Have you heard about the bloke that was living in a Tyre?! He picked up a puncture so now he’s living in a flat!
Tyre Manufacturing has changed unbelievably over the past few years, but Tyre basics are still the same.
One of the biggest changes I now see on Caravans that I Service, is most Tyre's are now Chinese Imports, fitted in the factory.
Whilst I wouldn't put some of these Tyre's on my Tow Vehicle, fitment on a Caravan at face value is OK. They are cheap to buy, so even if they get half the wear out of them, you will be in front.
We, as Australians, lost our last Tyre Manufacturing Plant in 2010, when a Japanese Tyre Company shut it down. That was a profit decision, without a care for the people or communities involved.
So lets help each other, I will report as to which Chinese Tyre's wear best, if you could also send in your input. We can then spend our hard earn dollars saved, Camping in our beautiful State, keeping our money Local!
Right, let's Talk Tyre's.
Why is tyre safety so important?
Your tyres are the only part of the Vehicle and Caravan that are in contact with the road. The safety of both yourself and your passengers along with the other road users, may very well depend directly on what condition of your Vehicle and Caravans tyres are currently in.
Tyre's must:
Be the right type and size for your vehicle
Be properly inflated as per vehicle recommendations
Be free from any defects and have a minimum tread depth of 1.6 mm
The dangers of using sub-standard or incorrect tyres include:
A Reduction in road handling leading to a loss of control whilst driving
An Increase to braking distance meaning it could take anything up to twice the normal braking distance to stop the vehicle
Aquaplaning, where your tyres can lose grip on the road in wet or damp conditions
Blow-outs that can also result in loss of control
Tyre Age
Even unused tyres perish over time especially those
exposed to
heat, sunshine (UV radiation) and salt spray. Tyre's are marked with the production date of the tyre and understanding these marking can help you determine the age of a tyre.
Spare tyres fitted to Caravans are often exposed to the elements and can age prematurely.
It is recommended that you do not use tyres more than 6 years old from the date of manufacture. If a tyre has been in use, it has been reported that the effect of ageing has been lessened to a degree, but depending on the wear they should be replaced before 10 years. If you are in any doubt about the age and wear of a tyre discuss it with a tyre expert or replace it.
How do I tell the age of a tyre?
Tyre's carry a DOT number on the sidewall that gives a production date. Since the year 2000 the numbers consist of 4 digits instead of 3. The first two digits indicate the calendar week of production and the next two the year of production.
Eg: 3004 – the tyre was manufactured in the 30th week of 2004.
For tyres manufactured in the 1990's there is a little triangle ∆ after the DOT code. Eg: 4 2 8 ∆ - the tyre was manufactured in the 42nd week of 1998.
If the tyre has a three digit code then it is too old.
Tread Wear
Keeping a check of on the wear of your tyres can increase their life.
Follow the 4 PSI rule and have the wheels balanced and rotated on a regular basis.
What is the 4 PSI rule? It's a general rule a bit like the "Pirates Code", but an industry accepted guideline.
The following can be used - for road use only: For passenger tyres, inflate your cold tyres to the recommended tyre pressure on your vehicle’s tyre placard. Then to determine if you have the correct pressure for a given load, note the cold pressure reading. Drive for at least 20-30 minutes to ensure they have reached operating temperature and then check again. Ideally, they should be about 4 PSI above the cold pressure. If the pressure is more than 4 PSI above the cold pressure, you should add more air. That is because there is too much friction, which builds up more heat than desirable. Conversely, if they are less than 4 PSI above cold pressure, the cold pressure is too high. Adjust your pressures accordingly.
For Light Truck and 4WD tyres, use 6 PSI as a guide, but rough and corrugated roads cause more flexing and your tyres may rise more the 4 or 6 PSI. In which case applying this “rule” is not recommended.
The tread wear indicator is the bump inside the groove. When
tread wear indicators touch the ground as the wheel turns, the tyre needs replacing.
Tyre Markings? Those Numbers on the Sidewalls.
Tyre Markings/Tyre Sizes
If you take time to look at the side wall of your tyres, whether they be on your 4WD vehicle or Caravan, you will find a great deal of important information.
Each tyre will have distinct markings. Light truck (L/T) tyres are often used on 4WD vehicles and Caravans.
Terms:
P = passenger car tyre
There are other types as well ie: ‘ST’ or Special Trailer and ‘LT’ for light truck tyres. There is also a truck or bus tyre which has no prefix like 12Rx22.5 LRH.
205 = (width) is the metric measurement across the widest portion of the sidewall (section width) in millimeters.
/ = The slash is the mathematical term indicating ratio.
65 = (height of side wall) the mathematical result of dividing the section height (depth of the tyre cross-section from the tread to the bead) by the section width (see above). This may also be referred to as the profile or series of the tyre. Eg: low profile or 70 series tyre. Ratios approaching 1 are generally associated with high carrying capacity and lower speed while low ratio .70 to .35 generally are towards a high performance capability with high speed and handling quality. In this case, the tyre height is approx 75% of the tyre width.
R = an alphabetical term for a radial tyre. In a radial tyre the cords run perpendicular to the bead of the tyre directly across the crown to the opposite bead.
16 = (rim diameter) this numerical number is the diameter of the bead of the tyre in inches. Bead seat diameters are manufactured in ½ inch increments. This tyre is designed to fit a wheel with a 16 inch diameter.
95 V = load/speed index (see load range below). A speed designation at which the tyre can carry the load corresponding to the Load Capacity Index.
Car Tyre Speed Ratings
Speed Symbol Maximum Speed(km/h)
L 120 M 130 N 140 P 150 Q 160 R 170 S 180 T 190 U 200 H 210 V 240 Z 240 W 270 Y 300
M + S = meets the Rubber Manufacturer’s Association standards for a mud and snow tyre. These can also be recorded as combinations such as M/S or M&S.
Tyre Maximum Load Rating
‘LR’ is the load range and the ‘D’ is the defined carrying capacity.
The higher the letter in the alphabet, the higher the carrying capacity.
The load range codes relates to the old system of plies. For example, ‘D’ is the 4th letter of the alphabet and multiply it by 2 (4 x 2 = 8) or 8 ply ‘rated’ tyre. (Another example is ‘E’ which is the 5th letter of the alphabet (5 x 2 = 10) or 10 ply). This shows us that the more carrying capacity we need the higher load range we require.
Load Range (LR) D = (8 ply rating) is the load carrying capacity of the tyre. (eg: D = Load Index 110, E = Load Index 116)
Max Load Single 1380 kg (3042 lbs) @ 65 PSI COLD
Max Load Dual 1260 kg (2778 lbs) @ 65 PSI COLD
‘Max Load’ = the maximum load capacity of the tyre. Operating a tyre over its rated capacity may damage the tyre internally.
‘Single’ = is the stated capacity when the tyre is installed in a single tyre application ie: one tyre on each end of an axle.
3042 lbs = rated carrying capacity of the tyre in pounds when installed in a single configuration.
65 PSI = the minimum air pressure required to obtain the carrying capacity of 3042 lbs.
If you reduce the inflation pressure the rated carrying capacity decreases. (Tyre pressure is measured in kilo-pascals (kPa) or pounds per square inch (PSI).
"COLD" = this is the inflation pressure of the tyre cold, that is the tyre temperature before you commence a journey. See above for explanation of 4 PSI Rule.
Tubeless = has no rubber tube. The tyre seals on the rim via the bead and it has an external valve.
Treadplies = rubber coated cords forming the ‘footprint’ of the tyre.
Polyester cord = a synthetic fiber that maintains strength properties at high heat levels and eliminates flat spotting.
Tyre Load Rating
Index Number Maximum Permissible Load (kg)
60 250 70 335 80 450 90 600 100 800 110 1060 120 1400 130 1900
Did you know that as part of every Service
Inspection Westcoast Trailer and Caravan Services checks and adjusts Tyre Pressures, inspects rims and condition of Tyre's- including spares?
