When I started working down the country at the start of the year and had to fill in hours listening to, or watching (in the background), the in-room TV I caught a short filler on ABC TV about the general increasing laziness of people’s driving habits. Before I go any further I will note that the article was about drivers in the US, however it is my observation that most of what they discussed applies to many drivers I have encountered.
In particular there were two items they covered that I found myself nodding my head to. The first of these was what they referred to as ‘static steering’ and the other related to preparing to turn left (which for us in Australia means ‘preparing to turn right’).
In this post I am going to relate a bit of what I can remember about what they said in relation to static steering. If I don’t forget I will cover the ‘preparing to turn right’ topic in another post.
Static steering refers to turning the steering wheel, and therefore the front wheels of the car, when the car is not moving (i.e., it is ‘static’).
I can clearly recall my dad telling me over and over as I was learning to drive, not to turn the steering wheel if the car was not moving. This was hammered into me. If you are going to turn the wheel then the car must be moving forwards or backwards—it cannot be stationery.
The reason for this is pretty obvious. Turning the steering wheel while the car is not moving puts incredible strain and stress on the steering gear. Even if the car is moving forwards or backwards at the slightest of speeds, even just barely moving, this provides significant relief for the steering mechanism.
Additionally, in those days before power assisted steering, trying to turn the steering wheel without the car moving was a challenge in itself. You needed to really pull hard on the steering wheel. You could tell it was probably not a good thing to be doing.
The issue is that with power steering now being common in even the base models of almost any make of car, it is now possible for the driver to easily turn the wheels from one lock to the other while the car is stationery—providing the engine is running. However doing this is a really bad idea; but the driver doesn’t get this ‘bad’ feedback because it seems like it is really easy to do.
It seems that the problem is that power steering has lulled us into thinking it is ‘easy’ to turn the wheels while the car is not moving. Nothing could be further from the truth. According to the presentation I watched (well half watched and half listened to) turning the wheels on a modern car puts about double the strain and stress on the steering linkages that it did 40 or so years ago.
How can this be? Following are a few of the reasons they mentioned that I could remember when I made the notes to make this post.
- These days the tyres on even the lowest model cars are significantly wider than they were in the 70s. Typically 30 to 40 percent wider. Wider tyres means more rubber on the road which means they are harder to turn when not moving.
- Almost all modern tyres are side-to-side radial ply with metal banding. In the ‘old days’ they were 60 degree cross-ply. Radial design tyres are designed to lay flatter on the road and to flex more, whereas cross-ply tyres are stiffer and more rigid. A more flexible less rigid tyre surface means harder to turn when not moving.
- Up until about the late 70s most tyres had tubes in them to hold the air. Today if you asked a tyre service station to put tubes in your tyres they would probably have to order them in, and in most cases they would have to change your tyres to tyres that could be fitted with tubes. Tyres without tubes are less rigid. Again, less rigidity means harder to turn when not moving because the tyre flexes more sideways.
- Today the average tyre pressures for the family car would be around 28 – 30 psi (pounds per square inch). Sports cars, with accounts for about 10 percent of cars sold (so they said) typically have tyres that run on 22 – 24 psi. Forty years ago tyre pressures were 40 psi and higher. Less pressure in the tyre provides a less solid tyre, which in turn means it is harder to turn when not moving.
- Modern ‘rubber’ is much more grippier [okay, probably not a word, but you know what I mean]. The rubber compounds are softer and have other compounds added to increase further their grippyness. These high-technology extra-grip compounds make turning the wheels when stationery even harder.
- Talking about high-technology, the computer designed tread patterns used for modern tyres are amazing. They make taking a 30 degree bend on a paved road at 120 kph (about 70 mph) seem easy. But these awesome high-technology tread designs are murder when it comes to turning the wheels when the car is not moving.
- The last point they made that I can remember is that 40 or 50 years ago the driving surfaces, and the surfaces used for carparks in particular, were much different to now. Carpark surfacing has improved significantly. 50 years ago the average carpark surface was slippery compared to the surfaces used now. In the case of concrete carparks most surfaces now are machine brushed or criss-cross cut to improve traction. 50 years ago many carparks were just compacted earth or gravel, either of which were much easier to static steer on—should the need arise.
“So, if you want your steering to stay tight and responsive, and you want to avoid visits to your friendly service station to see why your steering wheel has developed an annoying rattle or unexplained noise when turning, and you don’t want to find out you need to buy replacement parts for your steering gear for what you thought was a wheel balance problem, then don’t turn the steering wheel when the car is not moving unless you are parked on an ice rink or a wet muddy road” … [that’s what they said, or as close as I could remember it when I wrote it down]