General Thoughts / Random Observations

The perfect tyre has not yet been invented and probably never will be as shortly we’ll be hovering from A to B in our electric drones. Just how I’m going to get the boat and camping gear to the beach I’m not sure!!

Tyre design is all about trade-offs. If we go for low noise and grip (soft compound) then we sacrifice mileage. If we focus on mileage (hard compound) then we have slippery in the wet (water is the natural lubricant for rubber) and harsh riding. But – – more on this later.

Tyre costs can vary wildly. I don’t mind paying more for something If I’m going to get more. Sometimes you can pay more for a tyre and get less mileage, or, more road noise. It’s all about perception and clever marketing. Some people buy on brand and that’s fine. We’ve all bought Jaguars! But just be aware those tyres may not be the best value for your dollar given our Nana speed limits (sorry Nanas).

For example; Michelin, Pirelli, Bridgestone etc. sponsor motor racing very heavily the cost of which has to be recouped. This is the premium you pay in order for Lewis Hamilton to become F1 world champion again. Then – as the saying goes “win on Sunday sell on Monday”. If Pirelli (or Holden) win in the weekend then they expect sales to go up and the Marketing people cash in on this by adding another premium on top of the last one! But – – more on saving money later.

Tyre choices and options are huge as we all have different wants and needs. This makes the decision as to which one to use more difficult. The hardest decision to make, however, is what exactly do you want and / or expect from your tyres. Just because the car manufacturer specifies a size and style you don’t have to stick with it. Their decision is based on price and quiet comfortable running, unless it’s a Jaguar then they also have to factor in performance!! They are certainly not worried about mileage and NZ road conditions. But – – more on this later.

Tyre type choices is easier for cars as they are on road only in which case it’s only standard , high performance or snow / ice. However, it’s more difficult for 4×4’s and SUV’s as they can go from HP ( high performance ), HT ( highway tread ), AT ( all terrain 80/20 , 50/50 , 20/80 ) to MT ( mud terrain ) and snow / ice. Then we have LT (light truck) for load carrying on utes, caravans etc. But – – more on this later.

Tyre sizes also vary hugely. The vehicle manufacturer specifies a size based on diameter (gearing and brake clearance) and width (traction and lateral forces) both of which we can change depending on our choices. The width doesn’t normally change much unless it’s for appearance. Putting a wide tyre on gravel doesn’t work too well and we’re not supposed to be driving so fast around corners to require more lateral grip than the OE (original equipment) tyres provide.

The diameter, however, is another story. If you add more power than the gearing can be upped to reduce engine revs and noise for more cruisey motoring at the same speed. Or – gear down for acceleration and pulling power at the expense of top end speed.

Also – for diesel engine vehicles we can save money by increasing the diameter. The mileage tax is based on distance covered and the speedo / distance meter is normally driven by the driveshaft revolutions. Most speedos over read. An indicated 100 km/hr can be only an actual true speed of 95 km/hr and consequently less distance travelled. In this case by 5%.

So, the Government is getting more tax from us than we have paid for! Therefore, using a larger diameter gives a larger circumference so for the same number of drive shaft revs the vehicle will cover more ground. If then we assume an allowable tolerance of +/- 2% in diameter and add that 2% to the 5% then we could achieve 7% more k’s for our dollar. But – – more on this later.

Tyre maintenance is another major factor in the cost of our motoring. In some respects, the tyre business is a good one to be in, as a lot of vehicle owners don’t care for their tyres, causing them to wear out prematurely. Even with good care tyres must wear out as there would be no grip if they didn’t.

The best retail business to have is one were you have repeat customers – especially if the law says you must spend. The tyre business is a good one then as you have to keep going back to the shop every two or three years. You have to spend the money or you don’t get a WOF. There’s no choice. It’s a “must have”. Not a “nice to have”. Tyres, therefore, are a real begrudge buy.

People are happy to spend thousands of dollars on rims (the metal centre piece) but struggle to pay hundreds for the tyres despite the fact these are doing all the work in keeping you safe. But that’s just human nature. Note: rim plus tyre = a wheel. You can have all the power, massive breaks, traction control aids etc. but it all comes down to the contact foot print between the road and tyre – – times four. If the grip is not there then you’re off into the weeds!! But – – you guessed it – – more on this later.

In the meantime, safe motoring and check your tyre pressures.

By Gary Bexley