« Boy Scout Recreates X PRIZE Cars, LEGO Style | Main | What Do Scouts Prize? »

Comments

Adrian Russell-Falla

wtf happened with Aptera pulling a DNF after 18 laps???

James

Less than a year ago they were saying they got 300 MPG. Which is it?

Eric Cahill

Well, now we have a more objective measure on which to base any automaker's claim. We could similarly put GM's Volt and Nissan's Leaf through the same Progressive Insurance Automotive X PRIZE test protocol and compare MPGe, which factors in all energy sources used to move the vehicle, with MPG, which only factors in gasoline energy. We make the case that MPGe should be the standard on which to compare efficiencies of thenext generation of cars that use a variety of fuels and energy sources.

Pete

The 300 MPG is with a fully charged battery, so if you plug it in every night, and drove around a bunch every day, it would average out to about that. They said as much on their website, but it was a bit confusing and I had to dig it out as well...

Kevin

Neither. MPGe is a bogus measure which ignores how much fuel was burned in the power plant. At 178.2 MPGe (calculated per X-Prize rules), the Aptera actually burned the same amount of fossil fuel and produced the same amount of CO2 greenhouse gasses as a 90 MPG gasoline vehicle. It actually used ENERGY equivalent to approx. a 75-80 MPG car, because even the 90 MPG calculation was "giving for free" the fraction of electric power that currently comes from green sources. Still very good mind you, but we should reject the fantasy math the X-Prize and eCar folks use. It only serves to obscure reality and confuse people.

Kevin

Neither. At the 178.2MPGe, the car used the same amount of fossil fuel (at the power plant) and emitted the same amount of CO2 as a gasoline car of 90 MPG. This can easily be calculated using the X-Prize's spreadsheet. Pretty good!

Roger

300 MPGe is most likely measured under ideal conditions, such as 55 MPH on a level straight road with no head wind. The race conditions would be as close to 70 MPH as was possible, with the added effects of the chicane, causing energy waste in the brake system, as hard braking engages traditional brakes that cannot recover energy.

Michaelc

"MPGe is a bogus measure which ignores how much fuel was burned in the power plant. "

By that reasoning, MPG is bogus too since it does not include the fuel expended in the creation of the gas.

Josephl

Good point Michaelc re MPG being bogus also. One needs to compare apples with apples..unless someone has an ulterior motive.

Alan

The problem with people obsessed with counting every last fly speck in the pepper is that they are comfortable with fly specks in their pepper. They are moving ahead to increase your "fuel mileage" by hundreds of percent and you have lost sight of the "big picture".

DavidA

Yeah; very difficult to compare apples to apples across energy source types. Everyone has motives and biases, even if they're trying to be even-handed. XPrize is as close to a disinterested party as you'll find; so I have a level of trust that's much higher than what I'd have for any particular manufacturer, trade group, or for that matter, government, given the sway held by lobbying interests. Personally, I side with EV's as a group. The core infrastructure is already present, the efficiencies are hard to deny, and I think we'll have an easier time greening the grid, than we will dealing with ethanol, biodiesel, or hydrogen. But hey, what's wrong with pursuing all of them at the same time? Good ol' all-American competition and innovation charging ahead full-bore(no puns intended).

Jim Bullis, Miastrada Company

Coal and gasoline (or E85) are the relevant fuels to compare.

Heat engines have to be fired up to make the cars of either type go. Honesty would require that the huge impact of these heat engines be included. If the amount of heat into the system was used as the starting point, a reasonably fair comparison would be possible, and the processing and transportation burdens would roughly cancel out.

This gives a factor of three advantage to the electric cars that is entirely inappropriate.

The upshot of the miscalculations is that relatively sloppy engineering of the electric cars gets "mpge" that is far in excess of the real mpg for very carefully built cars that carry their own engines.

Sure, in 50 years there might be renewable power and this will not be important. But then there will be no need for phony "mpge" which would be especially meaningless.

We should realize that the premise of "mpge" is that electricity is a fuel that flows from a plug. Then the calculation is based on the 'freshman fool physics problem,' where the fact that heat and electricity are measured in units of kWhr tricks the indolent into thinking they are equivalent forms of energy that can be exchanged. (I know, I fell for it on a pop quiz, but fortunately got it together for the real exams.)

Nobody should feel bad for falling for this; after all even Dr. David MacKay has promoted this falsehood in his book, and he is the Senior Advisor to the UK Dept of Energy and Climate.

David Arellanes

Come on people - try to remember the "big picture" - to cut the use of fossil fuels - to cut the co2 - to work toward clean renewable energy sources to power our transportation vehicles. I don't have a problem with those taking the negative position on test results - but within your comments seems to be a "failure motive" of 'nothing will work well enough so why bother'! I suggest you work the negative side of the equation, but with the objective of making suggestions or ideas to move the project forward. Don't just claim 'it's all just BS or bogus' an then feel satisfied with your input. Work to find an answer to whatever problem you believe you see, or there is, with the project. These vehicles will change the way our entire world is cared for. It will improve our environment, improve people's lives. The big picture - and the long run - is what really counts when working to make real, positive and long term improvements.
Join the work - don't just give it grief!

Ed

Aptera has stayed on my mind since I first heard about it. Very innovative. Then, they hired those auto people. Soon the design changed. Mirrors appeared. The easily interchangeable and simple rear drive system was abandoned for more complicated and expensive front wheel drive. It got wider, heavier. Soon the only thing lacking will be that fourth wheel they are working toward.

BAH. I remember a sign on a conference room wall about ways to kill a good idea. I think there were 10. Was one of them "...but we can improve it by ..."?

Well, it WAS a good idea.

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Working...
Your comment could not be posted. Error type:
Your comment has been saved. Comments are moderated and will not appear until approved by the author. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.

Working...

Post a comment

Comments are moderated, and will not appear until the author has approved them.

Your Information

(Name and email address are required. Email address will not be displayed with the comment.)