Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Gas Pods

ChazInMT · 11-25-2012, 10:56 PM

Susanne,

Do you not see that we're skeptical here for 4 reasons.

1st, we know that anecdotal evidence, even over vast amounts of time, is worthless. Your test team is biased because in general people are not going to spend around $100 on something and then report negatively on it. It's marketing 101 stuff, they'd make themselves look like idiots for buying them. People who get positive results are far more likely to report them than those who get negative numbers. In addition, your test team is going to, in all likelihood change other things about how they drive and maintain their cars in order to save fuel. The gaspod things are just one of several elements in their fuel savings efforts so to credit all the fuel savings to the gaspods is just silly.

2nd, to achieve a 10% savings in fuel, the gaspods would need to reduce the aerodynamic drag on the vehicle by 20%. 20% is a HUGE reduction in the Cd of a car, if the gaspods could do this, they'd be on every production car made these days. For a 20% savings, your devices would need to reduce drag by 40% on a car. Really? Automobile companies are spending millions to try and save 2-3%. We here understand these numbers and realize that gaspods alone CAN NOT be responsible for more than a few percent savings if any, so your bragging up 10,15, & 20% savings numbers again seems disingenuous and silly.

3rd, CFD testing is suspect because the program can be written to favor you. It is also a Hugely complicated problem to try and ask a computer what is going to happen with air flow simulations. To those who don't know any better, using a computer to test an aerodynamic element on a car is a good idea. To those of us who understand better, and know the limitations of the all-powerful computers, we know this is at best, a crude tool for letting us know whether we may be on the right track. Don't go giving us some NASA engineer mumbo jumbo either, we're celebrating 100 years of flight here and greater minds than yours, mine, and your engineer cannot agree on how exactly it is that an airplane flies, specifically, how is lift created. You wanna put that to the test start a thread in here regarding the theory of flight and watch the feathers fly. Might as well put a Baptist preacher and a died in the wool atheist in the same room and have them discuss the great hereafter.

4th, I and others have offered you an easy, low cost, very accurate method of determining whether the gaspods are actually reducing the aerodynamic drag as you purport by doing a coast down test, or by finding a hill and rolling down it in neutral with and without the gaspods in place and comparing the results. Within 2-3 hours of testing (which is less time than you have dedicated to reading and responding to these posts in here) you could have raw data that would be very difficult to dispute regarding the positive benefits of your devices. Yet you do not seem willing to do something this easy saying instead, you'd rather rely on methods which are not at all scientific in nature as proof your gaspods are effective. We here would be happy to draw up a testing protocol giving instructions to make it straight forward what needs to be done.

If you are genuine in your effort to sell a drag reducing device, why would you not do this simple coasting test? Why not ask people in your test fleet to do the same? It can’t be time or money. Is it that you’re afraid the real world results will indeed prove a tiny, if any, improvement would result in a very long term payback?

Whatta ya think?

11-25-2012, 10:56 PM	#21 (permalink)
ChazInMT Aero Deshi Join Date: Jan 2010 Location: Vero Beach, FL Posts: 1,065 MagMetalCivic - '04 Honda Civic Sedan EX Last 3: 34.25 mpg (US) Thanks: 430 Thanked 669 Times in 358 Posts	Susanne, Do you not see that we're skeptical here for 4 reasons. 1st, we know that anecdotal evidence, even over vast amounts of time, is worthless. Your test team is biased because in general people are not going to spend around $100 on something and then report negatively on it. It's marketing 101 stuff, they'd make themselves look like idiots for buying them. People who get positive results are far more likely to report them than those who get negative numbers. In addition, your test team is going to, in all likelihood change other things about how they drive and maintain their cars in order to save fuel. The gaspod things are just one of several elements in their fuel savings efforts so to credit all the fuel savings to the gaspods is just silly. 2nd, to achieve a 10% savings in fuel, the gaspods would need to reduce the aerodynamic drag on the vehicle by 20%. 20% is a HUGE reduction in the Cd of a car, if the gaspods could do this, they'd be on every production car made these days. For a 20% savings, your devices would need to reduce drag by 40% on a car. Really? Automobile companies are spending millions to try and save 2-3%. We here understand these numbers and realize that gaspods alone CAN NOT be responsible for more than a few percent savings if any, so your bragging up 10,15, & 20% savings numbers again seems disingenuous and silly. 3rd, CFD testing is suspect because the program can be written to favor you. It is also a Hugely complicated problem to try and ask a computer what is going to happen with air flow simulations. To those who don't know any better, using a computer to test an aerodynamic element on a car is a good idea. To those of us who understand better, and know the limitations of the all-powerful computers, we know this is at best, a crude tool for letting us know whether we may be on the right track. Don't go giving us some NASA engineer mumbo jumbo either, we're celebrating 100 years of flight here and greater minds than yours, mine, and your engineer cannot agree on how exactly it is that an airplane flies, specifically, how is lift created. You wanna put that to the test start a thread in here regarding the theory of flight and watch the feathers fly. Might as well put a Baptist preacher and a died in the wool atheist in the same room and have them discuss the great hereafter. 4th, I and others have offered you an easy, low cost, very accurate method of determining whether the gaspods are actually reducing the aerodynamic drag as you purport by doing a coast down test, or by finding a hill and rolling down it in neutral with and without the gaspods in place and comparing the results. Within 2-3 hours of testing (which is less time than you have dedicated to reading and responding to these posts in here) you could have raw data that would be very difficult to dispute regarding the positive benefits of your devices. Yet you do not seem willing to do something this easy saying instead, you'd rather rely on methods which are not at all scientific in nature as proof your gaspods are effective. We here would be happy to draw up a testing protocol giving instructions to make it straight forward what needs to be done. If you are genuine in your effort to sell a drag reducing device, why would you not do this simple coasting test? Why not ask people in your test fleet to do the same? It can’t be time or money. Is it that you’re afraid the real world results will indeed prove a tiny, if any, improvement would result in a very long term payback? Whatta ya think?