Back to 55?

[Bet51987]

I ran a little test using my dads 2008 Acura to see what the mpg difference would be at high and low speeds. Unfortunately it wasn't a fair test since I compared two different drivers so I would like to get input from other people, or some good links on what kind of benefits could be obtained from lower speeds.

He's a left lane 75-80 mph driver while I'm a right lane 55-60 mph driver. I don't speed so I couldn't do the test myself. I wasn't interested in trying the test between 40 and 55 because the energy loss has to be more pronounced at higher speeds so I needed dad and his driving habits.

Anyway, When dad drove it, he averaged 17 mpg going through three tanks but When I drove it, I averaged 26 mpg. He even had more highway driving than I did.

I believe (so far) that the highway speeds should be reduced to 55 mph like they once were. I also wanted to trade both cars in for 4 cyl models but he convinced me that what we would save in gas would never offset the cost of the new cars. (I drive a 2007 Honda Pilot which is awful on gas).

Bee

[Krom]

I always drove between 55-60 on highways, even before gas was $4/gal. Not only is it more efficient, it is safer too.

[Spooky]

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[Kyouryuu]

There's no question that going 55-60 saves an enormous amount of fuel and improves mileage. In a similar test, I was startled at the difference.

I'd rather we not change the speed limit though, mainly because I think the oil bubble is bound to pop eventually. Hopefully all of that sweet crude will land on the faces of a bunch of moronic commodities traders.

[Kiran]

I agree with that slowing down saves money. I discovered that a few months ago when the I-40 shutdown started and I had to figure out some other way to get home quicker without getting stranded at the bypass interstate.
Speed limit is 55 on this side of the interstate and I typically go between 65 and 75 depends on what the flow of trafffic is at the time. I discovered that I wasn't going to the gas station as much when I drove the main highways home going 50 mph. That's cool.

Spooky, I know that around here, if the majority of the traffic is exceeding 20-25 mph over the limit, they typically don't try to pull someone over (In reality, it's unfair to pick someone in a crowd of violators and ticket that one driver for violating and let everyone else get away). Usually they just get in their squad cars, get on the road, and have their lights flashing warning everyone to slow down.

What I absolutely hate is everyone speeding past you and then suddenly slamming their breaks when they see a cop. That sends me off on a string of cursings.

[CDN_Merlin]

Cops here won't ticket you unless you go over 20KPHof the speed limit unless you are in a school zone. If you are caught doing 50 KPH over the limit in ANY zone, your car is towed away, you get 10 demerit points and are suspended from driving for 7 days or so. This is our new street racing law they past last year ot so.

[BUBBALOU]

For what it is worth . . . babble babble babble - tax incentives for suv owners babble babble babble

How long have you been a retired oil lobbyist?

[Foil]

Absolutely agreed that driving at 50-60 has vastly improved mileage over driving faster. (For a standard combustion engine, that is... it's a bit different for electric and/or hybrid vehicles.) The difference isn't surprising when you consider the physics, but it certainly makes a big difference in terms of $$.

I also agree that people out there who drive like maniacs are just being morons. I'll admit that I drive a bit over the speed limit (especially if I'm running late for work), but when people are blowing by at 90mph where most of the traffic is driving 65, there's something wrong. [Note: if you're on a highway where traffic is flowing at 75-80mph, and you're driving 50, you're not being safe, you're actually endangering yourself and others. My father does this sometimes, and he's been cited more than once for it.]

Honestly, I really don't have any good reasons for opposing a return to lower speed limits. It would significantly improve on fuel economy, and accidents would be less deadly (yes, there would still be crazies, but the relative speed of impacts has a lot to do with rates of injury and death). The one reason I have for resisting is completely selfish: it would turn my drive between Denver and Oklahoma City from 11 hours (which is long, but I've driven it many times) to about 14 (bordering on too much).

[Testiculese]

On the highway, I set cruise at 2200 rpm, which ends up about 64mph. On the back roads, I drive at 1500 rpm or less (40mph or less).

I get about 400 miles to a tank. If I keep it above half full I get 450.

[Tunnelcat]

Although it's not realistic, I've found that 45 miles per hour is pretty much the most efficient speed for the greatest mileage, when you factor in the frontal surface area of most vehicles, the power needed to overcome air resistance and the engine's most efficient power range, given level ground and no wind. Of course this varies depending on how much frontal surface area your car or truck has. Air resistance seems to have more impact on mileage than weight in steady state freeway driving. As you go faster, the engine has to start overcoming the increasing resistance the car encounters as it pushes through the air. Diminishing returns at work here.

As gasoline gets more and more expensive, people may begin to self regulate their speeds on the freeway if they realize that it can save them a lot of money. I haven't seen that happening yet though. I wonder what price gasoline will have to reach before people start slowing down.

[Testiculese]

Honestly, I really don't have any good reasons for opposing a return to lower speed limits.

I do: The public doesn't want it.

It doesn't matter if it reduces fatalities in accidents (it won't..not with these SUV tanks plowing over smaller cars, and SUVs' tendency to roll even at low speeds), or if it saves gas mileage. The people who speed will speed regardless. When the highways were 55 here, everyone did 55, 65 or 80. When they raised them to 65, everyone did 55, 65, or 80.

Lowering the limit will do nothing but increase the revenue for the state.

[TIGERassault]

\"Sure, it might save a few lives, but millions of people would be late for work!\"

[Bet51987]

It seems apparent that law enforcement tickets when they feel like it. In fact the drivers of the police cars frequently exceed the limit themselves by fifteen miles or more. And, they are not on "no lights no siren emergency runs". (Who watches the watchers?)

I personally know the local state policeman who has been a friend of ours for as long as I can remember. One thing he told me long ago is that when he's parked on a ramp or a hill overlooking the highway, he isn't there just to slow people down but to look for things out of the ordinary and the "weaver" is his primary target. He didn't mind traffic going 75 or 80. However, 12 over the limit was technically his stop point.

In a recent meeting the re-institution of the national 55 mile limit was briefly discussed and quickly discarded as impractical.

But it's not impractical now...

I wonder what price gasoline will have to reach before people start slowing down.

Those that can afford the gas won't slow down because I see the BMW's with the dark windows passing me by pretty fast. The contractors drive fast too because they simply pass the gas cost to you. It only hurts people on a budget...and those people drive on the right lane with me.

Bee

[Top Wop]

On my car I can pull 30 MPG while doing 65 on the SSEi. It really depends on how the car and engine is built.

I dont support lowering the speed limit. Instead we should educate drivers. If you want to drive slow, great. Stick in the right lane. Everyone else use the left lane ONLY for passing. This is how its done in Europe and it should be done here. Well, it IS here, but its not enforced. Driver education in this country sucks.

Also, lowering speeds will not reduce accidents. Accidents happen at any speed. Drivers who dont know the rules or create problems cause accidents, irregardless of speed. See Autobahn.

If you want to drive slow to save gas, great! Sometimes I want to, and do, drive slow. So I stay in the right lane. If I need to go faster lawfully for whatever reason thats none of your business, then let me do so.

[Krom]

Idiots that drive fast in the slow lane and are constantly changing lanes to pass people are far more likely to slip up and cause an accident than people that drive at the same speed but remain in whatever lane they end up in for as long as it is clear.

Slow traffic keep right == fast traffic keep left. Don't change lanes without a good reason.

[Foil]

Also, lowering speeds will not reduce accidents.

Lowering speeds may not reduce the number of accidents (do you have any statistics on that?).

However, from simple physics, it does reduce the force of impacts, which is a very significant factor in deaths and injuries.

(That said, I agree with you that driver education and driving behavior are the major factors.)

[grizz]

80% of my driving is on a winding mountain road that you can't do more than 40 mph on, so it's kind of a mute point for me.

[Top Wop]

Foil: Like I said, see Autobahn. Or this:
http://www.ibiblio.org/rdu/sl-irrel.html

There's less chance of a slip up if everyone drives at the same speed together, or if people are properly using their lanes.

Slow traffic keep right == fast traffic keep left. Don't change lanes without a good reason.

You're exactly right.

[CUDA]

Also, lowering speeds will not reduce accidents.

Lowering speeds may not reduce the number of accidents (do you have any statistics on that?).

However, from simple physics, it does reduce the force of impacts, which is a very significant factor in deaths and injuries.

(That said, I agree with you that driver education and driving behavior are the major factors.)

I'm in the Collision industry. I Manage a Bodyshop for a mega dealership chain here in Portland. I RARELY see Vehicles from freeway accidents. most accidents happen within 2 miles of your home at speeds less that 25 MPH. while you will probably save a few $$ by lowering the freeway speeds. you probably will not see fewer collisions because of it.

P.S. Aug it historically our busiest month. it is also the month with our best weather. when its sunny people close their gaps up and gawk at the girls in the skimpy clothes. so if you want to reduce accidents there are 2 sure fire ways to do so.

1. out law cell phones while driving. I've seen more than my share of collisions because of them.
2. put any woman under 35 in a burka. it will stop the men from rubber necking and will allow them to pay attention to the road.

[Kyouryuu]

1. out law cell phones while driving. I've seen more than my share of collisions because of them.

Can't agree more. The DWC driver, or Driver With Cell, is completely unaware of what the heck is going on around them. They come speeding through stop signs, ignore traffic signals, cut off traffic and swerve about. It's like, if I'm driving along and some moron just squeezes between me and the car in front even though there was clearly no space, it's some asshat on the cell phone nine times out of ten.

[TIGERassault]

Well, reducing speeds does significantly reduce the chances of hitting an animal or drunk on the road, and the accidents related to it.
...but I'm thinking of urban/rural roads, not highways. There aren't enough wildlife or taverns by highways to make a difference.

1. out law cell phones while driving. I've seen more than my share of collisions because of them.

Strongly seconded! It was introduced in Ireland just a few years ago, and it really helped with averting accidents. Bluetooth and loudspeakers are allowed though.

[Krom]

I turn off my cell phone while I'm driving. It is for when I need to call someone else, I don't need someone calling me while I am supposed to be driving.

[Bet51987]

Boy did my thread go off on tangents... Let me join.

Phones... My car's GPS answers my phone for me in case dad calls me but I let it take messages for anyone else. I don't like talking while driving.

Lanes... Being in the right lane is not that comfortable. It often turns into an \"exit only\" lane causing me to shift over, or I'm constantly braking to let slow cars on, and the trucks are always moving into it from the center lane to let another truck pass. In other words, it's a busy lane.

The center lane is always full of trucks and other commercial vehicles that spew me full of rainwater as they go by, and the left lane is full of crazy people in BMW's who use all lanes for passing.

Oh well, this thread wasn't really about accidents. I just wanted to know how some have saved fuel by going 55 and I still say that the government should change it. My boyfriend had a good idea. He thinks fake speed cameras (cheap) should be installed along the highways so you can see them. Then install some real ones mixed in.

Bee

[Dakatsu]

I think we should just replace roads with rivers, and make people trade in their cars for row-boats. We can seperate lanes with those beed things you find in public swimming pools (athough it would make lane-changes hard to do). This would solve two problems:
1) Due to the required rowing for row boats to move, we have healthier people.
2) It would be hard to speed in a row boat.

Solved!

(This post was meant for humor purposes only, and is not mean't to be taken literally)

[TIGERassault]

I think we should just replace roads with rivers, and make people trade in their cars for row-boats. We can seperate lanes with those beed things you find in public swimming pools (athough it would make lane-changes hard to do). This would solve two problems:
1) Due to the required rowing for row boats to move, we have healthier people.
2) It would be hard to speed in a row boat.

Solved!

TO VENICE WE GO!