The Single Most Immediately Effective Thing a TreeHugger Can Do

Well, given that this is bike month, I'm not sure I'd put this as the most effective thing we can do.

I do have a tendency toward speed myself. That means that I need to constrain myself when I'm in a car. On the other hand, I can let myself go on a bike. It is all heart/lungs/legs - and generally makes me healthier and stronger.

forgot that tags get removed again:

http://www.bikemonth.com/

While this is good advice, merely changing the speed of the vehicle does not decrease or increase in a particular direction the amount of fuel consumed. The engine speed, or RPMs, should be monitored.

Also, speed limit does not always dictate the ideal driving conditions of a given road.

I agree with Jordan. Speed doesn't dictate energy consumption, RPMs do. Depending on the gear ratio of your car driving faster can actually be more efficient especially if you are behind other drivers where you can utilize their draft.

Also driving slower than others causes them to brake which wastes energy, and then speed up again to go around you which wastes energy. Causing others to slow down creates a domino effect and eventually leads to standstill which is the most energy inefficient situation a highway could have.

We should all just walk or bike anyway.

A while back I listened to a bbc radio show (available on-line now) about their bike trail program. It was interesting because it talked about the trips-per-100 that were walking and biking. I think it is worth a listen:

http://odograph.com/index.php?p=71

Later I found the Pedestrian and Bicycle Information Center and read one of their reports:

http://www.pedbikeinfo.org/

The interesting thing was that we in the US have managed to increase the number of bike rides we do, but the number of total trips has increased even faster:

"he NBWS, however, called for a doubling of the percentage of trips made by bicycling and walking. This percentage has increased from 7.9 percent to 9.5 percent. The disparity between the near doubling of actual trips and the slight percentage increase can be explained by the explosive growth in total reported trips made; from 249 billion in 1990 to 407 billion in 2001. In short, reported bicycling and walking trips have increased significantly, but the number of reported driving trips has increased at a rate that eclipses that of bicycling and walking."

That is sad and amazing. We've always been "car crazy" but more than just loving our cars, we've gone "trip crazy" to do all the little things that make up modern American life.

The rolling average effect of going steadily at aposted limit is to reduce the duration for which all collective engines in a carravan are under acceleration mode. There is typically very little 5th gear driving time left anymore due to the excess number of cars on the road a rush hour -- anda arush hour lasts darn near all day some places.

FYI: this post was aimed more at car commuters, not bike lovers, who are already way past that mindset.

John, this is a curve - and it has very little to do with posted limit. Your vehicle gets different mileage at different RPMs and in different gears - and it varies so much from vehicle to vehicle that I just can't find anything useful here other than simply to get people considering their mileage.

And I don't own a car, anyway. :)

I'm sure us bike riders would like to see more Bike Month posts.

I did one, but I haven't seen any yet on the other Energy and Environment blogs ...

per the site called "How Stuff Works",http://auto.howstuffworks.com/framed.htm?parent=question477.htm&url=http://www.fueleconomy.gov/ regarding my comment that rapid acceleration is less efficient they state: -- "Aggressive driving ...wastes gas. It can lower your gas mileage by 33 percent at highway speeds and by 5 percent around town".

The site also has a handy generic curve of speed versus mileage which clearly indicates that over 55mph (for an "average" car) mileage falls off as speed increases. This would be a steeper fall off that average for boxy fronted SUV' and trucks of course.

NYT Sunday had an article covering the history of Federal speed limit caps. The benefit of reduced speed was cited as in the 2 to 15% range overall, depending on drag and other factors.

My point stands: rapid acceleration and speeding waste fuel.

too many assumptions leading to a shaky claim, again. i can drive 5 hours in overdrive once i get out of nyc. if my car is running at a lower rpm at 55, than at 45, then it's more efficient to speed. if the caravan around me is geared similarly, then we're all better off. average RPMs are what count, not the posted speed limit.

i do wish i had a 6th gear for the interstate.

Some seem doubtful about government studies in general. If interested, check this third party research report, which strongly corroborates the speed vs mileage falloff at higher velocity: http://www.nesea.org/greencarclub/results%20of%20fuel%20economy%20exp.pdf

it's not the studies, it's the interpretation. speed limits are not set based on what speed gives the best mileage, but rather what maximum speed is considered safe.

like that study said, if your engine is working harder, then you are using more fuel. if you want to improve mileage, it would be more effective to keep your eye on the tachometer (which guages how hard your engine is working) rather than on the speedometer (which tells you how fast you are going).

Actually the most immediately effective treehugger thing you cacn do is to make your next meal a vegan one. Driving slower helps, but the meat industry is the worst polluter when you take into account water pollution/use and soil erosion. They're also very close to autos in air pollution. Search the web for vegetarian restaraunts in your city and give it a try, and if you drive there, don't speed ;]

actually, an evangelical vegan rarely persuades anyone. i would bet that box of vanilla-flavored, enriched soy milk did more harm to the land, air and water than my local organic milk that is bottled on the farm in reused glass. it's not the food you eat, it's where it comes from and how it's produced that matters.

Try driving a car with a neato real-time mpg indicator. If it's a well desigend engine, you'll often find that faster is actually more efficient. For a while I drove a Cadillac STS (car rental) and found that the car was far more efficient on the freeway at 75mph than at 55mph. And on the highway, it was more efficient at 35 than 45. Go figure. The speed limits are irrelevant.

Bikes, Seriously, Even in Los Angeles we're riding bikes,

Http://www.bikesummer.org

I would just like to point out that a Toyota Prius runs at it's most efficient at 62MPH on a flat road.

Go a little slower or faster and you're using up more energy. When you're under 40MPH, you can cruise on the electric (ICE kicking in when it needs to). This utilized the least energy possible.

So if you're driving a Prius on a 55MPH highway, I recommend going *OVER* the speed limit and humming along at 62.

Obviously, humming along at 80+MPH isn't very efficient.

Hijiki, thanks for pointing out the soy milk versus dairy issue. Yes, you're absolutely right - if it's local, and the cows aren't in little pens, it's definitely better. If you can find local, organic soy or rice milk, though... :)

i'm not just being evangelical, i'm providing information. in fact this whole blog is evangelical for the environment in general, but unlike religious evangelism, none of this is based on dogma. what i'm saying is that in order to produce milk you're still making alot of waste by-product and you're wasting alot of resources compared with growing plants. those plants will make the soil healthier, the air cleaner..the beans can be dried and stored indefinitely, then made into soymilk with a little grinding and water boiling. i think a soymilk co-op to distribute soymilk in reusable bottles would be beautiful and i'm going to write that down. if anyone else does it before me i won't be sad ;] just let me know so i can sign up. drive safely.

Like geekpdx, I have one of those cars that measures MPG, either every 5 seconds (which is cool but isn't useful) or between any two points (much more useful). After experimenting a bit I haven't found anything suggesting that the speed limit is the most efficient speed, at least in this car. I was very surprised to find that driving faster than 55 was often more efficient than driving 55...

if you want to improve gas mileage on any gasoline powered vehicle install a good vacuum guage and learn how to use it.

hey, wow, i'm really glad to see this article got so much feedback. may i throw in more "sense" and say that the best way to reduce global warming & air pollution is to burn less coal & reduce our dirty power (fossil fuel) demands.

efficiency & clean fuels are key. ENERGY STAR says that the avg. american home causes TWICE as much pollution as the avg. american car!

easy, easy, easy starting place = compact fluorescent light bulbs and other 'plug-em-in' efficiency products. the benefits are enormous to all, and save you money over the long term... anyway, that's what we sell them at our website: >> -- give us a visit some time & keep huggin'. thanks.

- chris

How do I understand a vacuum guage?
I have done a google for ‘understanding auto vacuum guages’ and cannot find anything.