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Fuel economy can be improved without new engine technology or going hybrid

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    Fuel economy can be improved without new engine technology or going hybrid

    It certainly wouldn't kill the auto industry to add bellypans to their cars, would it? They wouldn't even alter the appearance of the vehicle. The underbody of a car contributes between 13 and 16% of overall aerodynamic drag. This would be a 6-8% boost in fuel economy or so. Yet here they are, looking to save about $50 on each car sold. Other alterations could be made as well as you will see in this article.

    http://www.evworld.com/view.cfm?sect...le&storyid=870


    PHOTO CAPTION: Phil Knox's streamlined 1994 Toyota Tacoma pickup saw its fuel economy go from 25 mpg to 32 mpg at 70 mph just by improving its aerodynamics, reducing its Cd from 0.44 to 0.25, the same as the Honda Insight gasoline-electric hybrid.

    The belly pan was formed from recycled aluminum and sheet metal, as well as discarded bathtub walls from mobile homes.

    Free Fuel Riding on the Wind

    By Jessica Savage

    Your local home improvement store has what you need to significantly improve your fuel economy

    June 29, 2005

    While most Americans are paying more than ever to fuel up their cars, one Texas man has found a way to make gasoline out of thin air - by simply modifying the shape of his half-ton pickup truck.

    Using the principles of aerodynamics, Phil Knox's recent additions of an aero-shell, under-belly pan, rear wheel skirts, wheel covers and grill block to his 1994 T-100 Toyota pickup improved his gas mileage by 28 percent over the original highway mileage.

    Building, testing and educating the public about aerodynamics, is part of the mission of Knox's Independence Technological Works - IT works. "I'm trying to verify claims of aerodynamics going back 70 years," the Denton, Texas man said.

    The passion for aerodynamics awakened in Knox back in 1973 during the Arab Oil Embargo, and after his Air Force tour-of-duty in Vietnam. In early 1974 after reading about the benefits of aerodynamics in Car & Driver Magazine Knox says he was smitten. "Technically, I never recovered from the first oil crisis," he said.

    Using the GI Bill, Knox was educated in mechanical engineering technology at Texas Tech in Lubbock, Texas and soon streamlined his first vehicle - a Volkswagen Bus - with sound fluid dynamic principles. The bus achieved a 28 percent improvement in highway fuel economy just by changing its shape. "I've streamlined every vehicle I've ever owned," he said.

    Typically, Knox can be found at gatherings such as an Earth Day celebration, handing out flyers and preaching the environmental gospel of aerodynamics, or out road testing his latest innovation. "When you go to a car lot - this isn't fertile ground for a conversation in aerodynamics with the sales people - they don't know the language," he says. The general terms of aerodynamics - drag co-efficient, airflow patterns, frontal area, aspect ratios, fluid dynamics - are not part of everyday conversation.

    "I found out by accident," Knox says, "You live it everyday but you don't have the vocabulary to ever talk about it."

    From a strictly Capitalist point-of-view, vehicles that are not aerodynamically efficient are losing money and not showing a good return-on-investment. "The business of America is to make money," Knox said, referring to the Horatio Alger quote. So Knox is compelled to urge people to stop buying gas-guzzling trucks and SUVs. "Stop the rags to riches trend these vehicles are setting for America," he advises. "Buy two fuel-efficient cars instead."

    The worst offender is the Hummer, Knox said, which when compared to a hybrid car, is like losing 600 percent of a transportation investment. "It's like buying six dinners, eating one and leaving the other five," he said. "It's like stealing fuel from five families." What's worse, Knox says, is Hummers and large pickup trucks are eligible for up to $25,000 in tax break exemptions by being considered farm equipment, while the Environmental Protection Agency says these are the last kind of vehicles America needs on it‘s roads.

    But it's not the huge size of these vehicles that's responsible for their terrible gas mileage - it's their bulky shapes.

    "It all goes back to Eiffel in 1895," Knox said, "Basically he nailed it." Knox is speaking of Alexandre Gustave Eiffel, the famous French engineer who designed the Paris landmark - the Eiffel Tower. After a career designing bridges and other iron structures all over Europe, Eiffel settled down to conduct experiments in aerodynamics and meteorology, some done right on the tower. These pursuits are actually an extension of architecture because aerodynamics is a huge component of the design of large structures that will be subject to lots of wind once erected.

    What Eiffel discovered, Knox said, is that a shape that looks oddly like an ice cream cone, was able to fall off the tower faster than any other object sent down the test cable. "Below 250 miles-per-hour, it's the best shape for a vehicle - an ice cream cone chopped in half with four wheels on it," he said, "It's hard to improve upon."

    The world's fastest cars that set speed records are this shape. GM, Ford, Mercedes, Volkswagen, Volvo, Oldsmobile, GMC Trucks and others all use this technology to set records, Knox said. Even NASCAR teams admit that their cars would go faster "backward," as they would take on more of the "teardrop, double-end, pumpkin seed or ice cream cone shape, he said.

    While most people don't want to drive around in a car that looks like a race car, they won't need to. An egg, as opposed to a sugar-cube shape with a tapered back is what delivers the benefits of aerodynamics. A counter-intuitive example of this principle is a truck pulling an aerodynamic trailer. Without the trailer, the air behind the cab and tailgate is in the form of turbulence or eddys, creating drag on the vehicle. An aerodynamic trailer streamlines the vehicle and the air flowing over it is smooth and without resistance. "Mass is important but once up to highway speed, a truck with an aerodynamic load can get potentially higher gas mileage," Knox said. Consider that there are 40-ton aerodynamic 18-wheelers that get better gas mileage than Hummers. Knox once pulled a 1,300-pound "aero-trailer" behind his Honda CRX and still got 50 m.p.g.

    What questions should vehicle shoppers ask when considering the aerodynamic qualities of their next car?

    Here's Knox's suggestions:

    What is the vehicle's coefficient of aerodynamic drag (Cd)? These numbers rate the shape of the vehicle, regardless of size. For example, a parachute has the most drag of all and has a Cd of 1.35, while Honda's Dream Solar Champion has a Cd of 0.11. Frontal area: measured in square feet, the frontal area of a vehicle measures the area of air displaced as it advances through the air.

    Together, the frontal area and Cd form a vehicle's "signature" or drag index. "Air has mass and you can't go through it without paying for it," Knox said. Large streamlined cars and pickups can go as easily through the air as small, ill-designed "econo-boxes," he said.

    By asking questions about the aerodynamics of a vehicle, it will force auto dealers to learn about the qualities of aerodynamics. Buying a car that's not aerodynamic is like buying a house without insulation, Knox said.

    Anyone could make their vehicle more aerodynamic using the methods Knox used to reshape his T-100 pickup truck. To form the aero-shell that reshapes the cab of the truck, Knox cut rigid foam insulation board into the shape he wanted with a razor blade and covered it with fiber glass, affixing it with a resin glue composite. The belly pan was formed from recycled aluminum and sheet metal, as well as discarded bathtub walls from mobile homes. The grill was blocked off on the outside. Most materials are available at home improvement stores.

    To test the fuel efficiency of the truck, Knox drove roundtrip from Denton to Odessa at 70 m.p.h. and achieved a 32 m.p.g. fuel efficiency. A test conducted six months prior to that with only the aero-shell - same route and same speed - achieved 27.5 m.p.g. The truck is rated 25 m.p.g. standard. Toyota publishes a drag co-efficient of 0.44 but with the modifications the truck had a drag co-efficient of 0.25, which is equal to Honda‘s Insight hybrid car, Knox said. No other modifications were made.

    "We haven't touched anything under the hood," Knox said, "It's purely through streamlining and drag reduction. Everything is stock, even the tires." Aerodynamics or vehicle shape is the technology that will reduce foreign dependency of oil and empower Americans in fuel efficiency, Knox said.

    Whether the fuel source is gasoline or diesel, or an environmentally-friendly source like a hybrid electric or hydrogen fuel cell, applied aerodynamic principles will deliver more miles per gallon.

    "It's free horse power, free speed, free reduction in emissions, free fuel," Knox said. "It's like creating synthetic fuel out of thin air."

    END STORY
    Last edited by The Toecutter; 07-02-2005, 02:13 PM.
    The unnecessary felling of a tree, perhaps the growth of centuries, seems to me a crime little short of murder." ~ Thomas Jefferson

    #2
    Re: Fuel economy can be improved without new engine technology or going hybrid

    Unfortunately, I think it probably would cause fake death-throes in the auto industry if the EPA required that extra part. Why? Because if big business b---hes enough Bush will come to their rescue with a veto.

    I think Bush is trying to make up for past failures by trying to show that he isn't a failure as a businessman (even though "failed businessman" is the very definition of "politician").

    Anyway, SUV's and pickups are the bread and butter of the auto industry and nothing short of a total consumer boycott clearly related to gas mileage will convince them to change the formula. That and the intimate relationship between the fuel industry and auto industry is a stumbling block.

    Comment


      #3
      Re: Fuel economy can be improved without new engine technology or going hybrid

      That intimate relationship is why we don't have electric cars as we speak. There's a topic I recently made on just how fast battery-powered cars can be.

      The auto industry sees to it that it will maximize profits above all else, even skimping on a $50 belly pan which would save the consumer many hundreds of dollars over the life of the vehicle in saved fuel...
      The unnecessary felling of a tree, perhaps the growth of centuries, seems to me a crime little short of murder." ~ Thomas Jefferson

      Comment


        #4
        Re: Fuel economy can be improved without new engine technology or going hybrid

        So, those electric cars can go fast. Could they keep that speed up for long periods of time?

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          #5
          Re: Fuel economy can be improved without new engine technology or going hybrid

          I've also heard that hybrids can run exclusively on battery power without running down the batteries. Though you can't go more than 25 MPH or turn on the radio, AC, or any other accessories w/o making the gas engine turn on.

          I think I read something you wrote about how fast electric cars can go awhile back. The average person doesn't really need to go faster than about 75-80 MPH, though, unless they're a dumbass, then they'll lose their license or die in a crash anyway, so it's all good.

          Comment


            #6
            Re: Fuel economy can be improved without new engine technology or going hybrid

            What do you mean by a long time? At 150 mph, a gas car isn't going to go very far either, as mpg will drop to like 4 or 5. Range of my car is simulated to be about 12 miles @ 150 mph when it's finished, while in normal driving @ 60-70 mph, 80-100 miles per charge, just to give you an example.

            This is on cheap lead acid batteries who are further harmed by Peukert's effect, which basically means the more current you draw over a period of time, the less of a lead acid battery's capacity will be delivered. Lead acid batteries have capacity measured at the 20 hour rate in amp hours, but the 1 hour rate, which would be more realistic for a lead-acid battery equipped EV, you might see half the 20 hour capacity for a low Peukert's exponent sealed lead acid battery. The more power required of the car, the more amps will be drawn, and as speed increases, required power also increases as a function of all losses associated with the car.

            The equation for Peukert's capacity is as follows:

            Peukert's Capacity = (Amps^Peukert's Exponent)*Time in Hours

            Peukert's capacity is measured in amp hours at the battery's 20 hour rate. You solve for the time in hours and multiple by the amps to figure out what the batteries delivered amp hours will be.

            Note how those aerodynamic principles used in this truck are routinely exploited in hybrids to maximize fuel economy and electric vehicles to maximize range.

            This truck could be taken, have a flip-top bed installed, and have the entire underside of the bed loaded up with sealed lead acid batteries like Optima D750 Yellow Tops or Excide Orbital Deep Cycles, along with the engine compartment loaded with the same, and be equipped with an 11'' Kostov Motor and a Zilla 2k controller. It would have about 150 miles range with about 2100 pounds of batteries and over 250 horsepower from the motor and in excess of 700 lb-ft of peak torque. The flip-top bed would cover the batteries, so as to keep the batteries from having to be placed on the bed itself which would otherwise take up space.

            But even kept as a gas-powered truck it has shown the merits of improved vehicle efficiency. Imagine what would happen if the guy would machine his brakes down to be perfectly round, equip the truck with low rolling resistance tires like Invitica GLRs or some such, replace his wheel bearings, run redline MTL or some other synthetic transmission oil designed for low viscosity, and adjust his alignment to zero degrees camber to cut steering drag. He'd be pushing 35 miles per gallon, still with no engine modifications whatsoever, in a truck none the less.

            I think I read something you wrote about how fast electric cars can go awhile back. The average person doesn't really need to go faster than about 75-80 MPH, though, unless they're a dumbass, then they'll lose their license or die in a crash anyway, so it's all good.
            Looks like I'm headed down that path. My sports car's about as small as the Porsche Spyder James Dean got killed in!
            Last edited by The Toecutter; 07-03-2005, 03:41 AM.
            The unnecessary felling of a tree, perhaps the growth of centuries, seems to me a crime little short of murder." ~ Thomas Jefferson

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              #7
              Re: Fuel economy can be improved without new engine technology or going hybrid

              As long as you're not driving one of those completely ridiculous low-rider pickups. One caught fire in a crash and they say the modifications to the fuel tank was the cause of the fire. It doesn't help that the mayor's wife was involved in the crash, either. Nobody was hurt, but the pickup, which was not at fault for the accident, just to get things straight, was DOA.

              I guess you have to figure that without moving the gas tank into the bed (Which reduces the utility of these trucks even more, considering you couldn't load anything heavy in there, anyway, without f--king up the undercarriage) it'll be the 4th of July every time one of those things hits a speedbump.

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                #8
                Re: Fuel economy can be improved without new engine technology or going hybrid

                The beauty of an electric truck is that batteries don't explode like gasoline does. You can slip them right under the bed, lower the center of gravity significantly, make it handle like a sports car, and slightly increase towing capacity with the added weight(Would need suspension modifications to alter GVWR specifications).
                The unnecessary felling of a tree, perhaps the growth of centuries, seems to me a crime little short of murder." ~ Thomas Jefferson

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