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-   -   Latest high-stakes MPG contest (https://www.fuelly.com/forums/f8/latest-high-stakes-mpg-contest-11070.html)

theholycow 04-08-2009 12:25 PM

Latest high-stakes MPG contest
 
https://www.newscientist.com/article/...ef=online-news
Quote:

Last night in California a list of 111 teams was announced – one of which may hold the key to motoring's green future. They are the registered entrants to the Progressive Auto X Prize, a contest that will award prizes totalling $10 million for vehicles that can go 100 miles on the energy equivalent to that in a gallon of fuel.

Notable by their absence were the world's largest car manufacturers – bar Indian firm Tata – who don't seem interested in taking part. The list is varied spanning slick Californian start-ups with electric cars, to less-refined backyard efforts still finalising their designs.
[...]
The main $7.5-million purse for designs with four wheels, carrying four people requires they travel 200 miles on one load of their chosen fuel – at the target efficiency – and must accelerate from 0 to 60mph in 12 seconds and reach speeds of 100 miles per hour.

The smaller $2.5-million prize for vehicles of any design carrying two or more people requires they go 100 miles on a top-up and reach at least 80 mph. Both categories restrict carbon emissions and require attainable plans to manufacture 10,000 vehicles a year.

Lug_Nut 04-08-2009 04:05 PM

Quote:

The main $7.5-million purse for designs with four wheels, carrying four people requires they travel 200 miles on one load of their chosen fuel - at the target efficiency - and must accelerate from 0 to 60mph in 12 seconds and reach speeds of 100 miles per hour.
Hopefully the acceleration and top speeds don't require the three passengers, and those two tests aren't incorporated as concurrent with the 200 mile on less than 2 gallon portion.
We're close, real close. I expect this to have been won within 5 years.

GasSavers_maximilian 04-08-2009 04:09 PM

0 to 60 in 12 seconds is much better than the Tata Nano can do, interestingly. Did a quick search and 0-60 is like 25 seconds for the Nano (a review said it was even longer). I realize the Nano is intended mostly for cities, but it still makes the 12 second requirement seem a little stiff. Encourages low weight I guess. 100 mph seems high too, but that is for the big prize at least.

Just checked and a Fortwo wouldn't meet the acceleration or top speed requirements. It's top speed is limited though, so maybe it could reach it. The point is that the X-Prize isn't making it easy.

I didn't see anything in the article or the wiki page on this about safety requirements. Anybody know about them? If you don't need to consider safety, shedding weight gets a lot easier.

GasSavers_maximilian 04-08-2009 04:17 PM

Found something on it with a bit more searching. They have to meet U.S. federal crash safety requirements, apparently. Figured they must've had something or it'd be pointless.

R.I.D.E. 04-08-2009 04:27 PM

100 MPG, thought it was 5 passengers.

mass production capable with a price below 30 K.

The 4 wheelers wont make it.

The specialty vehicles will, but they don't get the big prize.

Signed up as a potential entry, was either 5 or 10 grand to enter. Got a crapload of spam emails for months afterward.

regards
gary

GasSavers_maximilian 04-10-2009 03:56 AM

It'd be interesting to calculate the minimum efficiency they'd need to complete the challenge. Stealing some text from a website, the road load power is:
a*v + b*v^3 + c*v^3

The a component comes mostly from the rolling resistance of the tires, and friction in the car's components, like drag from the brake pads, or friction in the wheel bearings.

The b component also comes from friction in components, and from the rolling resistance in the tires. But it also comes from the power used by the various pumps in the car.

The c component comes mostly from things that affect aerodynamic drag like the frontal area, drag coefficient and density of the air.
Once we know those constants, computing overall efficiency is straightforward. So what are good estimates for reasonable cost (< 30k) attainable values of a, b, & c? I have to believe you guys would have a better feeling for that than I, so I'll defer to your opinions.

All this assumes that 200 mi trip is highway with no stops, of course. Trying to get more advanced would become complex way too fast. Can just see this as a lower bound.

*edit* Now that I think about it, this will tell us very little by itself. Without any low speed efficiency measures or hills, weight doesn't factor in. With ultra low weight you can make crazy efficient vehicles, but they'd never meet the other requirements.

Rats.

Sludgy 04-10-2009 05:59 AM

In this contest, the deck is stacked towards electic cars. The criterion is the "energy equivalent of a gallon of gasoline", or about 115,000 BTU.

A battery holding 115,000 BTU of energy has 34 kWh of electrical energy. An electric car can use nearly all of that 34 kWh because the motors are about 90% efficient.

A gas engine is at best 30% efficient, so it will have to make do with just 10 kWh of energy.

This bias does not include the energy lost in generating electricity at the power station or the loss in transmission through the grid and in battery charging.

It's really unfair to gas or diesel powered cars.

GasSavers_maximilian 04-10-2009 06:02 AM

Quote:

Originally Posted by Sludgy (Post 132253)
This bias does not include the energy lost in generating electricity at the power station or the loss in transmission through the grid and in battery charging.

It's really unfair to gas or diesel powered cars.

That is completely ridiculous! Fossil fuel vehicles have hidden costs as well, but not anywhere near to that level! Any requirement for speed of refueling/recharging?

Sludgy 04-10-2009 12:19 PM

Quote:

Originally Posted by maximilian (Post 132254)
That is completely ridiculous! Fossil fuel vehicles have hidden costs as well, but not anywhere near to that level!

Instead of issuing a cheap shot, you could back up your claim with some data.

GasSavers_maximilian 04-10-2009 12:23 PM

Uh, I was agreeing with you...I meant that their bias is completely ridiculous and that whatever hidden costs fossil fuels may have, they are dwarfed by the electric car costs they're neglecting. Makes me wonder where they think these cars will run...Iceland?

Lack of tone and inflection strikes again! Sorry for the misunderstanding.:o


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