are there any advantages to Driving Slower?

The QUESTION was if driving slower saved the machine, or just gas.

Without regard to what I feel about your speed being sufficient or not and the ramifications thereof, there is no benefit to the machine, so the only benefit is to the gas. And, the savings here is minimal.

When the speed limit was lowered to 55, it was hoped that the fuel consumption would be about 2.2% less than the then-current consumption. Studies by the Department of Transportation found the fuel savings to be closer to 1%, and an independent study found the reduction to be only about

0.5%. Contributing factors to the new consumption rates staying as high after the new speed limits as before the limits was that the 55 limit was widely ignored. (I have to assume that a return to a mandated lower speed limit would also be also be widely ignored. One can save fuel on a personal level, maybe, but on a national scale it has been found that lowering speed limits does not work to save fuel.)

It turns out there is ample discussion on whether the lower speed limit was safer, and some studies show that the lower speed limits actually raised accident rates. (Without reading the studies, my guess is that the vast majority of the population that ignored the rule ran over the minority that observed it...)

None of your feelings on your comfort, or mine, have anything to do with the topic that was raised. And to answer the question presented, while there is no mechanical advantage (in terms of saving wear and tear) there appears to be little advantage to the fuel consumption either.

right. And the assertion at hand is that "cars did not like the abuse that came from driving them too slowly". Citations?

Or else it's bullshit.

"Elmo P. Shagnasty" wrote in message news: snipped-for-privacy@news.eternal-september.org...

You made 5 false assertions that I addressed in one post. You really need to stop breaking stuff down to the individual words and making a comment about each of them separately. It confuses you when you make 5 posts in 6 minutes, and somebody replies to all of them at once.

Driving the cars at the lower end of the power band, which happens in pre-'70s cars driven at 55, causes them to operate in a range that forces frequent downshifts. That is a fact, I survived it.

This happens today on 4- and 5-speed automatic transmissions, and the cure is to downshift (move the gear selector) to the gear that the transmission selects so that the selected gear is held until the conditions that cause the shift have gone away. It is bad for one to allow the transmission to downshift then upshift then downshift again over and over while ascending a hill on the freeway. Cars built in the '60s typically had a 3-speed automatic, so the downshifting on a hill on the freeway caused high engine speeds for the vehicle speed. The issue was easily cured by increasing the vehicle speed to 65 or 70, where the engine hummed along easily and did not bog down because the confluence of low speed and highway incline created conditions where the engine had to go from operating at the bottom end of the power curve to operating at the very upper limits of the power curve. Consider that many (way more than half) of the cars on the road for the Double Nickel Speed Limit were built in the '50s and '60s where highway travel at 65 or more was the norm. Puttering along at 55 is not problematic all by itself, and I am not making an argument that it is bad. But when a car gets out on the interstate for hours on end, or where drivers live in a region where the interstate is hilly, and the drivetrain is forced to operate at the extreme lower or upper end of the power band, then this is generally accepted as a bad condition that one should seek to avoid. If I have to provide a citation that this is true, then you should stop hanging out in automotive news groups and pretending you know anything about a car.

Driving a car at the lower end of the power band so that frequent downshifts happen causes the plugs to foul. This is more true on the carbureted engines of yesteryear (which were the predominate engines on the highway in the days of the National 55 Speed Limit) than it is on today's cars with modern fuel injection equipped with sensors that constantly maintain an air/fuel ratio of 14.7:1. The double nickel was hugely problematic on many levels, most of them having to do with designing a car for a particular environment, then forcing it to operate in another environment.

Focus.

You made the assertion that "cars did n ot like the abuse that came from driving them too slowly".

Despite my asking more than once, you continue to dance around providing citations for that.

All I say is, citations or it's bullshit. If you have citations, it's not bullshit and you have no reason to be mad. Simple If you don't have citations...

But you claimed that research showed this abuse. Now you're claiming that you experienced it? That may be, but I'm still waiting for you to show the research.

You continue to dance. YOU made the claim about there having been research on this very specifically in the context of the 55mph NMSL, but now you're dancing around the matter when someone presses you for details on this research.

So now all you have left over from your assertion that "research showed that cars did not like the abuse" is "it's generally accepted that this one transmission behavior is bad".

Roaming from "abuse" in general to "this one transmission behavior" and couching it in terms of "everyone knows that, I don't need to provide citations" is your very bad effort at dancing around and trying to get out of the fact that it appears that you made specific shit up out of thin air to try to make yourself seem important.

Notice in none of that did I dispute anything you said about gear hunting, but no doubt you will ignore that and simply attack as you try to divert attention away from the fact that you made shit up out of thin air to try to make yourself seem important.

If you don't have specific citations, then don't claim to have them in the first place--or else don't get all bent out of shape when you get called out on your claims.

I don't recall claiming research. I have anacdotal information. I gave you sound reasoning to support the anacdotes. But, this has nothing to do with the topic that you have yet to address in any way other than to offer support for fuel savings THAT THE OP ALREADY ACKNOWLEDGED, and that I have told you that the government itself said did not hold up on a national basis. Saving gas by going 55 might work, but mandating 55 to save gas did not work. That is a fact.

I have nothing further to say unless you can find something that says doing

50 instead of 60 will save the car. That's the discussion here. Well, it's the discussion I was having with the OP -- who has not been back -- until you came along.

Did you completely miss my post on "comfort level"?

If grampa is comfortable at 55 in the right lane, and he's driving a modern car that isn't gear hunting (say, a Prius that *does* do SIGNIFICANTLY better at 55 than at 65), and he's happy to adjust himself to accommodate entrance ramp traffic for maximum flow--then he has a

100% valid reason for driving less than 65 in the right lane.

Or did you miss that post?

The OP seemed to understand that, and SPECIFICALLY asked if there was an advantage to the machine. THE MACHINE was the question, not the comfort of the commute.

the MACHINE is a system that includes the metal bits as well as the organic bits. In other words, the MACHINE is nothing but an inert lump of hardware without a driver behind the wheel.

And the MACHINE will last longer if the driver is in his comfort zone.

Tire wear is accelerated as is engine wear. The windshield will have more bug spatters. Accidents will be more severe and more frequent.

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There is a sweet spot (most engines ~ 2000 to 2300 rpms) in the power curve that produces the best effency and lowest engine wear. If the engin and the load are properly matched driving slower can reduce both effency and increas wear.

As to tires that is a lot more complex than just speed.

No, but if you get in a crash, you're more likely to survive, as are the passengers in your cars and other vehicles involved.