Can a fleet manager set a top speed on the vehicles using existing ECM

Written by Administrator
Monday, 08 September 2008
While it is possible to reprogram the ECM on vehicles built since 1996 it does require special software.  There are firms that offer "Flash" ECM programming services, but only to factory specifications and to enhace performance for higher speeds, but not for a lower top speed. It seems it will take aftermarket add on equipment for fleet managers to be able to set a top speed on their vehicles at this time. This could be a real opportunity for some smart software people...

Here is a UK company that sells aftermarket speed limiters:
http://www.autokontrol.com

Driving slower takes longer and therefore burns more fuel

Written by Administrator
Thursday, 21 August 2008

Q: If it takes you longer to get somewhere that means your vehicle is running for a longer period of time and thus burning fuel & polluting for a longer amount of time negating all the good you did by slowing down?

 A: Let's say you have a vehicle that gets 18 MPG at 80 MPH and 25 MPG at 55 MPH. If you had only 1 gallon of gas to use and wanted to travel 25 miles, what will happen if you try to make it at 80 MPH? Unless your vehicle is also breaking the laws of physics, you will run out of gas at about 18 miles so you will have to use more fuel to go the rest of the way. A lot more fuel. Let's look closer.

To figure the extra fuel required, we need to know the gallons per mile for each speed, based on 25 MPG @ 55 MPH and 18 MPG @ 80 MPH
MPH - Gallons per mile
55 --- 1/25 = .04

80 --- 1/18 = .055

So, 25 miles X .055 gals per mile = 1.375 gallons will be required to travel the same 25 miles, which is a  37.5% increase in consumption. Do you see how the increase is exponential? Waste increases with speed. Pollution increases with waste in the same exponential way.

How much can we really save?

Written by Administrator
Tuesday, 29 July 2008
Opponents claim the reduction in consumption will be minimal and may base their claim on a 1986 Heritage Foundation article entitled "The High Cost of the 55 MPH Speed limit". The article concedes overall consumption was reduced between .5 and 2% and goes on to explain that over 71% of drivers ignored the law while local municipalities manipulated data and many states actually enacted legislation specifically to preempt the federal law. So, using their own data, despite all the non-cooperation, consumption was reduced anyway and it was done by less than 30% of drivers!

Drive 55 Conservation Project research proves much greater reductions of 20-50% are possible when drivers actually observe ALL speed limits never exceeding 55 MPH. Senator Warner is asking DOE and GAO to answer this question in light of the latest technology, population and economics. We all look forward to the official response.

Meanwhile, you can prove it for yourself, download and print a Real World Vehicle Efficiency Report and fill it in to calculate your savings.

My time is worth more

Written by Administrator
Tuesday, 29 July 2008

Most trips are about 30 miles or less on busy local roads, not lonely stretches of desert. Even if all 30 miles are on a freeway, slowing down will actually only cost a few minutes per trip. Reduced congestion due to fewer collisions and more efficient use of the roads offset  the minimal time difference.

See also:

Time Value vs. Speed

Independent truckers earn more @ 55 MPH

Are We Really Serious About Saving Money On Gas?

My vehicle gets better mileage at higher speeds.

Written by Administrator
Tuesday, 29 July 2008

No vehicle can violate the laws of physics , the faster you go the more energy it takes. It IS rocket science, but simple enough to understand if one is willing to accept the truth. Speeders are addicted to the sensation and will go to great lengths to feed their desire.

The power required to overcome the aerodynamic drag is given by:

Note that the power needed to push an object through a fluid increases as the cube of the velocity. A car cruising on a highway at 50 mph (80 km/h) may require only 10 horsepower (7.5 kW) to overcome air drag, but that same car at 100 mph (160 km/h) requires 80 hp (60 kW). With a doubling of speed the drag (force) quadruples per the formula. Exerting four times the force over a fixed distance produces four times as much work. At twice the speed the work (resulting in displacement over a fixed distance) is done twice as fast. Since power is the rate of doing work, four times the work done in half the time requires eight times the power.

Source: Wikipedia

 

Small Cars Save Big at 55 MPH

Written by Administrator
Monday, 01 September 2008

The amount of energy saved as a result of drivers observing ALL speed limits and never exceeding 55 MPH will increase over time as the vehicle fleet of large units is replaced by smaller "downsized" models. While slowing down reduces energy consumption for all vehicles, smaller vehicles fuel economy suffers more at high speeds than larger vehicles do. In fact, as the following chart shows, at speeds over 70 MPH a small vehicle will use nearly as much energy as larger ones, negating the benefits of its smaller size and weight!

This is not to excuse the illogical practice of overpowering vehicles that are too big and heavy, these waste more at any speed. Rather, this demonstrates again why everyone needs to slow down to observe ALL speed limits and never exceed 55 MPH to save 20% - 50% right now with NO new technology, especially small vehicles!

Will shipping rates go up because everything will take longer to be delivered?

Written by Administrator
Tuesday, 29 July 2008

Actually, shipping rates will go up as energy costs rise unless truckers do something to help offset the increase. For those shipping with companies using speed limited trucks there will be less wasted energy to pay for. All the big companies have known this for a long time and routinely use governors on their rigs.

Consider this example:
Let's each take a load 825 miles @ $1.30 per mile = $1072.50. We will pay $5 gallon for fuel. You will drive 75 MPH and get 5 MPG ($1 per mile) and I'll go 55 MPH and get 7 MPG (.71 cents per mile).**

You will get there in 11 hours and spend $825 on fuel for a gross profit of $247.50, divided by 11 hours works out to $22.50 per hour. It will take me longer, 15 hours, but I only spend $585.70 on fuel so my gross profit is $486.8 divided by 15 = $32.45 per hour. Granted I will have a ten hour sleep period, but when I wake up and hit the road it will be at $32.45 an hour and you will still be getting $22.50. Correct me if I'm wrong, but with fuel at $5 gallon it looks like you could earn an extra $10 an hour when you Drive 55.

** "Excessive speed is the largest single factor in reduced fuel mileage. A general rule of thumb is that every mph increase above 50 mph reduces fuel mileage by 0.1 mpg."
Kenworth White Paper on Fuel Economy, March 2006. http://www.kenworth.com/FuelEconomyWhitePaper.pdf

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Via email Roger Pomerleau writes:

I lowered the maximum speed on my commercial fleet of 60 Tractor Trailers by 4 MPH and saved 70,000 gallons of diesel fuel in a year... that's $300,000.

If the speed limit could be maxed at 55 I could save 150,000 gallons more or an additional $ 675,000.

It is just not safe to drive tractor trailers at 55 until the law is changed.

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Also see:

Nations Largest Truckload Carrier Becomes Most Energy-Efficient Fleet

Con-way Freight CEO supports national speed limit

 

Will there be more congestion if everyone is driving slower?

Written by Administrator
Tuesday, 29 July 2008
What about congestion from slow drivers? Congestion will actually decrease due to reduced collisions providing an increase in productivity rather than a decrease.

Consider this metaphor from the Missouri DOT website; "If traffic slows down as they approach a congested area and all the drivers stay at a constant speed, traffic will get through the congested area faster. Imagine the highway as a funnel. Now, imagine the traffic which has to travel along the highway during a certain time as a container of rice. If you pour all the rice into the funnel at the same time, it gets congested at the bottom of the funnel and takes some time to work through the funnel.  Now, if you slowly pour the rice into the funnel – keeping it at a steady pace – the rice moves through the funnel evenly and doesn’t cause congestion. In fact, even though the rice is entering the funnel slower, all the rice gets through the funnel (to its destination) faster.
Note: this metaphor is based on an idea from Paul Haase of Sammamish, Washington, in response to a challenge by Washington State Department of Transportation Secretary Doug MacDonald."
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