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Car Fuel Economy and the 55 MPH speed limit
I saw a discussion where someone was advocating a return to the 55 MPH national speed limit to save fuel. Saying that going 55 versus 65 to 75 saves 20% on fuel.
Even if that were accurate, here in NJ with a 55mph limit the roads could not handle the volume, and instead the interstates would become parking lots, consuming vastly more fuel.
I remember the 55mph era, it was great for speeding tickets thats about it!
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Car Fuel Economy and the 55 MPH speed limit
This is (sort of something) I get into on a regular basis, but as it applies to airplanes, not automobiles.
In almsot every case the math doesn't work out in the end as simply as it looks at first.
As an example, I recently mentioned to someone that the fuel consumption rate of my airplane was ~11 GPH (gallon per hour) at cruise speed & altitude. They were sort of shocked. Pilots are a notoriously cheap bunch in some ways. They will nickel & dime everything, then happily spend $100 in gas to fly somewhere, eat lunch and go back home. Thus the famous "$100 hamburger" pilots are so well known for.
In this case however, my plane at 11 GPH covers 160 (statute) miles in an hour, so in automotive terms it gets about 14.5 MPG.
The person I was talking to however, was as I said, rather shocked that I would happily burn that much "extra fuel" (his words) since his plane only used about 8 GPH at a cruise speed of 110 MPH. So by his logic he was using about 3 GPH or about 27.5% less fuel.
The problem is, even though he's burning 27.5% less fuel, he's also traveling slower, about
The difference is however, he's using 27.5% less fuel while traveling about 31% slower.
In the end, he's using more gas to get from point 'A' to point 'B' than I am.
Likewise, if you are driving at 55 MPH instead of 65MPH you are traveling 18% slower, so unless you are getting at least 18% better fuel mileage, you really aren't saving anything.
It's the amount of fuel to get from point 'A' to point 'B' that counts.
Best of luck.
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Car Fuel Economy and the 55 MPH speed limit
A chicken in every pot and a motor scooter in every drive. I'll bet that would get me a long way in politics.
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Car Fuel Economy and the 55 MPH speed limit
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A chicken in every pot and a motor scooter in every drive. I'll bet that would get me a long way in politics.
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You have to update that: McDonald's hamburger and a SUV.
Murf and Dennis you also have to take into consideration value of time and the trips that would not be taken. I would think the airline industry would support this idea. When you get to taking a five hour drive for family vacation or such the extra hour or two would cause many to skip a trip or two. It would seem freight would have to go up that travels by truck.
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Car Fuel Economy and the 55 MPH speed limit
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Saying that going 55 versus 65 to 75 saves 20% on fuel.
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Not in my car. Mercedes designed their cars to get the best fuel economy at the most commonly traveled speeds. I have a 2006 E320 CDI (diesel) that gets >39mpg at 75mph, cruise control and A/C on. But on secondary roads where I have to keep it down under 60mph, I can't do better than 35mpg.
Driving on freeways only - I easily can make it to my daughters house in MN on less than a (21g) tank, elapsed time about 10.5 hours. But taking 55 mph secondary roads, I'd have to stop once for fuel. And the trip would probably take at least 14 hours.
Do I want to return to a national 55 mph limit? HELL NO !!
//greg//
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Car Fuel Economy and the 55 MPH speed limit
Ok, here is a question for the president of "Murf Airlines".
Ok now Murf are you sure youi are factoring in every possible equation?
We've all watched a bird trying to fly into a high wind, try as he might sometines the bird is almost going backwards in relation to the ground below him, so that takes a lot of energy (fuel) to get nowhere right? And I also realize that flying an airplane with a good tailwind may cut your fuel consumption to a point, but you still have to maintain airspeed within the tailwind or kasplat, am I somewhere near right so far?
I've watched small airplanes flying at a diagonal to the direction they want to go to compensate for a cross wind, seems like another fuel guzzler, still somewhat correct?
So as I read your post all things would have too be compared in a dead calm wind situation?
All this is from an old geezer who you couldn't push into the door of another airplane.
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Car Fuel Economy and the 55 MPH speed limit
Gregg_g
I don't want to get in a shouting match about speed limits, but I do think that 55/65, (and MEAN it, fines up the wazoo) for interstate and secondary would be a dooable thing for the safety standpoint alone. I know cars are safer today than when Nixon put the 55 mph limit in force and traffic deaths dropped dramaticly.
Your car may be an exception but I have a hard time believing that every car would get better mileage at a higher speed, it just doesn't factor considering wind resistance etc.
Ok, just my take on it.
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Car Fuel Economy and the 55 MPH speed limit
I'd like to know who that "someone" was who advocated a return to 55. If he/she was a politician it was more likely an excuse to raise revenue through traffic tickets. The hypocritical, double dealing politicians here in Oregon want 55 everywhere *except* between Portland and Salem. That's the route that most of them take to get to work.
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Car Fuel Economy and the 55 MPH speed limit
You know I forgot that we had 21 years of the 55 mph speed limit (1974 to 1995)!
"As gasoline prices surged after the Arab oil embargo of October 1973, Mr. Brinegar used his oil industry expertise to help the Nixon administration develop policies on gasoline refining and marketing. He also led the way in formulating legislation for the nationwide 55-mile-an-hour speed limit, which President Nixon signed into law on Jan. 2, 1974. A 1995 law ended the federal speed limit, giving states the authority to regulate speed limits. nytimes Brinegar passed away this week at age of 82"
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Car Fuel Economy and the 55 MPH speed limit
Ken, no idea there but in our state as many if not most when they are in session they can not be charged for such as your lowly speeding violation. If memory is correct it was felt the locals or such might use false traffic stops to prevent certain elected officials from making a vote.
Our current Lt Governor is well documented on this law as he has benefited from it many times. Vote all the bums out.
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