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The Easy Leg: Vehicle Efficiency
Peak Oil Investments I'm Putting My Money On: Part X, Improving Vehicle Efficiency
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This article came up at work today. Of course, there were the HP junkies that said nobody who liked cars would ever want to go to 1985 vehicle HP/weight levels.
Of course, I think, in other parts of the world new cars like this exist...unfortunately not here in the USA :-( |
This is what I have been telling my students for the last 5 years! We have increased efficiency drastically, but increased HP to maintain that mpg. The only problem that we have with reducing weight is the required safety equipment. Manufacturers could cut weight in creature comfort items, though, but the rewards of FE would be marred by poor sales.
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have made great strides in engine efficiency... but they have used the progress to deliver more power at the same MPG, rather than increasing MPG. Since 1985, average fuel economy has dropped 5%, while vehicle weight has risen 29% and average horsepower has increased 86%. That's what makes vehicle efficiency easy: even without further advances in engine efficiency, we could greatly increase fuel economy by just returning vehicle weight and horsepower to 1985 levels.
On so many levels this is a classic example of percentages telling a different story than the facts that exist. But I don't want to get into a huge discussion. let me just offer up two thoughts: 1. CAFE standards set different goals for trucks so the manufacturers moved to the more obvious choice and built trucks. Kinda the unintended result of government and lobby intervention. 2. I drive an 02 Infiniti Q45. The Q was introduced in 1990 and never caught on like it's competition the Lexus LS. So in late 2000, Infiniti decided to take one last bite at the upper end luxo/sport sedan market. The 2002 infiniti weighs almost 500 lbs less than the 4 other sedans that it competed with. lot's of aluminum and alloy. It also got 50 more hp than the next competitor. THey all run 4 to 4.5 liter V8s. The Q also got better mpg than all four. (not a big selling point in this bracket of vehicles) Without any major mods or hypermiling, I was getting 27mpg on 300 mile trips (epa 23) my point is that manufacturers can produce cars that are effecient and perform better. as a final thought, I am perplexed by the reference to 1985 numbers.... The mid 80's were a horrible time for cars. Pollution devices were being strapped on with little engineering and thought. that was probably the low point for effecency in american cars. There was no effecency in the use of materials either. |
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I think a gas/electric hybrid is a good solution for most middle of the road consumers who want good acceleration and good fuel economy. As the electric portion of the hybrid gets more powerful, city mpg and acceleration get better. As the gas portion gets smaller, highway economy improves.
Going hybrid may add 100-200lbs to the car, but it more than pulls its weight as you can see from the EPA city numbers. It also adds thousands of dollars to the price of the car, and we won't see hybrids become the norm until automakers have exhausted all the cheaper methods of buying MPG, some of which are also on the list in the OP. |
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Build the same thing today, with fuel injection & turbocharging, and maybe some aluminum & carbon fiber in the body, and I'll buy it. |
autoteach -
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CarloSW2 |
But my point is that the 85 engines were not optimally effecient. That is the problem with the whole article.
85 was not some magical moment in mpg nervana. I will agree that 2 cars come to mind as first steps but the rest of the industry was still behind the curve. 1. is the honda crx 2 corevette what is intesting is both of these cars were as light as possible and were FAST. Key words: Light and fast. as a byproduct, the also got good mpg. The article is take a broad swipe at numbers that include everything from crx to Ford F-350 dually trucks. As we have seen in the last year, auto manufacturers in america were not really making cars. The were making items with overinflated prices to fund 'unfunded' pensions and healthcare for retirees. Much like Greece and soon California and the US, the product was irrelevant. It was just away to redistribute wealth. The only reason car companies can't build little fun eco cars is because there is not enough margin to cover the add-on costs. It becomes frustrating when people complain about 'the good old days' and have no grasp what so ever on the outside forces that cause things to happen. When I was in college from 76-81 I said that if unions REALLY believed that their members built quality products then they should get stock options instead of additional benefits. Guess the unions were smarter than me........ |
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Take a 2000kg luxury car, pull out the electric/electronic gizmos and you save 200-400 kg. Another 100-200kg can be saved by replacing the 3.5 liter V6 with a turbocharged, aluminum block, 100hp 4-banger, and the auto trans with a manual. By now, the crumple zones have to handle 30% less momentum in a crash than in the original car, so they don't have to be so buffed up. And what about making the whole chassis out of aluminum (like the Audi A2)? Of course, things like airbags still must be present, and I don't know whether their weight can be reduced. |
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I mean if you were moving 2 tons of cargo over asphalt or 50 people it might be good, but were talking two people and maybe a handbag ;) |
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the 1985 number is carburators. it is a fantastically twisted fairy tale about injection.
I lived through it. My carbed 90hp subaru is somebody elses 180 today..injections sucking in more fuel than ever...and funny enough within 200 pounds in real weight. it is grotesque to think how stupid they got with real automobiles. they even lie and lie and lie... The heads up for me was having a 300hp v8 in the 10s at a quarter.. all of a sudden, the numbers in hp started increasing..and not doing a damn bit of difference. Wo. somebody is going mobster about fuel injection...it happened in the early 1990s. The only place I saw hold true about power increases and staying the same fuel mileage is my dads rigs.. from 290- 550+..all 5-7 mpg...and of course, that is showing its true colors with the new v8 diesels by ford and gm. cars are a hacked retarded midget wizard of oz fantasy in comparison.:eek: |
I've been through it too, and maybe I misunderstand the fuel injection comments, but I only see benefits to electronic fuel injection in comparison to carbs.
They tried to give the carburetor feedback about how far off the mark it was, and tried to work around newly created problems with gobs of vacuum lines, but it was still guesswork and clunky. Enter fuel injection. Suddenly it is easy to troubleshoot, just check for a signal, and if that looks right pop out the injector and point it in a glass and see what it does and how much it squirts. No flowbench or mojo required. No fudging with accelerator pumps or automatic chokes or other hacks of endearment. Suddenly the cars are meeting emission requirements that were not practical with a carb that now resembled a potato trying to have kids. No eyes watering as you wade through huge numbers of unburnt hydrocarbons. Heck, even an occasional clear day in LA. Now having refined the fuel delivery algorithms, direct injection is commonplace, and the throttle losses for gasoline even does not look necessary for much longer. Mixture monitoring and control is one of the things computers are pretty good at. Yah, it gets abused by the cry and push for more power, but like most problems, that is a human phenomenon. What am I missing bgd? have I misinterpreted your position or do you detest fuel injection on (current) technical grounds? |
I agree about keeping safety equipment, what I was saying was that we could not reduce the vehicle weight to early 80's weight for our subcompact market. those vehicles were seriously light (thinking japanese here).
Here is my thoughts on FI, it IS the only way for fuel efficiency. Forget the weight that it bears, HCCI engines will give you FE like you never have seen before. Just get that into a 1L or 1.5L engine and on a compact car, manual (no automanual, too heavy). For every pound you drop off the car in components, you drop weight in components. What I mean about that is lighter wheels need lighter springs, lighter car needs lighter springs. Lighter car and springs=lighter torsion bars, mounts, ball joints. Lighter seats, lighter suspension. Lighter bodywork, lighter carpet, electronics, cooling system (4 reduce engine size), reduce reduce reduce reduce If the pattern is reduction, it is a self fulfilling prophecy. Go figure. |
Unfortunately, as I tried to make clear earlier, you cant "just drop this or that" wala!!!
The companies have a dollar amount that has to pay the cost to produce a unit(not manufactureing costs). let's say it's $5000 a unit. That covers the rent, the insurance, the electricity, the marketing, pension plans, etc. There are no actual car parts in that $$$. Then they have to create a car. If we build a very light and simple car that cost 7,000 in material, then we have to mark that up so the manufacturer makes money add 1000. Now it needs a sticker price so the dealer can make money add 2000. That is a 15,000 car. I can promis you that you would not buy this car. It would be noisy, uncomfortable, lack any real response...... THe A2 is listed at 22,000. Audi is probably not making any money at the price. That is true for most car makers. THe low end of their model lines barely breakeven. It is not like the manufactures DONT want to build the ideal car. But there is more than 1/2 the price that is sitting on the design table to start with. I mentioned my 2002 Infiniti Q45. It has an aluninuum body, suspesion parts etc. At $60,000 Infiniti never made any money on the Q45 brand. I don't mean to belabor the point, but it's not that the ideas arent there. THe business model is very broken. |
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Or to take the CRX as a base, Honda sells the Fit at $15-20K MSRP. Suppose they started with the basic Fit platform, and built the lighter, quicker next-gen CRX on it. Wouldn't there be people willing to pay a $5-10K premium over the basic Fit for one? |
To get good MPG, you don't have to cut HP. However, you have to have a well-designed, efficient engine that scales to load well.
If we take generators as an example, we can see the advantage of diesel over gas in a huge way. For example, we have generator A (gas), and generator B (diesel), which are both capable of producing the same power, both turn a constant 1800 RPM, and both use 2 gallons per hour at full load. However, we see the difference in the part load consumption, where something resembling this occurs: Generator A No load - 0.6 gphGenerator B No load - 0.4 gphBasically, some engines, diesels in particular, scale fuel consumption more linearly with load. The gas engine uses 50% of it's full load fuel consumption at 1/4 load. The diesel reaches 50% of full load consumption just before 1/2 load, using only 35% of its full load consumption at 1/4 load, which is much more efficient, and a much more linear usage curve. The more linear the usage curve of an engine, the less it hurts FE to run an overpowered engine at light load, allowing a car to go fast when needed, but still return good mpg in gentle driving. My Jeep, for example, has a very non-linear consumption curve. I actually get worse mpg if I accelerate gently around town. If I get on it harder, and let it shift around 2200 or so, allowing me to get off the gas sooner, it can make the difference between 11.5 and 12.5 mpg with otherwise identical driving in the city. Of course, this doesn't work with other cars in front of me downtown, as they typically crawl up to speed so slowly the tranny shifts at 1500 - 1600 and I'm barely touching the gas at all. |
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