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I think the op has some valid points implied, not the fuel efficiency aspect. Some people are so slow to react to a green left arrow that only 4 cars get through when 7-8 could have made it if everyone was on the ball. So it comes down to common courtesy. With so many cars on the road we simply do not have the luxury of each car taking excessive separation distances.
I have noticed it happens a lot more now. Lots of people use the red light to read or send a text or whatever on their phone and have no idea the light has changed. Very annoying.
Peak efficiency is achieved by accelerating relatively quickly (not flooring it) up to 40-45mph or wherever your highest gear kicks in and maintaining that speed for the entire trip. Staying as close to that ideal as possible will give you your highest MPG.
"For example, a reciprocating engine achieves maximum efficiency when the intake air is unthrottled and the engine is running near its peak torque."
So WOT at ~the torque peak.
For my engine, peak torque is at 3600 rpm. It's an automatic, so a throttle opening between one that keeps the rpms around that range and WOT (which would produce higher rpm shifts) would probably be optimal.
I think any efficiency comparison should normalize for total time. Accelerating faster will reduce the cruising speed necessary to cover the same ground in the same amount of time, resulting in an additional benefit for fast acceleration.
Of course wear and tear on your engine, drivetrain, tires, and passengers will be greater with fast acceleration.
I have to question how slowly you accelerate for people to actually honk at you? I accelerate at a nice smooth pace and definitely don't try to speed up aggressively... However, I never get the honks. I wonder if you just have to deal with more psychopaths than I do or whether you really do accelerate that much slower than me.
It doesn't happen often, but occasionally I get the impatient jerk that's in a hurry. My car is not particularly fast and some people just can't wait to get to the next red light quickly enough.
Slow acceleration saves gas = stupid myth . If I fill my bathtub slowly will I save water ?
No, but you will use less energy to fill it because that is time dependant.
Power = work/time
work is always the same in your example. The time varies.
We weren't talking about "minimizing the number of people...."
You just accomplished the "double strawman" where you make up yet another scenario in order to defend the previously constructed scenario.
Because surely none of us agree with your views that we should be able to drink whatever amounts we want and still operate vehicles without consequence.
Yes the strawmen are everywhere here, don't light a match! Or, maybe we should? These folks remind me of the type of person that drives 15 miles out of their way to save $0.05 per gallon on a 15 gallon fillup at that cheap station they always rave about.
In this episode of "Stepping over Dollars to pick up Pennies" we hear how someone improved their average fuel mileage from 33 to 35mpg (or something like that) by accelerating like a slug. What did it take? - Well they only had to expend, cumulatively, an extra 30-60 minutes of driving per tank to manifest the savings. Wow, congratulations!!! You saved yourself $3 per tank and you only had to sacrifice an hour of your time. Hey, it was worth it because you know, going a little faster is guaranteed to put you in the grave.
Wow so many replies after the weekend ! I can't reply to all right now but there is this you may want to check out:
Much of the time, automobile engines operate at only a fraction of their maximal efficiency,[31] resulting in lower fuel efficiency (or what is the same thing, higher specific fuel consumption (SFC)).[32] Charts that show the SFC for every feasible combination of torque (or Brake Mean Effective Pressure) and RPM are called Brake specific fuel consumption maps. Using such a map, one can find the efficiency of the engine at various combinations of rpm, torque, etc.[25] During the pulse (acceleration) phase of pulse and glide, the efficiency is near maximal due to the high torque and much of this energy is stored as kinetic energy of the moving vehicle. This efficiently-obtained kinetic energy is then used in the glide phase to overcome rolling resistance and aerodynamic drag. In other words, going between periods of very efficient acceleration and gliding gives an overall efficiency that is usually significantly higher than just cruising at a constant speed.
Wow so many replies after the weekend ! I can't reply to all right now but there is this you may want to check out:
Much of the time, automobile engines operate at only a fraction of their maximal efficiency,[31] resulting in lower fuel efficiency (or what is the same thing, higher specific fuel consumption (SFC)).[32] Charts that show the SFC for every feasible combination of torque (or Brake Mean Effective Pressure) and RPM are called Brake specific fuel consumption maps. Using such a map, one can find the efficiency of the engine at various combinations of rpm, torque, etc.[25] During the pulse (acceleration) phase of pulse and glide, the efficiency is near maximal due to the high torque and much of this energy is stored as kinetic energy of the moving vehicle. This efficiently-obtained kinetic energy is then used in the glide phase to overcome rolling resistance and aerodynamic drag. In other words, going between periods of very efficient acceleration and gliding gives an overall efficiency that is usually significantly higher than just cruising at a constant speed.
OK great. Now leave your transmission in 2nd gear, keep your rpms at 75% of redline, and drive to work and back. Report back and your massive increase in fuel economy.
OK great. Now leave your transmission in 2nd gear, keep your rpms at 75% of redline, and drive to work and back. Report back and your massive increase in fuel economy.
What does that have to do with anything?
Max engine efficiency would be at WOT and ~75% of redline. You are missing the first part.
Yes the strawmen are everywhere here, don't light a match! Or, maybe we should? These folks remind me of the type of person that drives 15 miles out of their way to save $0.05 per gallon on a 15 gallon fillup at that cheap station they always rave about.
In this episode of "Stepping over Dollars to pick up Pennies" we hear how someone improved their average fuel mileage from 33 to 35mpg (or something like that) by accelerating like a slug. What did it take? - Well they only had to expend, cumulatively, an extra 30-60 minutes of driving per tank to manifest the savings. Wow, congratulations!!! You saved yourself $3 per tank and you only had to sacrifice an hour of your time. Hey, it was worth it because you know, going a little faster is guaranteed to put you in the grave.
In this episode of "Stepping over Dollars to pick up Pennies" we hear how someone improved their average fuel mileage from 33 to 35mph by accelerating like top fuel dragster. What did it take? Well, they ended up plowing into the guy in front of them when he tapped his brakes and now their insurance is doubled and they got a ticket. Wow, congratulations!!! You saved yourself $3 per tank and only had to sacrifice yours and everybody else's life while paying a $200 ticket and an extra $1000 a year in insurance, plus a $500 deductible.
You're not getting home any faster in rush hour just because you're rapidly accelerating so you can sit at the next red light waiting for everybody else to catch up. Doing so to save fuel is even more ridiculous than driving slow to save fuel.
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