Real Way to Save Oil..............

[samclem]

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Originally Posted by eridanus Yes, a real car the way Americans drive them. That's why I wrote "BTU/passenger mile." http://www.bts.gov/publications/nati...ble_04_20.html It turns out that flying has been more fuel efficient than driving in 2003 and 2004, breaking a 35 year trend. Who knows why this is? CAFE is down, winglets, older planes retiring?

Okay, we agree that airplanes used fewer BTUs per passenger mile than cars did for the last two years figures were available.

But, the info you provided on BTU/mile seemed different enough from my WAG ealier that I took another look at my math--sure enough, I'd inserted an extra zero. So, the fuel burn (in BTU) per passenger mile for cars and airliners is about the same. That is still fairly amazing, given that the majority of fuel burned by a car at highway speeds is used to overcome air drag, and that air drag is proportional to airspeed squared. With a car moving at 60 mph and a jetliner is moving at approx 500 mph, the difference of the squares is a lot, and it is impressiive that the airliners can get the job done at approx the same btu/passenger mile as a car. I'd guess this is mostly attributable to the thinner air at altitude and less frontal/wetted area per unit volume for the airplane.

Back to the info in your link: I'm surprised that the airlines used more BTU per passenger mile in international service than in domestic service. Bigger airplanes and a higher percentage of time at higher altitudes should have given the international flights an edge. Maybe they fly with a larger percentage of empty seats?

[cute fuzzy bunny]

I think everyone should drive a 727, yet long to own a 747 while making catty remarks about 747 drivers.

[ERD50]

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Originally Posted by FinanceDude If there was a way to increase gas mileage 50% in semis, US oil consumption would drop 10-15% just from that...........

I would think the transportation industry is already plenty motivated to achieve this - just pure economics, no 'green' needed.

I also don't think there is any silver bullet for trucks like this - 50% would be a HUGE number. That reminds me of 200mpg carburetor and cow magnets on the fuel line talk. As others pointed out, it is amazing that these trucks can get the mileage they do considering their size and weight.

-ERD50

[FinanceDude]

Quote:

Originally Posted by ERD50 I would think the transportation industry is already plenty motivated to achieve this - just pure economics, no 'green' needed. I also don't think there is any silver bullet for trucks like this - 50% would be a HUGE number. That reminds me of 200mpg carburetor and cow magnets on the fuel line talk. As others pointed out, it is amazing that these trucks can get the mileage they do considering their size and weight. -ERD50

Coming your way in LESS than a YEAR...........Hybrid GMC and Chevy Suburbans and Yukons that get 25% better fuel economy than now.........up to 28 highway for the 2wd ones..............

[ERD50]

Quote:

Originally Posted by FinanceDude Coming your way in LESS than a YEAR...........Hybrid GMC and Chevy Suburbans and Yukons that get 25% better fuel economy than now.........up to 28 highway for the 2wd ones..............

But that is for a small truck, not for a semi with a huge payload that spends 90% of it's time cruising at highway speeds. A hybrid can actually hurt performance in that case (drag along more weight in the battery and electric motor that go unused 95% of the time).

In a hybrid, the motor/battery help to provide power at acceleration, and recover it while braking. For stop/go driving it is great (but still expensive). But for 90% 'go' driving, it is mostly dead weight.

Hybrid cars also get better highway mileage, because, due to the balance of stop/go, the ICE is smaller (does not need to be so big to provide acceleration), so that smaller ICE is more efficient at highway speeds - less throttle drag. But, diesel engines don't have that same drag. They have no air throttle, the injectors control combustion, one of the reasons that they are much more efficient.

But, technology aside, just use some logic. A big rig is owned by for-profit companies, it gobbles expensive fuel at single digit mpg rates, and travels over 100,000 miles a year. If it was cost effective, wouldn't the transportation companies be buying hybrid semi trucks? And wouldn't the manufacturers jump at the chance to sell them a more expensive product?

My guess is simple - the numbers don't work. In fact, in most cases, the numbers don't work for the hybrids cars sold today. People buy them to feel good about using less fuel and polluting less, which is nice, but the economics are seldom in their favor - unless they drive lots and lots of miles. And hope the batteries do not need replacing.

-ERD50

[Brat]

Let's admit it, oil is cost efficient and because it is a fluid it is easy to deploy. If availability decreases, and the price increases, over years technology will adapt. Our real risk is sudden disruptions in supply.

[Telly]

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Originally Posted by Brat Let's admit it, oil is cost efficient and because it is a fluid it is easy to deploy. If availability decreases, and the price increases, over years technology will adapt. Our real risk is sudden disruptions in supply.

I can't argue with that, Brat.

But I sometimes do go off on a flight of fancy about how nice it would be if we were not dependent on the mid-east, and could just let them all go at it and stew in their own juices (my bets would be on the continuing survival of the Israelis!)

[ERD50]

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Originally Posted by Telly But I sometimes do go off on a flight of fancy about how nice it would be if we were not dependent on the mid-east, and could just let them all go at it and stew in their own juices (my bets would be on the continuing survival of the Israelis!)

Well, as it was pointed out to me in a recent thread, oil is a fungible commodity. If we reduced our oil consumption by 12% or so (the % of the oil we use that comes from the middle east), the rest of the world would keep buying from them. We would drive up the price of non-middle-east oil. I'd guess those countries would resell us the oil they bought from the middle-east. What are you going to do - ask for a DNA test?

Now, get the whole world to stop using oil, that could do something. I wonder what the result would be?

-ERD50

[lazygood4nothinbum]

if you have money to burn this will help save a little oil.

[Brat]

It is interesting to me that geothermal isn't explored more for power generation.

[Nords]

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Originally Posted by Brat It is interesting to me that geothermal isn't explored more for power generation.

Around here the venting of hydrogen sulfide is a real safety issue, to say nothing of the livability.