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Efficiency is a Joke

02/17/2013 11:36 PM

The efficiency of a modern automobile running on gasoline or diesel is only about 12%. This hasn't changed much since the model T. The self drive car will bring about the first really major change in the functionality in the automobile in 100 years. It might even make efficiency a priority, as no lead foot human will be behind the wheel, it might not even need manual controls, just verbal commands.

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#1

Re: Efficiency is a joke

02/17/2013 11:56 PM

Your numbers are way off.

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#2

Re: Efficiency is a joke

02/18/2013 12:01 AM

I make it 25% efficiency, and I'll do the driving, thank you.

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#3
In reply to #2

Re: Efficiency is a joke

02/18/2013 12:23 AM

I'll see your 25% and raise you a hydrocarbon fuel cell with wheel motors.....

". The energy efficiency of a fuel cell is generally between 40-60%, or up to 85% efficient if waste heat is captured for use."

http://en.wikipedia.org/wiki/Fuel_cell

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#5
In reply to #3

Re: Efficiency is a joke

02/18/2013 3:00 AM

You seriously need to get that wheel fixed
Del

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#6
In reply to #5

Re: Efficiency is a joke

02/18/2013 5:39 AM

It's those danged Samurai road warriors.....

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#4

Re: Efficiency is a joke

02/18/2013 2:06 AM

We already have self flying planes. That will show us the way for self driven cars!

Right?

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#7

Re: Efficiency is a joke

02/18/2013 9:22 AM

Self drive car:

Do you have any idea what it takes to design, monitor, and maintain fail-op electronics? This has always been implemented as triple channel redundant type systems. You can't do that with off the shelf hardware (microprocessor hardware unless you can analyze it). You won't see fully automated systems with voice command, you can't guarantee that under stress you can tell the damn machine to stop. And if any channel fails, it will be required to coast to a stop, and discontinue any operation. These are called Critical safety systems. And will have the same regulatory requirements as the nuclear power, and aviation industries. Although it's the amount of people you can kill at one time that will drive the actual safety numbers that regulatory agency (DOT in USA) will require.

I know Mercedes Benz has in it's recent advanced design, decided to NOT automatically stop the car if an accident was eminent, as they did not want the product liability of failures and ensuing lawsuits. That could change in the future, but I doubt it.

Remember Toyota's runaway cars, yes some could be tracked as carpet issues, but NASA has a throttle assembly they analyzed, with tin whiskers found to cause runaway fault event. What perplexes me, is why the brake did not have an over-ride on this system (that's where fail op systems have problems, with missing safety requirements, as it's very hard to prevent common mode design errors, starting with a paper specification).

All that said, with existing electric throttle pedals, you can control the lead foot acceleration speed, but only in a dictatorship market.

As far as efficiency:

My (now dead, damn salt) 1987 Chevrolet Sprint, exceeded 50MPG (EPA rated at 53MPG) not a hybrid, and the only electronics on the engine was the electronic points. This was a 100% Suzuki design. It weighed 1400lbs, very aerodynamic, and I would buy another one if it was still available.

There was as British car from the early 60's I think it was a Morris-Mini, that exceeded 70MPG (but that's from memory, and I have not validated that).

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#8

Re: Efficiency is a Joke

02/19/2013 5:56 PM
  • My wife's car (1971) - 4 passengers, no luggage, 30mpg.
  • My car in 2001 - 7 passengers + luggage, 55mpg.

Clearly something changed just in those 30 years.

"It might even make efficiency a priority" - ??????????

What is the point of this nonsense?

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#9
In reply to #8

Re: Efficiency is a Joke

02/20/2013 3:04 AM

I think the point of repeating nonsense often enough is that the populace begin to believe it.
It seems to work for the Bankers and our current Government.

Mr Osbourne has just issued an E-mail asking us all to repeat 100 times.
"Anyone on benefit is a scrounger. Bankers deserve their bonuses else they will take their vital services elsewhere"

See how easy it it?
Now a more advanced lesson... try this.
"All imigrants are illegal scroungers"
Right now children.. let's try it with our right arms outstretched and clicking our heels.
Del
(Sorry... little bit of politics creeping in there)

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#10

Re: Efficiency is a Joke

02/22/2013 10:56 AM

Here in the US, the weather is terrible in most of the northern areas. And, outdoor fishing is difficult. So some people find it amusing to fish on web sites, and just see what species are running.

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#11

Re: Efficiency is a Joke

03/07/2013 3:56 PM

Efficiency is purely relative to the goal in my mind. Cheaper is another way of looking at it. Achieving a goal may be all you need to determine how efficient something is.

If I can get to work 5 minutes ahead of the starting bell 100% of the time I am efficient in managing my time. I can do that by going faster in my car.

The human body is only about 20% efficient (for a physically fit individual). I think we need to start paring down all of that inefficiency! Soylent Green, anyone?

Nature is inefficient...think of all that good hydrogen that supernovas waste!

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