[smallpoxgirl]

If this has already been discussed in another thread, somebody please let me know. I came across some numbers this week that I thought were just astonishing.

Efficiency of the Ford Model T: 25 to 30 mpg. link
Average Fuel Efficiency of Cars sold in 2006: 21 mpg. link

Clearly what we've been told about newer cars being more efficient is bogus. Increasing fuel usage despite increasing vehicle efficiency is often stated as a validation of Jevon's paradox. This statistic makes me wonder if we're drawing wrong conclusions.

[dooberheim]

Don't have a link for you, but I have a 1963 Plymouth Valiant (170 ci 6 cyl - 3 spd manual) that gets 24-30 mpg. I'm making it into a light pickup - it should do a bit better that way.

Crash standards and power mania have added greatly to the weight of automobiles. Also, every auto sold today is unnecessarily powerful - a car shouldn't have to acheive 0-60 in less than 17 seconds or so. My Metro can do it in 13 seconds or so, and it is considered "underpowered". We will learn soon that simply having transportation is more important than it being quick.

DK

[Aimrehtopyh]

The model-T only had a twenty horsepower engine and a top speed of about 45mph.

.........................Model-T...'42 willys jeep....'06 chevy truck
MPG................... 25-30........13.8.....................24
Horsepower.........20..............54.....................175
torque (ft.lbs)......60?.............95.....................185
displacement (L) 2.9..............2.2.....................2.8
weight (lbs)........1300..........2400..................3300

We are without a doubt getting more torque and horsepower out of a gallon of gas these days. So our engineers haven't died off or gone to sleep, they've been hard at work making our vehicles as powerful as the EPA will allow because the market demands it.

"Additional torque and horsepower will make a car move faster." As true for an automobile marketeer as it is for an automobile engineer.

Sad but true; power is a safety feature when merging onto todays insane freeways.

edit:added comment 2nd edit:fixing my "chart"

[smallpoxgirl]

$this->bbcode_second_pass_quote('Aimrehtopyh', 'W')e are without a doubt getting more torque and horsepower out of a gallon of gas these days.

[Kingcoal]

Efficiency is a relative term. The model T could be compared to a modern econobox. The econobox will out accelerate it and achieve more than double the top speed and carry more load and finally, get better gas mileage.

The reason for the low average MPG; people prefer gas guzzlers.

[bonjaski]

my car does 52mpg with 95ps

its up to you, what you want

[dukey]

the average mpg of cars in the uk is 38

Although 1 US gallon = 0.83 Imperial gallons

What's that 32mpg in US gallons ? Something like that ..

Even so, our average fuel economy is a LOT better than you yanks. If you want to know why .. just look at the cars we drive.

http://www.cambridgecarandvanrental.co. ... people.htm

[drew]

Sorry Smallpox girl, I dont want to rain on your parade but what you are talking about is relative fuel efficiency of vehicles, not the fuel efficiency of the engine itself. As someone said, the engineers have not been sitting on their duffs all these years.

Engine fuel efficiency is typically measured as brake specific fuel consumption (bsfc) which is a measure of how much fuel (by weight) is required to produce 1 horsepower for 1 hour. This measure of efficiency has improved a great deal over the years although the upper limits are somewhat fixed. These limits are around .4 for diesels and ~ .5 for gasoline.

The biggest improvement in bsfc has been the operating range of the engine; previously maximum efficiency could only be acheived in narrow operating ranges. In other words modern engines are more efficent over a broader range of driving conditions than their predecessors.

One of the reasons the diesel gets better mileage is the fact its fuel is 25% denser than gasoline. This directly affects bsfc. since diesel fuel has more caloric energy by weight than gasoline. The upper limits of efficiency are probably near at hand unless some new materials are designed and used. Simply put, an awful lot of energy is wasted in cooling down the engine, and a lot of heat simply escapes in the tail pipe.

Your issue is mine btw; why do people feel the need to commute to work in 275 hp, 5000 lb SUV's?

It is a problem caused by unnecessary horepower and weight, not engine fuel efficiency, sorry.

Drew

[dukey]

$this->bbcode_second_pass_quote('', 'Y')our issue is mine btw; why do people feel the need to commute to work in 275 hp, 5000 lb SUV's?

It is a problem caused by unnecessary horepower and weight, not engine fuel efficiency, sorry.

[MonteQuest]

$this->bbcode_second_pass_quote('smallpoxgirl', ' ')Clearly what we've been told about newer cars being more efficient is bogus. Increasing fuel usage despite increasing vehicle efficiency is often stated as a validation of Jevon's paradox. This statistic makes me wonder if we're drawing wrong conclusions.

[smallpoxgirl]

$this->bbcode_second_pass_quote('drew', 'S')orry Smallpox girl, I dont want to rain on your parade but what you are talking about is relative fuel efficiency of vehicles, not the fuel efficiency of the engine itself. As someone said, the engineers have not been sitting on their duffs all these years.

[bonjaski]

$this->bbcode_second_pass_quote('drew', '
')Your issue is mine btw; why do people feel the need to commute to work in 275 hp, 5000 lb SUV's?

Drew

[Frank]

You can get good data on fuel consumption, efficiency, etc. by looking on various EPA pages or searching on CAFE (Corporate Average Fuel Economy). It's true that current cars get slightly less mileage than 20 years ago but that's market driven (don't get me started on how Congress has refused to increase the CAFE standards since 1985 or how the tests do not reflect real-world driving or how there's no teeth in the law).

It is simplistic, however, to compare old-fashioned cars to what's on the road today. Average speed was much lower, there were absolutely no emission controls and no safety equipment.

There's a lot of vehicles out there that get great fuel economy, but as someone mentioned, if you're driving 10X further - does it really matter? Until there's a real crunch or we start taxing carbon emissions not much will change.

[MonteQuest]

$this->bbcode_second_pass_quote('smallpoxgirl', ' ')I'm pretty familiar with the graph. The problem is that the graph starts in 1950. If you extended it back further to the left, you would find that fuel efficiency, instead of being an upslope would be V shaped. (high at the begining, low in the middle, coming back up towards the end.) Maybe it's legit to just cherry pick out '75 to '90 and say that fuel efficiency went up and so did fuel consumption. The picture would be the opposite at the other end of that graph. (Fuel efficiency falling and fuel usage going up) Maybe the two are unrelated.

[drew]

$this->bbcode_second_pass_quote('smallpoxgirl', ' ')My point was that its pretty shocking that they have managed to design the rest of the car so wastefully that the fuel efficiency has actually fallen despite all the improvements in the engine.

[smallpoxgirl]

$this->bbcode_second_pass_quote('MonteQuest', '')$this->bbcode_second_pass_quote('', 'I') claimed that they were not working on making cars more efficient. If they were, cars would obviously get more than 21 mpg because cars got 25+ mpg back in the 1920s.

[smallpoxgirl]

$this->bbcode_second_pass_quote('drew', 'B')ut, as I said earlier, when we compare apples to apples fuel economy is actually up.

[drew]

You are arguing for the sake of arguing, and aren't winning. What do you define as a starting point? The Model T? Fine, it gets 24 mpg, and carried 4 people. The two corrolas I cited get 30 and 42 mpg, and carry 4, or maybe 5 people in a pinch. How is that not improvement? Similarly, do you not think truck fuel economy has not improved since trucks were invented? Of course it has. I threw some real numbers at you to prove my point, what else needs to be said?

Drew

[MonteQuest]

$this->bbcode_second_pass_quote('smallpoxgirl', ' ') Similarly, if the auto manufacturers had been serious about increasing efficiency, clearly they could have made vehicles that were more efficient than the Model T.

[MonteQuest]

$this->bbcode_second_pass_quote('smallpoxgirl', ' ') If you want to build a more efficient car, clearly weight, horsepower, complexity, are all things that you may have to limit. If you are serious about designing a more efficient car, it's probably going to have to be lighter, less powerful, etc.