I'd call 2-3mpg average over the journey negligible, perhaps you wouldn't. The differences do vary wildly depending on the car concerned however, our micra is much more fuel efficient at 60mph than at 80mph, the S3 and the R36 not so much.
You argue 2-3mpg but there is no idea of the percentages there, and frankly I would argue there are other factors like you continue to use excessive acc/braking and hence you aren't driving efficiently enough to start with. The Audi S3 is capable of 42ish on an extra urban cycle, and I would imagine that is doable at 55-60ish MPH, although I bet it will be much closer to 30ish at 80mph if you aren't achieving those figures, then it is down to you, not the scenario.
But by saying 'all else being equal', you've specifically ignored the point I made, that not all cars are equal. That is not semantics, the difference between braking performance between different cars is significant and substantial. As such declaring one speed safer than another, ignoring all other factors, is a fallacy, specifically the fallacy of the single cause.
Of course I argue all else being equal, I am discussing the same car driven at 60 compared to 80mph? That is apples with apples, stay on the plot please.
What are you using if not your experience?
Ah, your experience and an appeal to authority, gotcha.
Ah an attempt to ridicule to make you point, yeah I was Police class 1 trained, I am doing IAM and I have 3 Police Officers in my family, sorry I can't quote them on the internet.
Nice strawman, try actually linking the points to arguments I have made. I never said that thinking times were the same (although they are, you are confused between thinking time and thinking distance), that there is no difference in economy, and I certainly never claimed that 80mph produces less accidents, just that it does not generate appreciably more.
To suppor that, we have a Department for transport report...
http://www.dft.gov.uk/pgr/statistic...asualtiesgbar/roadcasualtiesgreatbritain20071
Choose article 4, Table 4f.
Exceeding the speed limit comes under injudicious action, and comes in at 3% on the motorway. Compare that with the other causal factors of accidents to see how flawed making a road safety claim based on travelling speed is.
If you have a given distance to react in, then at 80, it requires less time, again you try arguing semantics without addressing the point. Look at the cause factors, most of them will involve some form of excessie speed for the conditions, following too close, failuure to react in time, all of these are a product of excessive speed for the conditions or following too close. I agree 100% that breaking the speed limit is rarely a cause, I have never argued that, but driving too fast for your observation and skill level is another thing entirely.
Where did I do that? All I argued was that the 60mph drivers on the route I regularly used are the sort of drivers that observational awareness (and police driver training) teaches you to avoid, and given the small gains in fuel consumption, I would rather avoid them and sacrifice that tiny gain in fuel economy for not being around poor, visibly inattentive drivers. Everything else has been in response to your attempts to justify why driving slower is better, safer etc based on incomplete arguments or fallacies. Just because a fallacy is often repeated or promoted by the government does not make it any less a fallacy.
And like I said all along, you're justifying your reasons for not doing 60, and that is fine, as your skill is clearly good enough as you are driving a performance car and not having accidents. I am not justifying anything, all along I have said that driving economically is a skill and involves optimising your speed as well as your use of the various controls carefully.
The fact is, at 60, you require a given BHP to travel at that speed, at 80, you require significantly more BHP to travel at that speed, that will mean an increase in fuel consumed. THESE ARE FACTS, IF you want to decrease your fuel consumtion,(which clearly you don't) then a change of driving style is required. That may not sit with you, but it is a fact that is backed up by years and years of data on fuel consumption.
So in summary, driving at 60 is no less safe than at 80, the point you tried to argue in your original post, and fuel consumption will improve if you drive slower and more efiiciently. I really don't see any evidence in any of your posts to dispute this as anything but fact. All you have managed to prove is that your car may not be significantly better on fuel at that speed and that you don't see the point.
So if you want to provide evidence, provide evidence that 60 is less safe than 80 and that a car can be more fuel efficient at 80 than 60, otherwise you are arguing for the sake of arguing.
