Will the 55 mph speed limit be reintroduced?

[bamx2]

I wouldn't mind it but first try enforcing the existing speed laws . Around here (FL, GA) , 10-20 mph of the posted speed is the norm . If you run at the post speed limit , it is almost dangerous .

 

[CycloWizard]

Originally posted by: charrison
If you want to continue to compare a statistical generalization based on fleet data to a single car, you can continue to make yourself look like an idiot. This generalized statement was made by a fuel economy engineer at GM and he probably knows quite a bit more on the subject than the entire population of this forum.

And yes I did understand all the finer points you are were trying to convey. However, I can find nod no data that supports any of you claims. I have no problem finding studies saying going slower saves fuel as there are quite a few of these. The only thing close i can find is a 97 toyota celica that get about 2% at 65 than 55, everything seems to do better at lower speeds. However I cant find any real reference to anything that does better at 70, much less 90, other than anecdotal stories like yours.

But as stated it was a rule of thumb not an abosolute law. so give on trying to make it sound like i was making it to be an absolute.
Still waiting for any data stronger than anecdotal for you to prove your point.

At this point, your very literacy is in question, let alone your understanding of the problem. You claim to understand the "finer points," yet you continue to argue against them. In any case, my parents are in town due to my getting hooded tomorrow, so I'll digress and leave you to your appeal to authority.

 

[charrison]

Originally posted by: CycloWizard

At this point, your very literacy is in question, let alone your understanding of the problem. You claim to understand the "finer points," yet you continue to argue against them. In any case, my parents are in town due to my getting hooded tomorrow, so I'll digress and leave you to your appeal to authority.

As I stated I have yet to see any evidence(other than anecdotal) of any car getting better fuel economy at 70 or 90. If you have some published data on this, let me know. Otherwise I have to rely on the tons of published data that says peak fuel economy happens around 40-50mph.

While you call this an appeal to authority, I think it more accurately called an appeal to facts and reality.

Congrats on getting your phd. Just remember in order to get to that level of education you have to learn more and more. about less and less, and pretty soon you know nothing at all.

And as far as my literacy goes, my education is not far from yours. With you education level you should well know there is large difference between saying something is true and proving something is true.

 

[CycloWizard]

Originally posted by: charrison
As I stated I have yet to see any evidence(other than anecdotal) of any car getting better fuel economy at 70 or 90. If you have some published data on this, let me know. Otherwise I have to rely on the tons of published data that says peak fuel economy happens around 40-50mph.

While you call this an appeal to authority, I think it more accurately called an appeal to facts and reality.

You haven't shown any data either, chief.

Congrats on getting your phd. Just remember in order to get to that level of education you have to learn more and more. about less and less, and pretty soon you know nothing at all.

Unfortunately, apparently everything I've learned about fluid mechanics over the last nine years was a lie. Fortunately, I fooled some people at some pretty nice schools into thinking I knew something - enough to get a job anyway.

And as far as my literacy goes, my education is not far from yours. With you education level you should well know there is large difference between saying something is true and proving something is true.

I've never made any claims in this thread (except the specific one regarding my own car, which I have extensive data to support). I've simply pointed out that your claims are incorrect by invoking physics. Bottom line: saying that one can improve one's gas mileage by slowing down doesn't make good physical sense. In some cases, it will be correct, but other cases (which are numerous), it is incorrect.

 

[charrison]

Originally posted by: CycloWizard

Originally posted by: charrison
As I stated I have yet to see any evidence(other than anecdotal) of any car getting better fuel economy at 70 or 90. If you have some published data on this, let me know. Otherwise I have to rely on the tons of published data that says peak fuel economy happens around 40-50mph.

While you call this an appeal to authority, I think it more accurately called an appeal to facts and reality.

You haven't shown any data either, chief.

That is easy enough to do. I will dig them up again and post some of them.

Congrats on getting your phd. Just remember in order to get to that level of education you have to learn more and more. about less and less, and pretty soon you know nothing at all.

Unfortunately, apparently everything I've learned about fluid mechanics over the last nine years was a lie. Fortunately, I fooled some people at some pretty nice schools into thinking I knew something - enough to get a job anyway.

I never said you did not know what you are talking about and I do understand the points you are making. However, it does not invalidate the statistical data based on the current car fleet that says otherwise.

And as far as my literacy goes, my education is not far from yours. With you education level you should well know there is large difference between saying something is true and proving something is true.

I've never made any claims in this thread (except the specific one regarding my own car, which I have extensive data to support).

I give you the benefit of a doubt here, but I do remain skeptical. But I also know it is not a trivial equation either.

I've simply pointed out that your claims are incorrect by invoking physics.

Unfortunately the real world stats dont agree with your theoretical physics.

Bottom line: saying that one can improve one's gas mileage by slowing down doesn't make good physical sense. In some cases, it will be correct, but other cases (which are numerous), it is incorrect.

[/quote]
The stats currently show it is correct in the vast majority of cases. Here is quick link, but there are more if you wish.

linkage

While each vehicle reaches its optimal fuel economy at a different speed (or range of speeds), gas mileage usually decreases rapidly at speeds above 60 mph.

Estimates for the effect of speed on MPG are based on a study by West, B.H., R.N. McGill, J.W. Hodgson, S.S. Sluder, and D.E. Smith, Development and Verification of Light-Duty Modal Emissions and Fuel Consumption Values for Traffic Models, Oak Ridge National Laboratory, Oak Ridge, Tennessee, March 1999.

 

[theblackbox]

i spent two years (2004-2006) driving a hybrid 106 miles to and from work(total) 5 days a week. I found that amazingly, 55 is the best speed for fuel effeciency, at least in my civic hybrid. I tried every combination and that is what I found. Since I sold my business, house, and the hybrid, i now rv fulltime and drive an rv puling my wrangler. I get about 7-8 mpg regardless of what speed i drive but i still drive 55, because thats fast enough. i watch everyone around me drive much faster, and feel sorry for them. everyone is in too much of a hurry to enjoy life, as they rush from one place to another. personally, if they reinstate it, it wouldn't change anything. people will still hurry from one place to another, and i'll still take my time, enjoying life.