Posted on 05/01/2005 6:19:00 AM PDT by MississippiMasterpiece
President Bush made it clear last week that he sees no quick fixes to the nation's energy woes. The problem has been long in coming, the argument goes, and so will the solutions. But if history is any guide, there is one thing he could do immediately: bring back the 55 miles-per-hour speed limit.
It has been done before. Along with record oil and gasoline prices, improvements in fuel efficiency and a lasting economic recession, speed limits helped curb fuel consumption for the first time in American postwar history between 1974 and 1984.
Of course, energy eventually became cheap again, the economy expanded and Americans became complacent and unwilling to make more sacrifices.
Instead of opting for small fuel-efficient cars, people switched to large sport utility vehicles and larger pickups. As drivers groaned and states fought for their right to speed, the limit was raised.
While oil consumption in most industrialized nations has either leveled off or declined, in the United States, oil demand has soared 38 percent since the first oil shock of 1973.
The Bush administration's focus over the last four years has been to increase the supply of oil and natural gas, which are also priorities for the energy industry, instead of finding ways to cut back on energy demand, which until very recently has been left out of the picture.
"We are in a boxing match, and the president keeps one hand tied to his back," said Steven Nadel, the executive director for the American Council for an Energy-Efficient Economy, a nonprofit research group in Washington. "We're punching with supplies and not using demand. We're at a disadvantage."
Other industrialized countries, especially in Europe, have been much more successful than the United States and have managed to actually lower oil demand, or at least keep it in check. That comes from higher diesel use and higher taxes. In France and Germany, a gallon of gasoline sells for as much as $6, with taxes accounting for about 80 percent of that.
Few politicians in America might risk ridicule or rejection by explicitly supporting higher taxes on gasoline, one of the surest ways to limit the nation's dependence on oil.
"Even the least outrageous gasoline tax would have choked off some demand, and the money would have gone to our own government instead of being transferred overseas," said Robert K. Kaufmann, a professor of geography at the Center for Energy and Environmental Studies at Boston University. "Of course, that would have to involve personal sacrifice, which is off the table politically."
There are other ways to curb consumption that may be only slightly less challenging, analysts say. One would be to increase the average mileage per gallon requirement. After Congress passed legislation forcing automakers to act in 1975, average mileage almost doubled to 27.5 miles a gallon in 1987 from 14 in 1972. But it has since slipped back to 24 because of S.U.V.'s, and Congress shows no inclination to toughen the standards.
Another way to sharply reduce demand - and improve mileage - would be to encourage drivers to buy diesel cars, which offer as much as 60 percent more fuel efficiency, said Theodore R. Eck, an energy consultant and former chief economist at the Amoco oil company.
"The neat thing here is that this is off-the-shelf technology," he said. But the trade-off to diesel fuels also includes higher emissions of nitrate oxide, a pollutant that is responsible for smog.
In a recent speech, President Bush suggested that diesel cars might be made eligible for similar income tax credits as hybrid cars, which are quickly turning into best sellers with long waiting lists.
The present predicament behind high oil prices is quite different than the oil shocks of the 1970's and 1980's, which were a result of producers in the Organization of Petroleum Exporting Countries cutting oil supplies. Today, the price shock comes from rapidly increasing demand, driven largely by China, but also by the United States and its strong car culture.
After rising 33 percent in the last year, crude oil prices in New York slipped below $50 a barrel on Friday for the first time in 10 weeks. They closed down nearly 4 percent at $49.72 a barrel.
Still, Americans can expect to pay record prices for gasoline this summer. According to the latest national average compiled by the Energy Department, gasoline prices at the pump averaged $2.24 a gallon, up 42 cents from last year; they are expected to touch a record $2.35 a gallon this summer.
Polls show that higher gasoline prices are increasingly hurting Americans, and the president is pressing Congress to revive an energy bill that has been stalled for four years.
Since the last energy shock of the 1980's, the economy as a whole has shifted toward services and away from heavy industry and is now less dependent on oil than it once was. But that has been more than offset by the rise of oil demand for the transportation sector, which accounts for two of every three barrels of crude oil consumed here; gasoline alone amounts to half the nation's oil consumption.
"We've had this situation building up for years, and yet the focus continues to be on the very long term," said Shirley Neff, an adjunct professor at Columbia University and a former economist on the Senate Energy Committee. "We have to focus on demand and be more efficient in our energy use. We need something like an Apollo program for the transportation sector."
But restricting demand might also weaken economic growth, an unpalatable prospect for any government, especially at a time when some are already blaming energy costs for a slowdown in growth.
"It's true that there is a limit to what you could achieve through a traditional energy policy in one or two years," said Fridtjof Unander, an analyst with the International Energy Agency, which advises industrialized nations on ways to reduce their consumption.
The 55 miles-per-hour speed limit came as a result of the 1973 Arab oil embargo. The Nixon administration ordered states to lower their maximum limit to save fuel at a time when the first oil shock threatened to bring the economy to a standstill.
After steadily rising each year, gasoline demand suddenly stopped growing in 1974 and remained nearly flat for the next decade, keeping oil consumption in check.
Roland Hwang, the vehicles policy director at the Natural Resources Defense Council in San Francisco, estimated the savings of the speed limit in 1983 at 2.5 billion gallons of gasoline and diesel fuel, or 2.2 percent of the total use for these types of fuels.
But as gas lines faded from people's memories and energy prices went down, the federal speed limit was relaxed in 1987, allowing states to set higher caps of 65 miles an hour. Once more, gasoline consumption surged.
Smaller efforts today could make a difference. For example, driving at 10 miles an hour above the 65 miles-per-hour limit increases fuel consumption by 15 percent; inflating tires properly cuts gasoline use by 2 percent; keeping engines idle while in line wastes millions of gallons.
The trouble is that few drivers bother with these suggestions, Mr. Hwang said. "People are basically too lazy to pump their tires up."
To push a vehicle at low speeds where rolling resistance predominates, the force required is proportional to speed. More speed -> more force for the given distance --> more work/mile. Have you ever pushed a vehicle any distance? Tried to push it faster? I believe that you will find it takes more force to push it faster.
The required power to meet the rolling force needs is a constant * V^2. Aero force is a constant*A*Cd*density*V^2. Aero power is proportional to V^3. So total required road load horsepower is rolling constant * V^2 + Aero constant * V^3.
Work done/mi = power * Time. That divides the velocity out for a given mile getting back to work done = ~ (rolling resistance force + Aero force)* distance.
So one measures the coast down time. The vehicle mass (ignoring the energy in rotation of wheels/tires/brakes/driveline (you do do the coastdown in neutral? right?) times V^2 gives the energy at the starting speed and the ending speed. The difference gives you the energy expended. Divide by the time and you get average horsepower over that time. Multiply the required horsepower times the expected engine BSFC (at the appropriate engine speed and torque) * gal/lb (~1/6.15 for gasoline) * driveline efficiency gives you gallons/hr. Take mph and divide by the above and you should have an estimate of mi/gal.
I've owned a diesel in one form or another since 1985. I love 'em.
Recently purchased a 2005 VW Passat Wagon diesel. Rates 28 city and 38 hwy. It's a cruiser!
Unfortunately, it only came with automatic. First time I've owned an auto in almost 30 years. Still trying to get used to it.
We just bought a Jetta TDI 5-speed manual station wagon. The fat torque curve from ~1500 to 2500 gives the equivalent horsepower of a ~3.2L gas engine at those engine sppeds. So in the cut and thrust of every day driving, one gets decent performance without having to downshift and respectable FE. Diesels don't typically wind out so the 0-60 times are a little slow, but to accelerate into the space when changing lanes is a piece of cake. Now I only have to buy fuel (14 gal vs 22) every other week instead of once a week.
From your lips to God's ears. I have a 2001 Corvette that gets 32 mpg @60 mph in 6th gear. It also does 0-60 in 4.7 seconds when I'm feeling frisky.
Manual Trans C4? 'Vette's are the poster child for performance and economy. There's no reason a Suburban shouldn't be able to do at least 25 mpg at 60mph. Looks like I have to (re)build my own.
I thought about buying one of those, but I'm leaning towards the Jeep Liberty CRD, as I live in the mountains, and could use the 4WD. Too bad VW doesn't offer the Passat TDI with 4MOTION.
C5, 6 speed manual tran. @ 60 mph in 6th gear it does a rumbling 1200 rpm.
Yep.
For one, you'd have to pay truckers that extra day it takes to get a shipment in.
I was going to get a 6-spd Wrangler unlimited, and then stumbled across the TDIs. The Jettas don't have much ground clearance, so for the deep stuff I'll have to get the '90 'burb ready for this winter.
I was looking at getting a CRD but the mileage just wasn't there for me. Couldn't justify it otherwise. Nice vehicle though!
I had a 2004 Jetta Wagon TDI. 5-spd too. My wife flipped it.
She's OK. Not a scratch. Car was totaled though. I loved that car. And I averaged 40mpg in it; 36mpg going thru the VA mountains going 80mph loaded with bikes and gear :-)
Think about it. If inflation was the only factor to the equation that formula would work, but its not. I personally had my wages frozen for 3 years and then cut by $2.00 per hour in the forth. Non of this is factored in.
I'm comparing to my own wages.
I have a feeling that the EPA estimates run low on diesels. What is your Passat giving you in real-world driving?
Or in cities like Boston where the local hacks have no turn on red signs up at just about every intersection.
that's always been the east coast solution and contempt for the western states that drive longer distances.
I drive an SUV and pay 30-50 dollars a week on gas depending on how much i drive. I dont think what I'm paying right now is all that egregious even on what I'm making on a college student's wage. I have noticed that the primary poeple b*tching about gas prices drive little hondas and pay 20 bucks a week if that on gas. While spending well over 100 dollars a week on booze, smokes, and drugs.
I was trying to simplify the problem to make it easy for people to understand. Technically speaking the force of rolling resistance has two components: one is constant with velocity, the other part tends to be proportional to velocity; I ignored the second part to make the analysis easier for people to understand the effect of aero drag.
Have you ever pushed a vehicle any distance? Tried to push it faster? I believe that you will find it takes more force to push it faster.
Why, yes I have; 180 yards at a time in the low 20 second range, to be very specific about it. And I've done it enough to understand that the increase in force is required not because the rolling resistance increases by any significant amount, but because Newton says you have to add force to accelerate the mass of the vehicle to a higher velocity. And once at the higher speed. the power required remains higher at a higher speed because you are doing the same amount of work (force over distance) in a shorter period of time. P=Fv.
The fact remains that, as I said originally, to a first order approximation, the force you exert on the pushbar with your hand is essentially the same whether you're going 10 mph or 20 mph, as long as the speed is constant and the pitch of the hill is neglible. That's a fact I have empirically verified countless times. That's why the rolling resistance equation, as it applies to a particular wheel/tire setup, is usually stated in the form
You'll notice the conspicuous absence of a velocity term in the equation.
"'We need to look at what it will take to get manufacturers to offer technologies that people want.' One obvious step, which politicians are loath to even mention, would be to increase taxes on gasoline."
What a grand idea, let's increase taxes so people will 'want' to change their behavior.
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