Is the Hummer "greener" than the Prius?

Also on Airbus aircraft.

Reply to
B A R R Y
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stable-mate and *the

Top Gear is the best TV program ever in the history of everything.

Unfortunately for me, I have to download it illegally because it doesn't fly in the states.

bob z.

Reply to
bob zee

NN> Sorry, I just realized I'd actually neglected something... an Otto NN> or NN> Diesel cycle engine is at best slightly less than 30% efficient NN> while an NN> electric drivetrain can achieve 90% or more. So divide my answer by NN> a NN> factor of three to get a real number.

NN> nate

NN> (oops, I hate when I do that, try to correct someone and then get my NN> answer wrong...)

You neglected the efficiency of the electrical power generating and transmission systems. While hydro power generation is very efficient the majority of power is generated thermally by burning some sort of fuel; be it coal, gas, or nuclear. Most thermal generating plants have efficiencies ranging from about 30% to 40%. If we factor in transmission line losses, we arrive at 27 to 35 % efficiency to deliver electric power to your residence. Then after we factor in the 90% efficiency of an electric vehicle we end up with an overall efficiency not much different to a gasoline powered vehicle.

Moreover, electric power tends to be more expensive than fossil fuels.

Cheers,

Indrek Aavisto

Reply to
Indrek Aavisto

I have a lot of time for that point of view, although I wouldn't call a Civic size car that small myself.

The first manufacturer to make a hybrid car that's a bit more practical will be hard pressed to keep potential purchasers from over-running their salesrooms.

Graham

Reply to
Eeyore

It wasn't commuting though was it ?

Well, a hybrid can do 500 miles day too. It just needs to burn some fuel to do so and when it does burn that fuel it uses it more efficiently than an ICE can.

Graham

Reply to
Eeyore

accelerate > faster barely uses any more

big time since they don't waste

You don't understand that electric motors operate at high efficiency over a wide range of power outputs ?

under its own power.

It does.

My posts are based on simple scientific facts. Such as the power required to move or accelerate a vehicle, which can be readily calculated.

I know that the dumbed down world has trouble understanding or even accepting science these days, but it does provide the all the answers.

Graham

Reply to
Eeyore

I'm not neglecting it at all.

You need those just to provide acceptable acceleration.

The power required for cruising at 70 mph is a mere 30 bhp (22kW).

22kW of motors will give you asthmatic acceleration and the car will slow down on gradients so you'd probably fit ~ 45kW of motors just to cope with those two things. It would give you 0-60 in 9 seconds btw in a lightweight 1 tonne (2200 lb) body.

Fitting 45kW of motors won't increase the cruising power consumption or the average power consumption though.

Lead-acid technology is over a century old and is not relevant to a discusion about EVs.

The issue of charge and discharge rates is well understood. It's *NOT* rocket science !

Modern NiMH and Li-ion battries for high current applications address these issues.

Graham

Reply to
Eeyore

Putting on the *US* market.

Graham

Reply to
Eeyore

Not for anything critical (like flight controls) it isn't.

Graham

Reply to
Eeyore

All perfectly true. The difference being that you don't need oil and you have zero emissions where the car is actually used.

That electricity can be generated from 'green' sources too.

Really ?

My own concept EV costs only ~ 4c/mile in electricity. The larger part of the mileage cost is actually amortisation of the battery cost which brings the total to ~12c/mile.

Graham

Reply to
Eeyore

Who woulda thunk it. When I was studying to be an engineer we were taught a gallon of distilled water weighed 7.92 Lbs and gasoline 6.03 Lbs

Dixon Kemp's technical dictionary says the following:

One gallon fresh water weighs 10.01lb.; one pint 20oz. A ton of fresh water is usually taken as 36 cubic feet; a ton of salt water as 35 cubic feet. (See "Cubic Measure of Water.")

U.S. Dept. of Energy says the following

Weight of One Gallon (U.S.) of Water, Gasoline, and Ethanol

  • 1 gallon of water equals 8.33 lbs. * 1 gallon of gasoline equals 5.8 to 6.5 lbs. * 1 gallon of ethanol equals 6.59 lbs.

Source: U.S. Dept. of Energy. Fuel From Farms: a Guide to Small Scale Ethanol Production. May 1980. Page D-3.

Verified by: JT, 9/98

Disclaimer: While the Library has verified the information presented in these files in what it considers to be reliable and authoritative sources, it cannot take responsibility for nor guarantee the accuracy of the information presented.

Santa Cruz Public Libraries' Home Page

mike

Reply to
Mike Hunter

You've obviously never tried to squeeze behind the wheel of one. Even the Accord and Camry are small. I used to hit my knees on the dashboard in the passenger seat when carpooling and sitting in the passenger seat.

I felt really bad for the poor souls in the back seats.

Ugh!

Exactly!

Reply to
PerfectReign

Fascinating that a whole antique system of units is preserved only in one country in the entire developed world.

Graham

Reply to
Eeyore

I've only ever been in the situation where a knee contacted the trim with one car and that's the rather small Ford Fiesta.

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Other than that it didn't actually feel very small and was very comfortable to drive.

The only time I've suffered in the back of any car was in a Ford Escort where the back seats seemd to have no support (they felt like they were made of cardboard) and made my back ache horribly.

A Ford Granada's (large car) front seat also gave me leg ache as a result of poor thigh support.

Guess which brand of car I tend not to consider ?

I'm just amazed the auto makers don't see it.

Graham

Reply to
Eeyore

They *do* see it, or at least see that building a car that doesn't compromise anything yet is significantly more efficient than today's models would make them very, very wealthy. There's people working on it, and have been for at least a decade if not more.

The problem, which you refuse to acknowledge, is that today's state of the art does not allow a practical serial-hybrid vehicle that doesn't have significant tradeoffs in purchase price, longevity, range, performance, or a combination of the above.

nate

Reply to
Nate Nagel

So why do they keep building idiot 'technology demonstrators' that are bound to fail then ?

No series hybrid need have any trade-off in range. Let's kill that one dead for starters.

Longevity ? An electric motor will outlast any ICE. The only longevity issue for any type of EV is battery life. Expect an EV to need a new battery several times during its working life. Ultracaps used for high power bursts during acceleration and regenerative braking have effectively unlimited life AIUI. Electronics generally has virtually unlimited life.

That leaves price. Until a large manufacturer commits to building EVs (PHEVs in this case) in very large numbers, component costs will remain high. There's your chicken and egg situation.

Graham

Reply to
Eeyore

Thank you. We're proud of it too.

Reply to
Bill KB3GUN

Hey, when it's what you're taught, it's what you use. Although I wouldn't be sad if I never saw another slug in my life (calculations involving mass are so much easier in SI)

nate

Reply to
N8N

The metric system would be a whole lot easier to use, once the transition phase had been accomplished. Supposedly we (USA) were going to switch over to metrics, when? - 30-odd years ago? Then supposedly again, perhaps it was about... 20 years ago: oh, yeah, we're switching over. Some signs even popped up on the NYS Thruway, stating how many km until the next exit. Ha. No switch. (And the signs disappeared; either that, or I don't even notice them any longer!)

Cathy

>
Reply to
Cathy F.

car at say 80

Somewhere in the vicinity of 65 horsepower. That's about what the original 3-cylinder Hyundai Excel had, and that's about as fast as the Hyundai would go.

Reply to
Matthew T. Russotto

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