Thread: Diesel prices!

Originally Posted by Slunnie

The motors do have twice the power though

Yes. Not only that, but the amount of junk the engine has to provide power to has greatly increased - air conditioning of course is the biggest, but more and more powerful lights, power everything, heated everything and so on. Add to that, with the demands for "safety" and comfort the total mass of cars has increased dramatically in the last twenty years - airbags, extra wiring, increased structural strength, stronger seats, side intrusion bars, bigger brakes, much bigger tyres and the wheels to hold them, insulation, mass damping, more glass, more gadgets - and for every bit of mass added, everything else in the structure has to be beefed up to carry the extra mass, adding even more.

To deal with the increased demand on the engine for more power and better economy, it has had to deal with ever tighter emission controls (catalytic converter, more mass) and lower octane rating (unless you go to high octane unleaded). The main tools in managing this have been improved streamlining - and in the last twenty years the average car has reduced its Cx from over 4 to around 3.1, almost as good as Citroen had 53 years ago, and improved engine efficiency, mainly by using boost, mixture and ignition as close to preignition as possible, all computer controlled. Also helps that the efficiency of automatic transmissions has been improved.

Given the constraints, it is surprising that the improvement has been as great as it has been - most of the technical advances have gone into meeting demands for better performance with heavier cars and more parasitic power use.

John

PS that chinese crash test is nasty... them be broken legs me think.

In my short 9 years working in trauma hospitals around australia I find it amazing how many MVA are so surviveable with little trauma nowadays, mostly thanks to vehicle safety I imagine. Pretty much, MBA are the only serious road trauma creators up this way... I guess however a hospital by its very nature is self selecting for surviveable accidents... the non surviveable accidents are not presented.

s

Originally Posted by roverrescue

good points indeed Captn Rightfoot... as a town car that rarely hits 80km/h i think the rolla will do just okay for now... We will just make sure to only collide with Audi A3s' that will crumple for the two vehicles
s

Actually mate god forbid if you do have an accident you better hope that you hit an old and soft car not a new strong one. You might want to watch the video below. With the marketplace penetration of newer safer cars you can buy safety for cheap these days...

YouTube - Crash Test Betwen old and new cars.mpg

Originally Posted by roverrescue

PS that chinese crash test is nasty... them be broken legs me think.

In my short 9 years working in trauma hospitals around australia I find it amazing how many MVA are so surviveable with little trauma nowadays, mostly thanks to vehicle safety I imagine. Pretty much, MBA are the only serious road trauma creators up this way... I guess however a hospital by its very nature is self selecting for surviveable accidents... the non surviveable accidents are not presented.

s

The general public has no idea whatsoever of the dramatic improvement that has occurred in car safety in the last 15 years or so. Cars really are much safer and stronger than ever before. The authorities pat themselves on the back about moderate road tolls and sprout "more cameras more cameras" but it's the car manufacturers that are the unsung hero's that have stopped the road toll rising in proportion with population growth.

Now I promise... enough of the hi-jacking. Just one last video. It's a 81 commodore hitting a barrier at 100kph. It probably isn't of much value to this discussion but it is fun.

YouTube - Old school Commodore crashing

Ouch with the VW!

YouTube - Vw Bus Crash Test

Originally Posted by Captain_Rightfoot

..... The authorities pat themselves on the back about moderate road tolls and sprout "more cameras more cameras" but it's the car manufacturers that are the unsung hero's that have stopped the road toll rising in proportion with population growth.
.........

Unfortunately for that theory, the statistics do not support it. As far as I can find out, level of safety features in cars has little if any correlation with either the accident or the injury/death rate for that car. In fact, despite the demonisation of them, four wheel drives with antiquated design and minimal safety features have lower rates of accidents and injury/death than those cars with advanced safety features. There is a better correlation with colour!

While the design features you mention are certainly important, they only come into play when you have an accident. And the accident rate as well as the death and injury rate have come down (in absolute terms - NSW had less road deaths last year than any time since WW2 - but much more dramatically when measured against the number of cars or the number of kilometres).

In my view the improvement is largely due to better roads (believe it or not!) and very gradually, an improvement in attitude to driving - mainly the attitude to drinking and driving. Consider this fact - random breath tests show less than 1% of drivers are over the limit, but 30% of drivers involved in fatal accidents are. This has changed from just over 1% and 50% in the time since random tests were introduced. But this strongly suggests that around 1% of drivers are responsible for 30% of fatal accidents - overwhelming any effect of the safety of the cars they are driving!

As far as roads go, I just have to look at the roads I drive on regularly. Although on the face of it they have not changed, almost all still being two lane sealed or unsealed roads. But over the last fifteen years, a lot of the unsealed ones have been sealed, many of the the ones already sealed have had centre lines marked, resealed with wider and smoother surfaces, a lot of curves improved, a lot of roads with fog lines added, bridges widened (e.g. Mitchell Hwy west of Molong), this sort of thing. Not dramatic, but adding up to a steady, gradual improvement. Even in the eight years I have been using the Lachlan valley way from Molong to Yass, it has vastly improved, although on papaer it looks the same.


John

-sorry about this great big hijack all-

first captn rightfoot... some great vids there. In real world how realistsic is a 1/4 head on, both vehicles 56km/h NO braking applied??? If it happens though I guess you want to be in a 5 star!!!! ALso that commie video and VW remind me of footage I saw of a F4E phantom hitting a concrete and steel barrier at mach1... ashes to ashes dust to dust.

Ans in reply to John... I have no figures, just in my experience. 10 years ago someone has a mid speed MVA (60-80km/h zone crash) of varying type, into other vehicle, single vehicle roll/slide collide they were in a world of hurt with major leg and pelvis injuries. So from ED its up to theatre for a bilateral femoral nail and pelvis fixation followed by months of rehab... these days maybe a bit of sternal pain from the seat belt????

As I said though I dont get to see the fatal accidents... but it seems the level of trauma has markedly reduced. The impression i get is a big jump from fatal MVA to essentially walk away... where as 5-10 years ago we saw a great continuum of trauma in more cases????

S

Originally Posted by roverrescue

-sorry about this great big hijack all-

first captn rightfoot... some great vids there. In real world how realistsic is a 1/4 head on, both vehicles 56km/h NO braking applied??? If it happens though I guess you want to be in a 5 star!!!! ALso that commie video and VW remind me of footage I saw of a F4E phantom hitting a concrete and steel barrier at mach1... ashes to ashes dust to dust.

Ans in reply to John... I have no figures, just in my experience. 10 years ago someone has a mid speed MVA (60-80km/h zone crash) of varying type, into other vehicle, single vehicle roll/slide collide they were in a world of hurt with major leg and pelvis injuries. So from ED its up to theatre for a bilateral femoral nail and pelvis fixation followed by months of rehab... these days maybe a bit of sternal pain from the seat belt????

As I said though I dont get to see the fatal accidents... but it seems the level of trauma has markedly reduced. The impression i get is a big jump from fatal MVA to essentially walk away... where as 5-10 years ago we saw a great continuum of trauma in more cases????

S

I think you well may be right - given that an accident happens, modern vehicle design greatly reduces the injuries suffered, until the accident is so severe as to be unsurvivable (and there may be a larger proportion of these, since even entry level cars these days have performance that twenty years ago was the domain of a few high performance cars), but this effect is masked by the reduction in accidents, for the reasons I mentioned.

Another possible reason for fewer injury accidents may be the fact that in the major metropolitan areas, where most of the driving is done and at the times when most of it is done, speeds have become so low that you really have to try to get hurt, particularly if you are wearing a seat belt, even if you do have an accident. I know I read recently that in the previous ten years, speeds in Melbourne peak hours had halved, and I doubt the picture is very different in any major city.

John