Wheels and Tyres can be matched for most, but not all vehicles.

The devil is in the detail, and with more vehicles coming to market with 17" and 18" wheels there are additional issues to consider like sourcing 18inch tyres in the outback?

These are the important factors for consideration:

  • The hub pattern with the no of studs and the diameter of these
  • If the diameter of these studs is less than 139mm, then the larger 2 tonne axles wont fit through this narrow diameter
  • The hub face to wheel offset needed to match your vehicle
  • The final tyre size you want to use to match the vehicle
  • The way the alloy wheels are secured to the hub and the right wheel nuts to secure the alloy wheels

The hub pattern and the wheel offset need to match.

This can be done for most vehicles.

The coding will be something like 5x14mm on 150 HYD +50 which means 5 stud with 14mm threaded studs on a 150mm diameter Pitch Circle Diameter stud pattern with a 50mm positive offset to the face of the hub from the wheel.

Kimberley have more than 10 combinations available here.

With 2 tonne bearings used in Kimberley Karavans and Kampers, the minimum PCD is 139mm. This means vehicles like BMW, some Mitsubishi, some Land Rover and some other brands that have small PCD wheels can’t be matched to any hub with 2 tonne bearings.

The Wheel Nuts have to match the Wheel.
There are many types of wheel nuts and alloys in particular have a different style of wheel nuts to steel wheels. If you have specified that you will provide your own rims, then you will also need to pay attention to the wheel nuts as the transporter wheels are steel and steel matching wheel nuts are shipped with these.

The thread type has to match. Traditionally most electric drum brakes (sourced from USA) have a UNF thread and this is an industry standard. You have to specify the right metric threads to match vehicles with metric studs (most these days)

If you are travelling in off road conditions, it is a saving in fuel economy as well as easier to manoeuvre if the trailer wheels tracking width is as close as possible to the vehicle.

For all regular large caravans, this is impossible to achieve as the width of the van and the wheel track is far wider than the vehicle. It is one of the major reasons to specify a Kamper or Karavan for off road use. However, don't worry about a few millimetres over or under. Generally getting within 50mm is quite OK. Kimberley match within 2mm or so on the traditional 100 series Landcruiser and the Nissan Patrol. But the front tracking width on most 4WDs is different to the rear, so you cant match both size with one axle, so it just has to be close.

camper trailer design guide

Optimize Tyre Pressures - Download the Book

camper trailer design guide

Matching Wheels and Tyres research Book

camper trailer design guide

This book has more detail on matching wheels and tyres

The final tyre size you want to use to match the vehicle.
This is the most important matching as tyres can always be swapped from rim to rim. However, with the onset of 17" and 18" tyres, a far more important practical factor is the air volume size in the tyre.

If low profile 18" wheels are used in off road conditions, you have a very small air volume for cushioning in the tyre. You also have a significant disadvantage when you deflate your tyres for sand work as the increased footprint from the deflated tyre does not increase as much as it does in a normal profile 16" tyre.

For 18" tyres they cannot be less than the size profile fitted to the vehicle which in Toyotas case is 285/60.

Matching 18" Wheels & Tyres for your Kimberley Offroad Camper Trailer or Caravan

It is understandable that customer want matching wheels and tyres on their Kimberley to their vehicle but there are problems with the larger 18" wheels that you need to be aware of. These problems are not specific to Kimberley but relate to low profile, large diameter rim tyres off road.

Our design rule is that the suspension forces on the towed Kimberley can be 3 x that on the vehicle. This is because of the pendulum effect, particularly at speed over road bumps and grid hazards. Be careful of any advice that suggests what is good for the vehicle will work for the towed unit. This is not the case!

When travelling on black tarmac roads there is no problem with any tyre, in fact stability is slightly better with low profile tyre.s (which is one of the reasons they have them in the first place, together with a smarter appearance).

However, in corrugations, the tyre pressure has to drop to 18-20 psi and these tyres do not have much of a captured air volume. They also do not increase the footprint size as much as the 16" normal profile tyres do. With lower air volume, they do not absorb the vibration from the corrugations very well. This creates higher transferred energy to the shock absorbers which if not checked could over heat. Our shock absorbers have temperature indications on them as a standard feature to assist with this.

The large alloy 18" wheels are also more exposed to gibbers and rocks on the following trailer and will be more susceptible to scoring and damage.

For 18inch wheels, there are 2 ways to go here:

  • Buy 18" wheels & tyres
  • There are few 4x4 5 stud or 6 stud rims easily available in 18"

Landcruiser 200

  • Size: 18 x8 Offset: +40mm PCD: 5/150

Prado

  • Size: 18 x8 Offset: +20mm PCD: 6/139.7

For the Tyres:

  • They cannot be 10 ply and cannot be low profile (less than the size profile fitted to the vehicle which in Toyotas case is 285/60)
  • The size fitted as standard on the Toyota Landcruiser 200 series is Dunlop 285/60R18 but these are not a good off road tread. They’re only a highway tyre with passenger construction, but they have a load rating of 116
  • The Yokohama Geolander 285/60/R18 A/T-S  116H G012 AT. .  It is a passenger construction tyre with semi off road tread pattern and a load rating of 116. 
  • There are no Cooper tyres we have found on a softer ply rating to flex for corrugations. Buy a set of 16" steel wheels and tyres for the vehicle and Kimberley Unit and use standard BFG 16" of your choice that are readily available in the bush. Use 16" steel wheels.

Alternatively just buy the wheels and tyres in 16" for the Kimberley using genuine Toyota Wheels. Although they are different tyre, the rolling diameter will be similar and you could comfortably fit these to the vehicle if required and drive some distance in an emergency. The latter is what we recommend.