When is the speed limit, not the speed limit…?
I sometimes like to just go and drive for no particular reason – just for something to do, when daytime TV gets too much to bear (Re-runs of The Professionals, anyone? There’s a limit to the number of times I can stand a Capri haring around sounding like its got a bad case of emphysema.)
Any AROnline readers who have read my previous articles will know that I am one of the ‘chuck it out’ brigade. I prefer the technology in a car to have a reason for its existence, not to be something that is put in just because it’ll beat the competition.
We get cars with radar-controlled cruise control for heaven’s sake and soon cars will be able to drive themselves at the touch of a button (and having seen the driving of some people in the fog recently, that’d be a very good idea). However, to be fair a lot of this stuff is window dressing so we can be convinced to pay over the odds (£1000 for an air-conditioning system that comes off the boat at £250 for example…).
Anyway, given all that, you would think that the most basic parts of the car concerned are accurate to the Nth degree wouldn’t you? Well, you’d be wrong.
I have many interests in my life – one of them happens to be computers. I’m one of those people who bought the original smartphones (you know, the ones the size of a housebrick, with the battery life of an anemic amoeba) and I love to tinker. I recently found a programme on my Android phone (mention ye not the iGullible) that recreates an aircraft head up display, complete with speed, inclination angles and a settable artificial horizon – so I thought I would try it out. It uses the ‘phone’s GPS receiver to produce course and speed data and the accelerometer in the ‘phone to produce the rest. Best of all, it’s free! There are even programmes that, through the use of a Bluetooth dongle, will allow you to realtime interface with your OBD-II engine – and, in the paid version, will provide you with fault codes.
The car I have is fitted with cruise control, which is very useful in an area where the Traffic Police are rabid, and I usually set the cruise when in a 30mph limit to exactly that… except for the fact that the most basic part of the car is actually wrong. 30 mph on the speedometer of the car is 28mph on the GPS – 32mph on the speedometer reads at 30mph on the GPS. This piqued my curiosity… so I took the car for a brief blast up the local piece of dual-carriageway (the A12) and, lo and behold, at a stated 70mph, I was actually doing 66mph. Furthermore, as my speed increased, the difference between actual and stated speed increased – to get a GPS speed of 70mph I had to be doing 78mph on the car speedometer!
Car manufacturers have managed to computer control engines, brakes and even suspension for years. They have installed Voice Warning systems, automatic lighting (since the late 1950s no less) and all sorts of other gubbins – ooh, look a button for the heated steering wheel – but they can’t even provide us with an accurate speedometer! All it would take is a board with a single chip GPS receiver on it linked to the dashboard readout – it’s not beyond the wit of a BMW engineer…
Now this might seem utterly unimportant at first glance but, if you look deeper, it’s highly significant and has an effect on a lot of different facets of driving.
Buyers are given a slew of performance data, on which to base their assessment of a vehicle and influence their choices. That’s fine, if any of it was correct. 0 – 60mph is all well and good, but it’s no use whatsoever if it’s really 0-54mph now is it? Then you have the fuel economy data – which is generally measured using presets – the best economy being at around 54-56mph, for which you are given figures, and again for simulated motorway work or urban driving… but, if the figures at 55mph are really measuring 50mph then we have another problem, they are downright wrong which, under advertising law as I understand it, is termed as misleading the customer…
However, that only deals with the problems when the speedometer reads (s)lower than the GPS ground speed. What could happen when the speedometer speed is higher than the GPS ground speed? What happens when you are in a potentially fatal accident and the Police’s calculations say you were breaking the speed limit – you don’t have a leg to stand on, even though you’re speedometer read 40mph the accident calculations say you were doing 45mph – that discrepancy could be the difference between 3 points and a prison sentence. All because an important system hasn’t been, and in a lot of cases can’t be, configured properly.
I think the car industry has spent too much time prettying up our new cars with the intent of getting more money out of us and, in the meantime, has spent far too little time applying the advances of technology to the basic systems of the vehicle itself…
Maybe, instead of trying to charge us £350 for a piece of two-core speaker wire and a USB port, they should try re-assessing the basics of the machines they are producing, so core functions are fit for purpose…