Your questions answered: Why should objects in the mirror be closer than they appear?

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Not so much of a question, but if a driver loses their license, wouldn't it be a good idea to make them reset a complete learner’s exam? It's obvious that if you've lost that many points, then your driving isn't up to par and perhaps a refresher course is in order. – Malcolm

Answer: Hey Malcolm; this is actually a very sound idea. Most states and territories offer passenger vehicle license holders a pretty fair number of chances to learn from the occasional mistake, but it certainly doesn’t stop everyone from blowing through their entire allocation.

Taking NSW as an example, a driver who’s exceeded 13 demerit points can elect to take a holiday from driving via a suspension or continue to drive under a good behaviour period of 12 months with just two points to their name.

However, there is a provision in the regulations that requires drivers who have lost their licence twice in five years to not only retake a knowledge test, but to complete a safer driver’s course before their licence is renewed.

While I agree with your assertion that losing a licence even once isn’t good enough, at least there’s a provision to make repeat offenders do a bit more work before they can get behind the wheel again.

You recommended a Skoda to one of your readers last week. Why on earth would you do that when there are cheaper, better equipped SUVs on the market? Do you own one? We had a Yeti a few years ago and it was a terrible car. – Jack

Answer: Hi Jack; no, I don’t own a Skoda, though I would put an Octavia RS wagon in the driveway tomorrow if I needed to replace my current car.

Look, it’s a valid question, because there are few things more soul-destroying than buying a car that repeatedly lets you down, and Skoda hasn’t been immune to issues over the years.

I recommended the Skoda to Marty based on my experience with not only the car in question, but with other models within the wider Volkswagen family. Is it a perfect car? No, but that wasn’t the question.

I recommend cars to people who ask me based on nearly three decades of experience and a genuine interest in seeing people get aboard the right car for them.

Sure, I’ve had any number of nice lunches and hotel stays over my career thanks to car brands trying to curry favour, but from when I started reviewing mountain bikes in the 1990s to today, I have genuinely never cared what the commercial ramifications might be about what I have to say, as long as what I say is based in fact and experience.

Doesn’t always make my editors happy, but that’s why they get the big bucks. I’m paid to call it as I see it.

So, why do my mirrors have ‘objects in mirror may be closer than they appear’ written on them?  Why can't I have a mirror that accurately reflects what is actually there?

And while I’m here, why can't I get a speedo that is actually accurate? Every car I have owned has displayed about five percent more than the actual speed. I know this because I have tested them all against multiple satnavs. – Dan.

Answer: Hey Dan, great questions. I haven’t seen too many convex rear-view mirrors in the last couple of years, but you are right; they were certainly a feature on a lot of new cars over the last decade or more.

The idea is that the bowed mirror widens our view, and it’s supposed to fill in the blind spot blanks especially down the passenger side of the car. But, as you point out, the drama is that the distorted image can trick the eye into thinking objects are smaller. Combined that with a conventional mirror on the driver’s side and it can be a struggle to adapt.

Depending on what car you have, though, it’s entirely possible to replace that convex piece with a factory-spec flat mirror from a similar model car; I’ve done this on my parent’s old Lexus, for example. It’s also possible to have a flat piece of mirror glass cut to size to replace it.

Speedometer calibration is a long and involved discussion, but suffice to say that Australian Design Rules mandate that vehicle speedos A) are mechanically connected to a wheel and B) have no more than a 10 per cent variance above real speed.

The reason that speedos don’t read correctly in real life comes down to wheel diameter. Cars are homologated (designed for, basically) with a number of wheel/tyre combinations, which will all have a slightly different overall diameter.

A 17-inch rim with a 255/55 series tyre will roll 447 times in one kilometre, for example, while a sportier 18-inch rim with a 265/45 series tyre will roll 458 times, which is about a two percent difference. This is why your speedo will read slightly differently to a GPS-based figure, which plots your course over a minimum of three points.

Legally, your speedo can’t read lower than the posted speed, which can happen if you fit oversized wheels and tyres. And why can’t we use GPS for speedos? It’s not guaranteed that we can always been in line of sight of GPS satellites; tunnels and cities are an obvious issue for starters.

The views stated in this advice column are advisory only. Questions may be edited for clarity and length.

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