Energy Wasted By Average Driver

Actually you do sound just like him, kind of a "Leave the oil dopes alone!" message.

Ah....all the reasons people buy a Prius, including you <grin>.

 

Hardly, Prox. I got the C because it got better mpgs than the CRX. The wife got her Prius for the free pocket protector and calculator belt clip.

I'm just saying there is more than one view point. People have differing priorities, and not always as we would have it. I'd enjoy sitting down with you for homebrew, but we'd have to leave the guns/knives at the door I think.

 

Another way to save energy is by just reducing your miles, avoid fruitless shopping errands (phone ahead to verify stock), consolidate trips. Favour local recreation spots over something across town.

 

Names of the Dead Published: August 3, 2012 The Department of Defense has identified 2,053 American service members who have died as a part of the Afghan war and related operations. It confirmed the deaths of the following Americans recently: DUARTE, Curtis J., 22, Lance Cpl., Marines; Covina, Calif.; First Marine Division. McCLAIN, Kyle B., 25, Specialist, Army; Rochester Hills, Mich.; 1433rd Engineer Company, 507th Engineer Battalion, 177th Military Police Brigade.

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Or buy Prius and don't need the imported oil and don't require 100,000 US soldiers death and injury to fuel bad choices. Flooring that lifted Silverado with the "Support our troops" bumper sticker from light to light costs a lot of troops their lives.​

 

Whatever you say to the boys at the Tea Party is OK with me, as long as you buy cars with super high mileage to cut oil use and resulting wars and pollution and push high energy efficiency technology. It's not if cat is black or white, only care if it uses less imported oil.

 

RE running lights. OK, it was intended to be humorous, but unfortunately all too many people don't get the joke.
If braking wastes fuel, then pushing the yellow is "obviously" more efficient than stopping. That seems to be a common belief - at least for whatever reason, all too many people run red lights. (I spent over a year in bed because of one - so it's a pet peeve of mine.)

 

Somehow, this discussion has drifted from reality. If you jack rabbit start, then slam on your brakes at lights, you will use a little more gas. Plugging into the equation I gave lets you know its only a few pennies a light for most people. Get all pious abut that and you lose your audience. IIRC autoweek compared two drivers and the one lifting his foot off the gas early and braking slowly saved about 15% on the city section, but that's only the city section. If someone is burning through lots of cash because of lights, there probably lots more they are doing wrong. Don't peg it all on one techique. There are lots of things to save gas. If braking is the major problem, then changing cars to a hybrid is likely the biggest thing they could do to improve. Even the mild hybrids may help.

 

A little compromise goes a long way. As you stated earlier. KE=0.5MV^, so coasting from one's high traffic speed to 70.7% of that speed gets you 1/2 of the KE energy back without acting like a complete passive aggressive rolling roadblock.

Coasting from 40 mph down to 28 mph before braking is one example of that.

 

See: Ch A Page 254: Sustainable Energy - without the hot air | David MacKay

Power into brakes = 1/ Efficiency * (1/2 * Mass(car) * velocity^3) / Distance between stops.

 

It is velocity squared for energy. You are giving a formula for power = Energy/time, but that has a number of poor assumptions that you do not need to make simply for energy. Wasted energy has nothing to do with the distance between lights. Gas efficiency does depend on the bsfc of the car, and the rate that you accelerate. In many cars feathering the gas often gives poor efficiency, as does flooring the car, but the main wasted energy only has to do with how fast the car is going when braking starts.

 

Deleted duplicate

 

Edit: Deleted comment.
AG fixed his typo so there is no point in picking on him AG said what I was going to say except better

 

Aside from the 'waste' of the speedy driver, my issue is with the idler. Yesterday I'm in Ace Hardware. Dude pulls up with his sporty V8 - and the passenger gets out to go shop. Mr spoty car driver dude stays behind ... AC going fast and furious (it was 90 here yesterday). It took me about 20 minutes to get my stuff & have a couple keys made, plus shop next door. Dude was still there in idle ... when I got out. When cars aren't used for portable AC's - that's when gas will be priced right. Jeez - Ace Hardware was a comfortable 75 or so, when I was in there. Why folks can't get OUT of the car, I'll never know.

.

 

<ahem>

Google is your friend. There are physics pages that calculate kinetic energy and give precise numbers. You may have to use other Google indexed sites to convert units into Watts or Watt hours.

Household appliances have a label showing the Watts or Volts and Amps. Watts are Volts times Amps. You might even consider converting poor driving habits into dollars and cents. But being married to a lead-footed woman for a long, long time, I know physics is one of the least effective approaches.

Over the years, I've run a few experiments:

• "Baby, I'm starting to get a little car sick. Can you drive a little more careful?" with a 'bout to throw up face. - Seems to work but has limited utility. You may need to dose yourself with Ipecac at least once and toss your cookies to improve effectiveness.
• "Oh, watch out for those new, tubular traffic rods. They are filled with paint." - and she slowed down. Sad to say, she mentioned it at a party and learned the truth of it. You may need to 'prepare' one with a washable paint and 'hit one' someday.

In reality, my wife seems to take pride in being late to every appointment. It is the only consistent hypothesis. As for appointments I schedule, it ensures we'll be late if we make it at all. So I tend to report appointment times an hour earlier than the actual time but this does nothing about 'race to the grave' driving habits.

My wife's driving habits are not persuaded by physics, economics, or social norms. They are slightly moderated by police cars that are in sight. But she treats speed limits as the minimum; traffic lights as a casino slot machine, and; anyone passing as a race. It is one reason I prefer fuel efficiency built-in to the vehicle.

Bob Wilson

 

Bob, does your wife also stay on the throttle until the last possible second before making a hard stop at each stop sign like mine does?

How many years did it take you to figure out you weren't going to win that battle with acceptable loses? It took me quite a while.

 

How about drive in windows? How much fuel is wasted waiting in line for junk food, or to make a deposit at the bank?

Just park, and walk inside!

Icarus

(not to mention emissions that provide no benefit in the net!)

I

 

Yeah, I see this every work day, people driving like crazy. They floor it, then hit the brakes - all in a hurry to get where they need to be. They could learn to take it easy, save some gas, where and tear on the car and themselves.

Wishful thinking on my behalf.

On the issue of wasting energy (slightly off topic) - just think of the energy wasted to produce ethanol.

How much energy would we save by getting rid of "lead footed drivers" and the ethanol issue?

Hmmmm, has me woundering.

DBCassidy

 

Diesel fuel used to plow the fields to plant corn for ethanol use, fuel needed to harvest the corn. The energy needed to convert the corn into ethanol use. Compounding the issues is the subsidies (read taxpayers' dollars) granted to produce ethanol. archer Daniels midland (ADM) is a large political player in this area.

Ethanol is not as clean as the supporters make it out to be. Also with the lack of rain in the corn belt, why not eliminate corn for ethanol and use it to feed livestock.

If you explore the ethanol issues (via internet, Business Week, Forbes Magazine to name a few), Yuo can begin to see what a ripoff this is to the American taxpayer.

DBCassidy