TYRES- Ken answers some of the most common questions.
Ken recommends the popular 4psi guideline.
1.Before a trip, when tyres are ‘cold’, pump them up to the recommended pressure as stated on the vehicle’s tyre placard. This is a starting pressure only at this stage. I also recommend that you purchase a good quality tyre gauge and use it each time, so you have consistent readings. Service station gauge readings will vary from place to place.
2. Drive for approx. ¾ to one hour so your tyres are at normal operating temperatures and check the pressures again. (preferably with the same gauge)
Your goal is to achieve a pressure after approx. one hours driving of 4psi above your cold starting pressure. If you achieve this on your first attempt, go buy a scratchy. Your lucky today.
If you have a pressure above 4psi from your cold starting pressure, your tyres have built up too much heat from friction and are underinflated. You should add more air up to the 4psi above cold start pressure.
If you have a pressure below 4psi from your starting pressure, your tyres have too high a pressure and you should let some pressure out until you have 4psi above the cold start pressure.
3. Repeat on your next trip with the new cold start pressure above or below your original start pressure depending on how much air you had to put in or take out to achieve the 4psi increase.
It may take a couple of goes but you will soon get a very accurate correct pressure for your car and van tyres that increases by 4psi after they reach operating temperature. Once you have established this pressure you can use it each time you check your cold tyre pressures.
My tyre guy in Bundaberg is Peter Walton and he and Cooper Tires recommend the same procedure but with a 6psi difference if using light truck tyres such as on a caravan.
Remember - incorrectly inflated tyres can be a major cause of dangerous caravan sway.
When should I change my van tyres?
Caravan tyres are tow along tyres and not drive tyres so do not attract as much wear as the car tyres.
This is where you should be cautious if buying a second-hand caravan.
“The tyres may have plenty of tread, so the tyres are OK”. WRONG.
The caravan tyres will deteriorate with age especially if they have been sitting in one place for a long period in the sun like many caravans. They can gain a flat spot. Once over 5 years old they are at risk of blowing out while on the highways. This can cause severe damage to the caravan floor and wheel arch or other vehicles if they blow out at high speed.
I had an old tyre blow out at about 95kph once, luckily on a dual axle van. By the time I could slow and find a place to pull over off the road the tyre tread had separated and rolled in between two oncoming cars. If it had hit a car going at 100kph it may well have caused a severe accident, injury and huge repair bill for my wife and I. Yes, it happened on a weekend, so it was also hard to get a replacement or four new tyres that day. My tyres were well past their use by date and should have been replaced ages ago. My first 2nd hand van and I learned from my mistakes.
Lesson 1, replace your tyres every 5 years whether they have good tread or not. I have just replaced 4 tyres and my spare that has never been on the road as it was 7 years old and original.
Lesson 2, rotate your tyres, including your spare, so you get some money’s worth out of the tyres you have purchased.
How do you tell how old your tyres are?
All tyres sold in Australia must have a date of manufacture stamped on the tyre.
Put simply, each tyre will have a DOT number followed by a stamped 4-digit number in a recess on one side of the tyre. It could be inside or outside.
The first 2 numbers are the week of the year it was made, (1 to 52) and the last 2 numbers represent the year it was made.
If the number was, as in the picture below, 1418 then this tyre was manufactured in the 14th week of 2018.
If the number was, for example 1215 then that tyre was manufactured in the 12th week of 2015.
Please check your tyres and tyre pressures so that you, your family and others can stay safe on our highways.
Remember to stay Truck Friendly. www.truckfriendly.com.au
Photo courtesy of Kwik Fit