Prius outdone in mpg...

<div class='quotetop'>QUOTE(Texas911 @ Mar 19 2007, 07:10 AM) [snapback]408332[/snapback]</div>

Except for one thing....

That is 80 MPG per PERSON... so, in comparison a Prius, seating 5, would get about 250 MPG per PERSON.

Sorry... but planes cannot beat the efficiency of cars... due to the inherent speeds and engine designs...

 

<div class='quotetop'>QUOTE(Texas911 @ Mar 19 2007, 11:10 AM) [snapback]408332[/snapback]</div>

Why is this BS?
Claims presume plane never hits head winds, and flys 100% full ... ie; perfect world conditions. Remember how the media went Weeeee! trying to debunk the prius getting 60mpg? So the EPA took it (and other cars) up to 80mph to simulate freeway speeds, then gunned it (and other cars) from red light to red light, to simulate real world city driving ... lo & behold ... Prius EPA drops to 48mpg.

 

Jet fuel is also more expensive than 87 Oct gasoline.

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Mar 19 2007, 10:42 AM) [snapback]408352[/snapback]</div>

Jet fuel for you and me maybe, but airlines buy in bulk, the little airline I work for buys something on the order of 1.5 billion gallons a year. Its loaded on the planes by the lb. and at 6.7 lbs per gal.

TEN BILLION FIFTY MILLION lbs a year and I think they get a price break.

 

<div class='quotetop'>QUOTE(DFWPrius @ Mar 19 2007, 05:28 PM) [snapback]408605[/snapback]</div>

Can you find out how much per gallon for Jet fuel airlines are buying? $3? $5? I think Jet fuel is over 100 Octane. I should really google it.

 

Ok, I'm convinced. Now all I need is 500+ carpool, ehm, airplanepool mates for my daily commute...

 

Hi Texas911,

Most of us on Priuschat know the Prius can be outdone in MPG. We want to see the real thing though, not an artifice. The Ford and GM Diesel Hybrid prototypes from the late 90's early 2000's can beat the Prius. And these were cars designed to be revised into producable economical cars. It just did not happen.

 

Didn't the Prius Marathoners get closer to 100MPG? Hah!

 

<div class='quotetop'>QUOTE(John in LB @ Mar 19 2007, 10:14 AM) [snapback]408334[/snapback]</div>

I'm not convinced that claim holds up in an apples to apples comparison. If you took a fully loaded Prius to the cruising speed of an A380, I suspect the mileage would be far worse than the 50 MPG you're assuming it gets with 5 people.

Now ... if you could pulse and glide an A380 ...

 

And if you could get an A380 to travel on wheels on the ground, I'll bet it would get even better mileage. (don't have to expend energy keeping aloft)

Maybe someone should do some road tests. Drive a Prius and an A380 down the freeway together at the same speed, each with a full load of passengers. I'd love to see that!

 

Besides, if you really want to push the envelope - we should be talking about the Boeing 787 Dreamliner. Now that's a state of the art aircraft, promising to deliver 20% better fuel efficiency at a cruising speed of Mach 0.85

Let's not compare that to the A380 - a cattle car at best.

 

<div class='quotetop'>QUOTE(Texas911 @ Mar 19 2007, 10:10 AM) [snapback]408332[/snapback]</div>

Boeing published a figure of (as I recall) 56 passenger-miles per gallon at average US load factor (% of seats filled), for one of its 7x7 designes, might have been the 747. So, this appears ballpark.

I bring this up because I wanted to calculate how much more environmentally damaging it would be to fly to a vacation destination than to drive there, for my family of four.

The key fact is that 56 passenger-miles per gallon is the average for the entire plane. Total gallons divided by total passenger miles, at average load factor. But most of what you are using fuel for is moving is the plane, not the load.

Given that the plane is going to fly anyway whether I choose to fly or not, the question I really wanted to ask is: how much *more* fuel will the plane use, with me on it, compared to the plane, without me on it? What's my *marginal* impact on jet fuel used. (Assuming the plane has empty seats). The answer to this question would tell me how much more jet fuel is consumed due to my decision to fly. That's the right benchmark for judging my fly/drive decision in isolation.

The best answer I could come up with, based on studies of the impact that US obesity has on jet fuel usage, is that the marginal fuel use is about one-quarter of the average, for my family's weight, at the average US load factor. In other word, at the average load factor, adding one more passenger to the plane increases fuel use not by 1/56th of a gallon per mile (ie, not at 56 passenger-miles per gallon), but at about one-quarter of that rate.

The upshot is that I am roughly indifferent between flying and driving, for my family of four, from the standpoint of total fuel use. Or at least I think I am. The amount of *additional* jet fuel consumed by adding my family of four to a plane ride, for a given number of miles, is just slightly higher than the amount of *additional* gasoline consumed by driving my family of four the same number of miles.

This abstracts from the fact that jet fuel, like diesel fuel, requires more crude oil input per gallon of fuel, and produces more carbon output per gallon of fuel. (Ie, there's more stuff in a gallon of jet fuel than in a gallon of gasoline.) Ignoring that, and focusing narrowly on the impact that my one decision has on total jet fuel versus auto fuel consumption, it didn't seem to matter much whether my family of four flew or drove to our destination.

 

<div class='quotetop'>QUOTE(chogan @ Mar 20 2007, 10:33 AM) [snapback]409060[/snapback]</div>

Not quite - you forgot to take into account the "consumption" of your Prius - if you drive it on your vacation. Don't forget that manufacturing the car uses significantly more energy than the amount the car uses over its life.

Using your argument that the plane is going to be flown anyway, that penalty would not be applied to the aircraft... therefore you should fly....

 

I took pictures of the 380 yesterday at LAX That thing was enormous!

 

<div class='quotetop'>QUOTE(paulccullen @ Mar 19 2007, 10:06 PM) [snapback]408709[/snapback]</div>

Well, it's not a Prius and it's not an A380, but it's as close as you'll get.

http://www.405themovie.com/Home.asp

Fun stuff..

Dan