I am lucky that my daily commute is conducive to this, but it is so true.

Today's automobile technology is so advanced that you barely feel the road driving well over the speed limit, and you can maintain (or have the illusion of maintaining) full control over your car at high speeds. It's seductive to drive fast (and get to your destination sooner).

But you will save gas, money, and the planet by slowing down. I used to drive with traffic, and get ok gas mileage. After deciding to adhere to the speed limit as a test, my overall mileage increased 33%! That is HUGE.

Obviously the speed limit as a number is relative to an individual car's highest efficiency. But slowing down from your usual cruising speed to under 60 MPH (US) will go a long way. You have to be disciplined to stick to this over the course of a full tank of gas.

If you want to try, just drive in the slow lane, and everyone else be damned – slow down, it’s your right to drive 50-60 and save energy.

I'm bad about speeding. But I will say for certain that during the recent $3.25 gas prices I actually slowed to just under the speed limit. I'm trying to stick with that.

I tried the whole driving the speed limit thing for a full tank of gas to see if it really made a difference. Besides the indiginity of constantly being passed from all sides, I saw no change in the fuel economy in my car. While it was highly unscientific test, I was not impressed with the results.

Needless to say, I'm back to driving over the limit, as I am now going with the flow of traffic. Unlike when I was in Chicago, going over the limit here is only 5-10, not 20+.

I own a 2004 Honda Insight CVT. If I drive the speed limit, I can achieve between 65-75mpg, if I start creeping above 60mph, It quickly drops to 50-55mpg.

Unless you have some weird gear ratios, or really great drag coefficient (but I don't think anything beats my .25), you're going to exponentially burn more fuel, the faster you drive.

Also, I simply don't see the point to speeding. Lets do some math! We'll assume we have a 30 mile commute and sustain a speed the whole time (which we all know you could never do).

30mi / 60mph = 30min
30mi / 65mph = ~27min 42sec (diff: 2min 18sec)
30mi / 70mph = ~25min 43sec (diff: 4min 17sec)
30mi / 75mph = 24min (diff: 6min)

So, you could effectively save six whole minutes of your day if you were able to sustain a speed 15mph over the limit.

Moral?

"Speeding tickets are a tax on the mathematically challenged."

What, no option for those of us who drive under the speed limit?

I only speed when I'm trying to catch the next light. Stopping at the light, idling the car, and accelerating back to speed is a waste of gas, even in a hybrid. So race those yellow lights folks!

How about the option of:

When driving on fossil fuel I obey the speed limit at all times. When driving on waste vegetable oil I drive like a bat out of hell!

Oh, and don't make other people suffer by driving below the speed limit and clogging up the road. That is simply selfish and reckless, as you will cause people to try anything to pass you. Drive at or 5mph above the speed limit. Unless you're a sociopathic wacko.

Turil et al-

If you're in a one lane road, do the speed limit. It will eliminate others trying to go around you with oncoming traffic in the other lane.

On highways with speed limits of 55 or higher, it is dangerous NOT to do the limit, as others who are going 55 or higher have to get around you, sometimes in sketchy situations. And this also creates road rage (not putting the blame on slower drivers; ragers have their issues).

I live in Colorado where a law was passed which states that on multi lane roads with speed limits of 65 or higher, the left lane is for passing only unless there is significant traffic.

I second (third?) the call for an "I drive below the speed limit" option - a glaring omission in a poll asking about eco-driving.

Before I get jumped on, I'll add that I only do so when it's safe and practical based on road and traffic conditions.

To argue that everyone must always drive the speed limit in the name of safety is generalization that ignores the fact we don't all live in areas of high traffic density (I don't).

Plus, it's an outlook that fails to recognize peoples' ability to figure out independently when it's safe to do so, and when it's better to go with the flow.

I can't help not driving the speed limit. I have the need for speed and i can't stop. By speeding gas mileage for my car is affected so minimally that it is not worth going slow. I would rather go fast and have fun instead of going slow and getting a minimal increase in gas mileage.