wheel/s in the event of tyre problems, thus providing extra security when travelling in remote areas. Most trailer makers can supply hubs of the required wheel stud size, number and spacing.
The above is feasible with ‘space saver’ spare wheels, but many cars no longer carry any form of spare. A few have ‘run-flat’ tyres. These are good for about 70 km, but of no value half way down the 1000 km Tamani Road.
Most camper trailer tyre problems are due to gross overloading, and/or running at incorrect pressure. Consider going up one size: 215 x 85R16 to 235 x 85R16 and/or fit Light Truck six-ply versions of your current size. It is legal to do either, and preferably both.
Don’t economise by using low-quality or unknown brands.
All tyres absorb oxygen. This is normally pumped out by driving, but, if tyres are unused for a few years, it remains fixed, causing tyres to slowly disintegrate. All have a maximum life of 7-10 years regardless of wear – or even unused.
Many lower-priced camping trailers are supplied with second-hand tyres. The buyer is rarely told that. It is advisable to query this as you can usually pay a bit more for new ones. If you are considering outback travel – don’t even think about using second-hand tyres.
The code shows date of manufacture. This tyre was made during the 13th week of 2001.
A tyre’s age is indicated by a semi-obscure code usually low down close to the rim.
The code prior to 2000 had a final three-digit number of which the last but one digit indicated the decade of manufacture. Thus an ‘8’ indicated 1980-1989, a ‘9’ indicated 1990-1999.
In 2000 that changed to the sequence shown (left). The first two numbers indicate the week of manufacture. The last two show the year. The tyre shown here was made in the 13th week of 2001.
Inner tubes squirm around in moving tyres, generating heat as they do so. Tubeless tyres run cooler. Their makers advise against using tubes in such tyres except as a temporary measure. Michelin’s (steel-braced) inner tyres are particularly susceptible to this. If inner tubes are fitted, they must be genuine Michelin as few others withstand that movement, and may fail within a few months.
On soft sand, large-diameter standard section tyres almost always outperform smaller diameter wide tyres. Most Dakar Rally vehicles thus use Kevlon-reinforced (narrow) hi-tech 700 x 16s. This is also why country folk still prefer 750 x 16s – or the 235 x 16 x 85 close equivalents.
Large diameter, narrow-section tyres also reduce aquaplaning (i.e. sliding uncontrollably on water-saturated surfaces). Trailers are as prone to this as are cars – but the driver is unlikely to be aware this is happening also to the trailer.
Why tyres bog down in sand
A tyre in soft sand creates a constantly formed steep ridge that it must constantly climb, needing a lot power to do so. In really soft sand, that alone may bring a big 4WD down to first gear low range. It may possibly stall.
The greater the tyre diameter, and the higher its profile, the more pliant its footprint leading edge and the lower the pressure, the easier the tyre rolls over that apparent ongoing hill.
Rocks, rough, & dirt roads
Here, always reduce tyre pressures: this allows the tread to fold around rocks – not penetrated by them. The makers suggest reducing by 25%-30%, warning to keep speed below 80 km/h – or there will be excessive and damaging heat build up.
Most outback dwellers keep tyre pressures low all the time. It increases fuel consumption marginally, but they rarely have tyre problems. Some tourists even increase tyre pressures: doing that boosts Broome’s and Derby’s tyre sales every season!
For easing driving in sand, if feasible ensure your trailer’s wheel track (their distance apart) is the same as that of the tow vehicle’s. Then, the trailer’s tyres run in the just-made (and now consolidated) ruts. If the trailer’s track is different, the increased drag may bog you down.
(top) Lowering pressure causes the side wall to bag out but at far too high a level to be remotely useful.
(Bottom) By far the major benefit of lowering pressure is the elongation of the footprint. The larger the tyre diameter and the higher the side wall, the greater the effect. Pic. RV Books.