Stamp duty for cars explained
When you go to buy a new or used car, you will have to pay stamp duty. But what...
There's a good chance you're wrong and you wouldn't be able to get the wheel nuts off, but there's also a good chance you'll struggle to remember the last time you had a flat tyre at all.
Tyre technology, and in particular the strength of the sidewalls, has improved so much over the years that a flat is a far less common occurrence, according to Jack Haley, the NRMA's senior policy adviser on vehicles and environment.
"Most people haven't had a puncture for years," he says. "Tyre technology has improved, but there's also just not as much rubbish dumped on roads by trucks these days, with covered loads. Not as much debris."
If you do get unlucky, though, you might also find that you and your tyre spanner are not up to the job. "We're finding that a lot of people, even men, can't get the nuts undone, because they've all been done up by an air gun these days and they're just too tight," Mr Haley explains.
You don't want to be 300km from the nearest tyre centre and trying to use your space saver, because you'd wear it out before you got there
"They used to be done by hand, but everyone has guns now, for productivity, because it's quicker. Our roadside assistance guys have guns, too, so that's fine but if you try it yourself you might find you can even stand on your tyre iron and they won't budge. Go on, go outside and try it now.
"I've actually bought a piece of pipe as an extension for mine, so I can do it, but my wife still wouldn't be able to."
There are, of course, other options; many car companies now offer roadside assistance, much of it provided by motoring clubs like the NRMA, but some men find it emasculating to ask for help with a simple tyre change.
Not all spares are created equal
There are also a raft of choices when you buy a new car now, with full-size spares offered less often, or only as an optional extra, and many cars fitted with smaller, lighter space-saving spares or TUSTs (Temporary Use Spare Tyres).
Many more premium cars are also offered with run-flat tyres, which have harder sidewalls, which means they can drive for around 80km, at up to 80km/h, even after you've picked up a puncture.
Then there are the more expensive sports cars, with which you get less - no spare tyre at all, just a puncture repair kit, which is a can of "goo" that you can, hopefully, fill the tyre with, which will keep it rolling until you get to help. As long as help is quite close.
So which option is best, particularly in Australian conditions?
Full-size vs space saver
"If you travel long distances, a full-size spare is what we strongly recommend, you don't want to be 300km from the nearest tyre centre and trying to use your space saver, because you'd wear it out before you got there," Mr Haley says.
"You can't go past 80km/h on a space saver either, and they're skinny to save space so there's not as much bearing area for the weight of the vehicle, which does effect the handling, hence the lower speed.
"They're not good on a gravel road, and they will wear out, and I'd be most careful with them in the wet, too.
"Lots of car companies offer the space-saver as standard, but you can ask about a full-size spare, and it will fit in the wheel well, it just raises the rear floor a bit more, in most cases. You might have to pay for it, but Holden made it an optional extra at no charge when they introduced the space saver on Commodore."
Puncture repair kit
Mr Haley says the can of goo option is also very much an emergency fix only. "If you have an object in the tyre and you put the goo in, you might get 100 or 200 kilometres out of it, but it can be a bit tricky if you haven't done it before," he says.
"Luckily only sports cars, which are really trying to save on weight, tend to have the can of goo, and a few Mercedes-Benz sedans."
Benz spokesman Jerry Stamoulis says that only the company's sportier, AMG-fettled sedans have puncture-repair kits. "That's because of the type of tyres AMG uses, but almost every other car we sell now uses run flats, we're big believers in that technology," Mr Stamoulis explains.
"The sidewalls are so much tougher, they just don't get cut and ripped like they used to. But the good thing is, if something does go wrong you can keep driving and find somewhere to stop."
Mr Haley says the worry with run-flat tyres is that supply isn't good, and you might struggle to find a place that has one within the 80km your flat run-flat will get you. "They're also not a solution for all types of puncture, I've had cuts through sidewalls on gravel roads, so they're no good for that," he says.
The other issue, of course, is that if you get a puncture in a run-flat, you will have to replace it. Just as you'll need to replace your space-saver spare if you're forced to drive it more than 40 or 50km.
BMW, which was championing run-flat tyres back when Mercedes thought they were a laughable idea, also uses them on its entire fleet, with the exception of its sporty M cars (can of goo).
The company has long made a point of the safety advantage of run flats, which it thinks will eventually see them take over the motoring world. "People don't have to endanger themselves by exiting the vehicle and trying to effect repairs," as a spokeswoman put it.
Every year, tragically, around the world, people are run over and killed while attempting to change a tyre on a roadside verge, yet a run-flat driver never will. It might be easier, and safer, just to call roadside assistance, no matter what kind of spare you've got.