Tyres

I didn't have to drive to a Bob Jane T-Mart to get the answer, just talked to a couple of car company chiefs.The actual price varies a bit, but they say it comes in somewhere between one star and 40 litres.How's that? Well, a full-sized spare can help a new car achieve a five-star safety rating but it can also gobble up as much as 40 litres of boot space. But, for buyers, the luggage loss can be offset by a very marginal improvement in fuel economy.I learn these surprising facts from Nick Senior, chief of Subaru Australia, as I test drive his ripping new Forester. It will be the Japanese brand's favourite car this year, and for years to come, taking over from the smaller but trendier XV in a reflection with our collective obsession with SUVs.Subaru buyers demand full-sized spares and that's what they get in the Forester, just like the BRZ sports car and all the rest. Toyota has ripped the spare out of its 86er twin - a decision about to be reversed for Australia - but there are plenty of reasons why companies do it.It saves them money, primarily. But it also means they have more space in the back end, which is important in baby cars and haulers which need maximum baggage capacity. A space-saver, or no spare at all, can also mean a 25 kilogram weight saving and that has a direct impact on economy.But there is a bonus in staying full-sized."A full-sized spare can help with rear crash protection," says Senior. "It's also a priority for a lot of people in Australia. They drive a long way and they want security."The full-sized spare debate has raged for years, fuelled by Holden's decision to make one an option in the VE Commodore and BMW's move to rough-rider runflat tyres across much of its range.It's true that flats are much less common today than they were in the past - I only had two in 2012 despite driving 150-plus cars over more than 100,000 kilometers - but you still have to wonder.I know I took an instant dislike to the Volvo S60 when I discovered there was no spare at all in the car, and I was dismayed to discover the cramped boot in the Subaru XV. The new Forester is better, but 40 litres is still a lot of space to sacrifice because the Japanese designers didn't think about Australian roads and owners when they were designing the car. 

It's getting to the point we need to replace the tyres on our 2004 Toyota Prado. It's still on the original Japanese Dunlop AP20 Brandtrek 265/65 R 17, which have been absolutely magnificent with no road noise and have worn extremely well. We want the replacement tyres to be the same. What do you suggest?

I have an 18-month-old VW Golf GTi that has only travelled 14,000 km. Just recently tyre roar has become an issue. It has always been there, but now is very loud. I have been back to the dealer and he believes it is the inside edge of the tyres wearing. Two mechanics I consulted seem to concur with the dealer. One said he regularly sees it with 3-Series BMW's and changes the camber from the factory settings to alleviate the problem. In my case it seems to be caused by the GTi being lower than the standard Golf by about 15 mm. Have you heard of this tyre problem with the GTI? Is it Common? How should I remedy this as the front inside edges are wearing faster than the rest of the tyre? If this is a design problem and what help can I expect from Volkswagen.

I have a 2011 Holden Commodore SV6 Sportwagon and maintain the tyre pressure at around 34 psi, but I have noticed feathering on the outside of all four tyres. Could you please advise?

I recently changed the alloy wheels on my 2005 VZ Holden Commodore from 17-inch to a 20-inch and lowered the car as well. After doing that I noticed the car ride is not smooth and I can feel every bump in the road. Is there any thing that I can do to fix it, or is that a common problem with lowered cars?

Or are you among the majority of drivers who check their tyres less than once a year? Goodyear has invented a tyre that inflates itself while on the move – which, it claims, will save drivers money due to more even wear and better fuel economyThe self-inflating system was unveiled earlier this year, but Goodyear has just announced real-world fleet trials of the technology. The tyre, awarded “best breakthrough” by US magazine Popular Mechanics, maintains the correct pressure via a valve mounted inside the tyre – but which pokes through a gap in the tread.As the tyre rolls, the deformation of the tyre flattens the tube, pushing air through an inlet valve. Air is released – or sucked in – as required. Although it will be on North American roads in trial conditions next year, it’s not likely to be available in Australia until 2014 at the earliest.“The concept has been tested and it works, we’re now just looking at bringing it to market,” says James Peate, communications manager at Goodyear Australia.“There would be a price premium but it’s too early to estimate what it would cost.” Goodyear’s North American division is developing the truck version of the technology, while its Luxembourg facility is developing it for passenger cars.The self-inflating tyre is just one of many advances in tyre technology in the past decade. In 2000, French tyre maker Michelin introduced “run flat” tyres that can be driven at low speeds, even when punctured.Other tyre manufacturers followed, but car buyers have been slow to embrace the technology because of their cost (they were initially double the price of regular tyres) and uncomfortably firm ride (because of the thicker rubber used in the sidewalls).Less than 1 per cent of tyres sold are of the “run flat” variety, Michelin estimates. Meanwhile, Michelin has been working on a "see-through" air-less tyre called the “Tweel”. The tyre has no sidewalls, the tread is held up by thick cross sections of rubber – but it is still in the experimental stage.

An Italian council official knifed the tyres of a disabled man’s car after being fined for parking in the disabled spot.Antonio Piazza habitually parked his Jaguar in the disabled carpark outside his office in Lecco, but became angry when police fined him and ordered him to move it, according to a report in The Guardian.Piazza was captured on CCTV shortly afterwards returning to slash the tyres of the disabled driver whose Renault had taken the parking spot. The report says Piazza had initially argued against being given a ticket, claiming he had parked there while giving a lift to a disabled person.However, under pressure from his poltical party – beleagured Silvio Berlusconi's People of Freedom, which is the subject of a slew of scandals and corruption claims – Piazza has now resigned from his position overseeing a housing agency."I made a mistake, but there are people who behave even worse,” he is quoted as saying in the report. 

I had predicted before the event at Sydney Motorsport Park that they would last only 10 laps, as the (formerly Eastern Creek) circuit is notoriously hard on tyres, just like Phillip Island.Ten laps is pretty much how long they lasted when we did a race run at the official test day in January 2011. But I suppose there were lots of factors that contributed to the longevity of the tyres last weekend. For a start, track temperatures were lower than in January and the newly resurfaced track has smoother tarmac and fewer sharp stones which means less ripping of the soft tyre.We have also improved the car to look after the tyres since then and I've improved my knowledge of the limits of the tyre and how to budget wear. The car was exceptional on Saturday and did everything I needed it to do to look after the soft tyre. We ended up getting 23 laps out of it which was actually more than we had expected.In the second Saturday practice session we did a race run to see where the tyre was at and how hard I could push it before it burred up. We only had an eight-lap run before an oil spill shortened the session, but it gave us a good insight into how much pace we could get out of it. We thought it would be good for about 20 laps. I talked with JJ (race engineer Jeromy Moore) and we believed we could get better life than nearly everyone else so we gambled on pitting early. Then it was a matter of how I nursed it to the end.The Creek has some really fast long-loading corners and you need to preserve the tyre in those sections. Also, like Phillip Island, the front right-hand tyre cops all the punishment, so you have to be mindful of not scrubbing the tyre going into corners just for the sake of a millisecond of pace. It was an amazing result to come from sixth to the top step of the podium.Of course, we handed over all our data to the other side of the garage at the end of the day and on the Sunday my teammate Jamie Whincup basically ran our Saturday race to win. We also had a faulty rattlegun in the first pit stop which lost us a couple of seconds which we never got back. We were running at exactly the same pace as Jamie, but we just couldn't make inroads and still preserve our tyres.In the end I was happy with the weekend and pulling about 100 points out of the gap to first. There's now only 154 points between first and fourth and I'm breathing down Will Davison's neck for third. I was also pretty happy with the crowd of 24,000-odd for the return to Eastern Creek.It's a proper permanent racing circuit and there are precious few of them left in the country, so we need to keep it on the calendar. The Creek has never pulled huge crowds, but they are always the V8 diehards and it was very hectic with the fans in the pits. Everyone I spoke to was talking about how great it was to have the circuit back on the calendar. 

Eastern Creek is always tough on tyres and I reckon the softs will last only 10 laps. That means a totally different strategy approach to previous events where we started on hards, pitted early and hung on with the softs to the end.We haven't raced at the Creek since 2008, but I've had five race wins there, including Triple Eight's first V8 Supercar race win in 2005, and I've done pretty well with qualifying.We were last there in early the 2011 tour the pre-season launch and test day and we were fastest on the soft tyre, so I should reasonably expect I can get the car on the first two rows off the grid.If that's the case, we'll start on the soft tyre and try to gap the field before having to pit and change to the hard tyre for the rest of the race. Tyre wear will be a real unknown for everyone as we've never raced on the soft tyre there before. Also, it has usually been in hotter conditions which tend to shred tyres a lot quicker.So with the tyre wear uncertainty and less probability of safety cars at the Creek because of the vast run-off areas that encourages starting on softs which is totally opposite to the trend this year. However, there could be several different strategies in the field, so it points to some interesting racing this weekend.It has often been difficult getting fans out to the Creek because of a lack of public transport, but I hope we get a good crowd. I think we're returning to the Creek as part of a deal with the NSW government which would only support the Homebush finale if we raced at the newly upgraded circuit.They've spent something like $16m on the upgrades with some track changes and resurfacing that will encourage more passing and better facilities for the fans. I got a chance to drive on it recently and I suspect we'll break Mark Skaife's long-standing lap and race record times this weekend. This is the first two-day event with practice, qualifying and racing all on the same day. So any engine dramas like we had in practice at Queensland Raceway can be very damaging to your championship chances. However, it should be good for the punters as they will see more each day than just one qualifying and one race.While my focus is on this weekend and I always only focus on the next round, I attended the launch of the Gold Coast 600 this week and it got me thinking about the coming enduro events with co-drivers who can have a big effect on your championship.I've got Warren Luff for the Sandown and Bathurst enduros who has vast experience in V8 Supercars and who I've partnered in the Audi R8. At the Gold Coast I'll be with Richard Lyons who drove with us a couple of years ago in Bathurst. He's Irish and has spent a lot of years in GT racing in Japan, so I think he'll go fine. I'm confident he knows the cars and will be fast, solid and won't take any risks. My co-driver from last year, Andy Priaulx, has a clashing event in Europe and I'll miss him. In his absence, the best of the internationals will be Sebastian Bourdais who is co-driving again with my teammate Jamie Whincup. He was very quick last year and has driven there a number of years in the Indy race.