WhichCar 2018 Tyre Test: The Basics

IF YOU’RE anything like most Australian motorists, the news that your car needs new tyres will create a sinking feeling. It’s the classic ‘distress purchase’, something that you buy out of necessity rather than pleasure. Around 23 percent of Aussies will buy the cheapest tyre available to them and half will wait until a tyre has reached its legal tread depth before replacement.

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But here’s the thing – it needn’t be that way. If you’re armed with the correct information, buying a new set of boots for your car could transform that way it goes, stops and steers for the better and also deliver a significant boost to safety.

The problem for most consumers is that the range of choice is truly dizzying. Even if you’ve settled on one brand, there are multiple tyre designs and models. What’s more, it’s virtually impossible to find decent, unbiased advice. Your local tyre depot is usually incentivised to push certain brands and will generally steer you towards the rubber with the chunkiest profit margins for them. That’s understandable, but in order to get the inside line on what tyres to look for, we’ve conducted a series of tests to bring you 2018’s best.

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And it’s worth paying attention. Without giving too much away, the difference between the best and worst rubber on the 2018 Which Car Tyre Test was a massive 8.6 metres (or two average car lengths) of braking distance in the wet, and we’ve all experienced that freeway hard stop where we wind up a couple of metres from the bumper of the car in front. Get this decision wrong and we don’t need to labour the consequences. So, on that vaguely morbid note, here’s how the test works.

THE METHODOLOGY

It didn’t take too much discussion to pinpoint the vehicle we wanted for the test. The Mazda CX-5 was Australia’s best-selling SUV last year and this Maxx Sport diesel version has a huge range of available tyre choices in its 265/65 17 size.

We also recruited test driver Renato Loberto as the guy behind the wheel. With a background in automotive engineering that has then seen him branch into event planning and management, driving instruction, and piloting a Ferrari GT3 race car, Ren’s a familiar face on sister title Wheels’ events and can be relied on for metronomic precision.

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The venue for testing was Sydney Motorsport Park or, to be more precise, the vast hotmix backlot of the Dragway where we’d set up a number of tests designed to objectively measure the performance of our fresh rubber. All of the tests were conducted with a Racelogic Performance Box GPS data logger and the Loberto was never aware which tyres were on the car at any time, staying in the vehicle when the wheels were changed.

After taking a tyre noise reading at a steady 60km/h cruise, the brand-new tyres were scrubbed in during a series of runs through a slalom. Renato ran through the series of 20m-spaced witch’s hats at an entry speed of 60km/h, whereupon peak lateral g-forces are measured. That’s followed by a dry braking test, entered at 80km/h, a similar wet braking test at the same speed and then a wet cornering test where lateral g is logged.

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The winner of each of the five dynamic tests was awarded a 100 percent score with the rest of the contenders given percentages based on how close they got to that mark. After all five disciplines were complete, the percentage scores were averaged and a final mark achieved. Therefore if one tyre were to win every event, it would end up with an overall score of 100 percent.

In order to ensure a level playing field, we ran some of the tyres twice across the day as ‘control runs’ so that we could ensure that conditions such as changing temperatures or the extra rubber on the track could be adjusted for if necessary. Each of the tyres tested is offered in a range of sizes, and although the results would by definition alter depending on tyre size and weight of vehicle, the results of this test are a decent indication of where you should spend your money.

THE WRANGLERS

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The task of swapping 68 tyres throughout the day was handed to the team from JAX Tyres, with all of the fitting equipment, ramps and air lines supplied by Eagle SMF Tyre and Automotive Equipment. In the space of a couple of hours, the otherwise bare scrutineering shed at Sydney Dragway was transformed into a very passable facsimile of one of JAX’s 80+ retail location

In order to keep things consistent, we ensured that all tyres were inflated to the CX-5’s placarded pressures of 38psi up front and 41psi at the back. Two sets of wheels on the go meant that as soon as the CX-5 arrived in the garage after a set of disciplines, it was a matter of a couple of minutes for the wheels to come off, ones shod with the next set of tyres to go on and the wheel nuts torque checked.

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Overseeing fair play on the day was our technical expert, James Whitbourn. He was the guy taking temperature measurements, collating Renato’s data and managing the running order throughout the day. An experienced WhichCar contributor with an engineering background, Whitbourn developed the tyre test formula for Wheels magazine and we’ve adapted it only very slightly for WhichCar.

THE FIELD

We wanted the widest range of tyres possible at a range of prices, so invitations were sent to all major manufacturers. Not all were able to get logistics in place, but a field of 13 original equipment (OE) replacement tyres for the 2018 WhichCar tyre test was comfortably the biggest set of tyres we’d ever tested in one day.

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The standard size for the CX-5 is a chunky 225/65R17, and many medium SUVs will run a tyre somewhere in that ballpark, with enough sidewall to avoid damaging the rim should you venture off the bitumen. As standard, the Mazda is fitted with Yokohama Geolandar G98s but we opted not to run these tyres on the day, given that they had seen a few miles.

Some of the tyres were household names. Even if you’re no petrolhead, you’ll probably know the Dunlop, Bridgestone, Continental and Goodyear brands. Others, such as BF Goodrich, Momo and Falken are familiar to those with a passing interest in tyres. Then there are the emerging brands that we were intrigued to try. Taiwanese outfit Maxxis is emerging as a brand going places, having claimed last year’s Wheels tyre test but many buyers won’t know too much about brands like GT, Laufenn, HiFly, Nexen and Vitora. Until now, that is.

Click here to see how each tyre stood up to our testing regime.