250 MPG

[Mechcozmo]

I personally would like to see "tribrids" or cars with 3 energy sources.

Solar, Battery, and Gas.

The solar panels charge the battery. They aren't powerful enough to power the car on their own, but during driving and parking they can charge the battery.

The battery is used for any acceleration and charged during deceleration. The battery is used from 0-25 MPH and the gas engine supplements it from there, or if during hard acceleration, earlier. But when driving down the freeway at a constant speed, the electric motors power the car. It doesn't take much power to just keep rolling. And if the battery gets low, the gas engine is used to recharge the battery. Solar panels are always charging, remember.

Solar panels need to be more efficient for this to work, (~50%) but if they get there... this could work quite nicely.

 

[mpw]

…I had no idea Jersey taxed vehicles like that. Do you have cheaper fuel? And a 10% sales tax is obviously less than here, but a lot more than 0%...

So the question is, then, what effect did the policy have, other than making a few dealers go bust? So people bought small engined cars and/or switched to public transport presumably. Is the policy deemed a success…

I suppose to be fair, here in the UK we basically are taxed by engine size, since the more fuel you use the more tax you pay. It doesn't actually seem to affect people's purchase decisions that's all; it hasn't reached punitive levels yet….

The tax was only brought in in Jan.’04 in Jan.’05 it was raised by 25%!

The dealers that went bust tout this tax as the reason for their demise but I personally don’t believe it. The dealerships were poorly managed and in financial difficulties prior to the tax, I don’t think the tax stopped people buying cars over-night, and remember last year the tax was lower.
The smaller capacity cars are generally being hit hardest sales-wise in the UK compared to larger capacity SUV’s etc. and I’d say that trend is true here also.

Have people moved to public transport at the same as this tax was introduced they introduced a new government subsidized bus service which is now the subject of a public enquiry as to the amount of subsides they say they require because of lack of demand, they cut routes etc. and their annual bus pass has managed to clock up just 7 users in it’s first year.

Our fuel has traditionally been cheaper than the UK but the gap has now closed significantly as we don’t have any real competition at the pumps as there’s no supermarket fuels just the big Pet.Co.’s Shell/Esso with a couple of Total and BP, IIRC a litre of unleaded is 94p which includes out road tax.

The new sales tax, due in a couple of years, will be added in addition to everything including new cars and fuel. You also have to take into account that while we are NOT in the UK in practice what goes there goes here so we import UK daily papers watch BBC1&2 get BBC Radio etc. and while we have Marks & Spencer they charge a 5% premium on their food to which this new sales tax will be added. Most of the UK high street shops are here and sell their goods at the same price as the UK regardless of UK VAT not being applicable these too will have sales tax in addition.

So while the tax at 10% is lower than the UK 17.5% it’ll hit us hard on things like food, papers, books, medicines and children’s clothes which are zero rated in the UK.

 

[Wrock]

I know a couple people have already mentioned this, but why hasn't there been a bigger push for the bio-diesels? A number of Trucking companies are already switching over, and this technology has been around since the 70s. I remember seeing a segment on tv back in the early 80s where they had this little datsun beater, and they were pouring cooking grease from a McDonald's fryer into it.

 

[dops7107]

I know a couple people have already mentioned this, but why hasn't there been a bigger push for the bio-diesels?

I don't know, it's a good question. There is limited use here in the UK, every so often you see something on the telly about some entrepreneur going around to pubs and chippies asking for their oil. In fact, you don't need to do anything to the engine, the oil just needs to be filtered and mixed with diesel. Of course, anyone wanting to adopt the practice is immediately hindered by the government insisting on taxing the oil as soon as you decide to use it for fuel. I should think people get away with it for a while, because it's half price even if you buy it from the supermarket (and free if you go to your local restaurant!)

 

[cslewis]

I love the guy who doesn't quite understand the various complications with hydrogenpower...

sigh....


dieoff.org

I can't wait.

Who, me?

I can see you're one of the 'dieoff crowd', the members of which have some deeply-held belief that when oil starts getting rarer and more expensive we'll all keel over and die....

Human beings adapt. I'm sure we'll survive, just with a 1830's or 1840's standard of living if we fail to find some other way to make energy.

 

[-hh]

I couldn't let this go.

Neither can I. There's a lot of snake oil in this field right now.

Batteries from all hybrid car makers are designed for the useful life of the car. In tests, Toyota has found that cars run for 150,000 miles still show no signs of degredation in the batteries.

The statistic is irrelevent if you're not taking a holistic view of the total product lifecycle, and this has exactly been my point all along.

The holistic lifecycle view is that the battery is going to wear out eventually. Similarly, at this 'eventual' point, its not going to be a free replacement, because it will be out of the OEM's Warrenty period. As such, to return the vehicle to service will incur a non-zero cost.

For example, Honda warranties for 80K miles, and per a second URL link to the one you provided, "At current prices, Honda would charge out-of-warranty owners about $3,000 to replace the 63-pound Panasonic battery..."

If for sake of arguement we define 'life of car' as twice the warrenty mileage - roughly 150K miles - then a simple linear amortization of that $3K battery replacement cost is $3K/150K miles, or 2 cents per mile.

For the 3 cents/mile Toyota value I mentioned, it doesn't matter if we're talking about a $3000 battery pack that lasts 100K miles, or a $4500 battery pack that lasts 150K miles, or a $6000 battery pack that lasts 200K miles because for a linear "cost per mile" amortization, the mathamatics come out exactly the same.

The bottom line here is that as a professional in the field of Engineering, I know that I can make all sorts of rosy-sounding claims, especially when I put technical loophole escape hatches in them.

FWIW, it also doesn't matter if its 2 cents/mile or 3 cents/mile anyway, because the holistic view is that in most cases, this is really going to be charged against the resale value of the vehicle, just like worn out tires. So instead of the trade-in being worth 10K, its theoretical market value is going to be whatever the vehicle is worth, adjusted by the incrementallly reduced life of its subcomponent systems....tires, battery pack, worn seats, etc, etc.

In other words, the inclusion of the battery pack in a hybrid is simply one more subcomponent factor that will influence the end-to-end operating costs of the vehicle ... and BTW, purely from a "parts count" engineering perspective, because a hybrid is more complex than a conventional ICE, it will always be less reliable and have higher repair costs across its lifecycle too.

This will also be taken into account in the vehicle's residual resale value too.

Also regarding disposal of batterys...

You hopefully noticed that I did provide that particular credit.

Early electric cars were everything that is summed up in that quote. They didn't sell, and what is worse, they gave electric vehicles a very bad image. With modern technology we have electric car prototypes that overcome all of these problems. You can get 80% charge in about the time it takes to refuel a hummer. You can drive 400 miles before needing to recharge. And you can go 0-to-60 in times comparable to your typical muscle car. But electric cars have an image problem, so they are not put into manufacture.

Electric cars have more than merely an image problem: to gain the benefits you list above (particularly the fast-refuel) requires a profound cash investment into our fuel supply infrastructure because of the change in energy medium....and the highly touted "Hydrogen Economy" has the same support/logistics marketplace barrier as well.

Due to the pragmatic investment perspective, we're going to probably stick with a liquid-based fuel for the forseeable future.

Thought you guys would want to see this too...a solar assisted hybrid.

Based on 2m^2 and theoretically being able to "go about 8 km each day on just the sun’s energy" (from the article), this would suggest that you could commute to/from work based on sunpower alone if you live no more than 4km from work. 4km is 2.5 miles, and with the preexisting constraint that this assumes a "sunny day" for purposed of energy collection, a motor scooter would probably be a better idea, if for no other reason than that a differential cost of $20K for the scooter vs. the solar vehicle, invested at 2% interest would buy $400 worth of fuel per year 'forever', which means that the scooter's break-even would be at ~44mpg, which is very achievable.

What I would really like to see in the short term is biodiesel/electric hybrid cars on the market.

In 2007, we'll have ultralow sulfer diesel, which will be efficiency-wise very competitive to current gas/hybrids, and it will be sufficiently convenient and "turn key" to compete with the status-quo.

I do know that some of the European automakers have looked at diesel/hybrids, including ultra-insulated engines, and the technology leap there is minimal...the biggest hurdle will be the biases of the US consumer against diesel, so d/h's are IMO fairly unlikely to hit the US marketplace until '09 or '10. Of course, perhaps by then, the diesel-based fuel cell research I saw in MA five years ago might be a bit more mature, too...that's the necessary technology to get the parts count down to that which will be competitive with the ICE for purposes of long term reliability and competitive cost-per-mile after it has been fully burdened with all relevent operating costs (not just fuel).


-hh

 

[-hh]

I know a couple people have already mentioned this, but why hasn't there been a bigger push for the bio-diesels?

For the same reason that some people have converted their homes from #2 Home Heating Oil to Natural Gas, despite the higher cost-per-BTU...

...in a word, its called "convenience".

Suffice to say that if you've never gotten a load of cheap fuel oil ... that was cheap because it was summer mix with a high wax content ... to then have an early season cold snap to +5 F turn it all into Jelly, the "fix" is either a $75 service call which won't really solve the problem, or to buy and schlep a couple of 5 gallon cans of kerosene to re-liquify that wax.

There's few things in life more pleasurable than lifting a 45 gallon can of sub-zero kerosene to head-height to your fill stem, only to miss with the first half-gallon and dump it down the front of your winter jacket and into the crotch of your nice and absorbant cotton blue jeans.

YMMV, but I'm loathe to be tied down to drive a "McDonalds frier" route just to get fuel cheap. I'll let the kids in college do that kind of fun.


-hh

 

[aloofman]

I know a couple people have already mentioned this, but why hasn't there been a bigger push for the bio-diesels? A number of Trucking companies are already switching over, and this technology has been around since the 70s. I remember seeing a segment on tv back in the early 80s where they had this little datsun beater, and they were pouring cooking grease from a McDonald's fryer into it.

There has been an increase in biodiesel use in the U.S. and there's more interest in the idea. But there are a lot of complications. It's really only worth it for people who can process biological waste (farm clippings, etc.) very close by and use it locally. If it has to be transported any significant distance to the place where it's used, the cost benefit vanishes. And depending on what fuels are burned to grow, transport, or process it, it may pollute more than it's worth.

Growing corn or other crops for use as biodiesel is also not cost effective, similar to the ethanol craze, which is just a handout to farmers with little environmental benefit.

 

[aloofman]

Not in equal amounts, no matter the party you happen to follow. I remember Clinton pushed hard for raising the average MPG in cars in America over 10-20 years. He got shot down by the GOP house, which was drowned by lobbyists. Also, he wanted tax breaks for companies that bought fuel efficient cars. That too was shot down... and as a matter of fact Bush and the GOP controlled house give tax breaks for buying a Hummer or other gas-guzzlers. Check it out. No, really... check it out. When you do, you can tell me where the good for US is that they purport to exude.

Your memory is faulty. It was a bipartisan group of congressman from auto-producing districts that killed the proposal to increase CAFE standards, not the GOP. Quite a few Democrats in Washington drive big SUVs. Check out the parking lot on Capitol Hill.

Also remember that it was not the GOP that rejected the Kyoto Treaty during the Clinton administration. The Senate rejected it 97-0. Not a single Democrat voted for it either. The idea that Bush is the one holding it back is ridiculous. It's the lawmakers around the country that have been bought and paid for by oil interests and big industry that won't let it happen. Now whether Kyoto will actually do much of anything is another subject....

 

[aloofman]

My guess as to why gas is cheaper in the US is because of supply and demand. You can't get by in America without a car (unless you live your entire life in NY ) so everyone needs a car. Sure, lots of people in Europe have cars, but public transportation/biking/walking is so much more common there then it is in the US...

Gas is cheaper in the U.S. because we don't tax it very much. In Europe gasoline is kept artificially high to encourage conservation, a policy agreed on decades ago because Europe had fewer oil resources than the U.S. did. (That's also why France is the world leader in nuclear power.) Almost any real proposal to conserve oil in the U.S. has to include raising taxes on gasoline, but this is a politically difficult feat.

 

[aloofman]

Maybe it about time you copied the rest of the world and actualy made efficient cars, i.e. a german engineered 3litre V8 will give you a lot more horses and healthier pockets thar an american designed one, plus your speed limits so slow (in places, 55 on some highways, Geez we got 30 in town, 50 on single track(thats 1 lane for both directions Not each) 60 on single caridge wars (1 lane each) and 70 on everything else) heck we have some roads with no speed limits (isle of mann) and still bomb arroung the roads at dangerourly high speeds in 1.0-2.0 Litre hatch backs that weigh less thal a small heard of obese elephants. Americas "drive" (loosest sence of the word) for economic cars seems at best half assed. i mean not signing up for kyoto, lack of diesel cars, and some cars where fuel economy is measured in Gallons per mile.
Go green!!!

I'm with you on most of that, but not this paragraph. Higher speeds use MORE gasoline, not less, especially over 60 mph, when wind resistance drags down mileage of any car regardless of its engine size or efficiency. Slower speed limits, as silly and ineffective as they usually are, save gasoline. That's why the U.S. lowered most highways to 55 mph in the 1970s. It was a stupid idea for all other reasons, but it DID conserve gasoline.

I think Kyoto specifically won't do much of anything for reducing greenhouse gases. It's the lack of interest in participating in conservation measures that's the bigger problem.

There's not a single production car sold in the United States whose mileage is measured in gallons per mile. I'm assuming you were exaggerating for effect, but it was mixed in with otherwise rational comments, so I felt like I had to mention it.

Diesel fuel is more common in Europe for one reason only: it's taxed less. People in the European countries that don't give this tax advantage (like Switzerland) aren't nearly as interested in diesel cars. Whether that's a good policy or not is debatable, but diesel is not popular in Europe because the people demand it. Having said that, diesel is very unpopular here for other reasons. The Big Three's attempts to build diesel cars in the late 1970s and early '80s were a big failure. Even though today's diesels are far superior to those of 25 years ago (in pretty much every way), the American public is soured on the idea and it will take a lot of PR to change their minds.

 

[Mechcozmo]

<-------------------------

(That's also why France is the world leader in nuclear power.)

French people?
Nuclear power?
Same sentence?
Oh, dear.

 

[dops7107]

If anybody has an hour to burn (no pun intended ), listen to this:

http://www.netcastdaily.com/broadcast/fsn2005-0806-2.mp3

It's Matthew Simmons being interviewed along the subject lines of his new book, "Twilight in the Desert: The Coming Saudi Oil Shock and the World Economy". Basically, there's a pretty big shock in store for us, considering that economists around the world have been overly optmistic regarding our oil supplies.

Think about this, to steal his analogy: a pint of oil costs 18 cents. Name me another liquid for sale as cheap as that (and tap water doesn't count). Frankly, I hink it's amazing just how much work you can get out of a litre of petrol/gasoline.

 

[-hh]

Diesel fuel is more common in Europe for one reason only: it's taxed less.

Its not just fuel cost, for the metric of significance is the cost per mile. This metric takes into account both lower fuel costs (where applicable) and higher MPG (always applicable).

Having said that, diesel is very unpopular here for other reasons. The Big Three's attempts to build diesel cars in the late 1970s and early '80s were a big failure.

That's because from an engineering standpoint, the Big 3's designs stank to high heaven and the net result was that they produced lousy and unreliable products. Compound that with the lack of a clean diesel due to trucking interests (including winter jelling) and you get most of the remaining pieces of the puzzle.

Even though today's diesels are far superior to those of 25 years ago (in pretty much every way), the American public is soured on the idea and it will take a lot of PR to change their minds.

The 'Big 3' has soured American buyers to a lot of things, through poor product execution. On the diesel front, reportedly, VW has been doing quite well with their TDI sales for the past three years...despite past marketplace poisoning.

Cynically, I think its mostly been because it has been Honda & Toyota that has lead the product introduction of Hybrids insofar as to why US Consumers have accepted them to date - - - and yes, that's a pretty damning statement about the technical prowess of the US Big 3, as evidenced by the products that they sell the public.


-hh

 

[-hh]

Gas is cheaper in the U.S. because we don't tax it very much. In Europe gasoline is kept artificially high to encourage conservation, a policy agreed on decades ago because Europe had fewer oil resources than the U.S. did. (That's also why France is the world leader in nuclear power.) Almost any real proposal to conserve oil in the U.S. has to include raising taxes on gasoline, but this is a politically difficult feat.

All true, although part of the motive for the higher tax rate in Europe is to help pay for the costs of their excellent mass transit systems.

And France's lead in nuclear power is partly due to Jimmy Carter's killing of the breeder reactor program in the USA before 1980...which if we would have pursued, would have reduced a lot of our nuclear "waste" problem through material reprocessing (aka recycling), as well as allowing us to shut down some of our military reactors of highly questionable environmental cleanliness.


-hh

 

[aloofman]

All true, although part of the motive for the higher tax rate in Europe is to help pay for the costs of their excellent mass transit systems.

-hh

Right, but it's basically a cost-benefit loop. They have to have good mass transit systems to make up for the fact that it costs more to drive a car. That kind of social engineering (for better or worse) doesn't seem to work as well in the U.S.

 

[crazytom]

A little humor.

Sorry, I just had to throw some humor into this thread:

 

[-hh]

Right, but it's basically a cost-benefit loop. They have to have good mass transit systems to make up for the fact that it costs more to drive a car. That kind of social engineering (for better or worse) doesn't seem to work as well in the U.S.

Its not really a 'social engineering' aspect in as much as its historical roots that initially predated the automobile: European cities were centers of business and commerce for literally centuries and as a result, there was a tradition of living relatively close to where you worked. With the advent of early forms of mass transit (surface trolleys, etc), the USA and Europe were still fairly similar in terms of their urban paradigms of where to live & work.

However, with the advent of WW-II, Europe had both its economy and infrastructure damaged. The net result of this was that people couldn't afford personal vehicles, and the opportunity existed to expand mass transit solutions to service the public, and it was the appropriate choice to make. Today, Europe operates on a consumption-based tax structure and utilizes fuel taxes to deliver very good (and very good value) mass transit systems.

In contrast, the 1950's postwar construction boom in the USA resulted in our Suburban Sprawl, which was then serviced by the automobile and fueled with cheap gas. Eventually exasperating this situation were things that in hindsight should have been illegal under anti-trust regulations, such as the automakers being able to buy up the mass transit companies in the Southern California area so that they could shut them down to increase their sales of automobiles.

The net result of all of that today is that for much of the USA, we have decentralized households who work in decentralized businesses...a model that is difficult (if not nearly impossible) to service in a cost-effective matter with any currently known form of mass transit...basically, because there is no "Mass" to leverage to gain economy of scale. The result is an inefficient system with infrequent service that acts as a disincentive to use it.

What all of this is really saying is that in order for us to have an effective mass transit system in the USA, we need to close down all of the small "Office Parks" and consolidate them into larger centers. Similarly too for our households - - cut the suburban sprawl. This will distill and reduce the complexity of a "hub and spoke" mass transit distribution system to fewer permutations so that the remaining options are thus cost effective and can have frequent enough service to be convenient. Of course, the attitude in the USA to sacrificing elements of our lifestyles is: "okay...you first".

-hh

 

[aloofman]

In contrast, the 1950's postwar construction boom in the USA resulted in our Suburban Sprawl, which was then serviced by the automobile and fueled with cheap gas. Eventually exasperating this situation were things that in hindsight should have been illegal under anti-trust regulations, such as the automakers being able to buy up the mass transit companies in the Southern California area so that they could shut them down to increase their sales of automobiles.

What all of this is really saying is that in order for us to have an effective mass transit system in the USA, we need to close down all of the small "Office Parks" and consolidate them into larger centers. Similarly too for our households - - cut the suburban sprawl. This will distill and reduce the complexity of a "hub and spoke" mass transit distribution system to fewer permutations so that the remaining options are thus cost effective and can have frequent enough service to be convenient. Of course, the attitude in the USA to sacrificing elements of our lifestyles is: "okay...you first".

-hh

Two thoughts:

You're never going to convince people or businesses to rip up outlying property and move closer together. A better way would be something like what Portland, Oregon, has done: establish an outer perimeter beyond which large-scale development is prohibited. Infill development is encouraged and sprawl is limited, so that even if you have to occasionally move the boundary outward, it still makes the hub-and-spoke model more efficient than most American cities are today. It's especially critical considering how fast the U.S. population is growing, far higher than Western Europe, where infrastructure expansion will be much less of an issue.

The popular leftist conspiracy about the auto industry buying and killing off Southern California's transportation system was disproved long ago. While they did buy up the remnants and scrap them, this was long after the automobile had taken over Socal and the electric trolley system had fallen into disrepair and disfavor through for other reasons. There's a nostalgia for them now, but at the time the electric trolleys were disliked by many of the locals because they were owned by private companies that milked them for cash, changed schedules on a whim, and developed land along their right-of-way for profit, like the railroad robber barons of old. Since there were few grade separations at intersections at the time, once people starting buying cars, the tracks were just in drivers' way and turned the people even further against the trolley system. It was only after cars had long since conquered the Los Angeles area that the tracks and trolleys were bought out and scrapped.

Now, it's clear that automakers helped the whole process along through marketing and other tactics, and real estate moguls made sure that sprawl was the only long-term development plan that the corrupt leaders considered. There's plenty of conspiracy to go around there, and plenty of historical lessons to learn from today. But the "Ford killed L.A.'s mass transit" theory was not a major part of it.

 

[fuzzwud]

States that have deregulated energy allow consumers to buy power from different power companies. For instance, Green Moutain Energy sells power from more environmentally friendly sources such as wind and solar. So, if you want, you can choose to buy power from a company like that. You'll pay slightly higher energy costs though. At the same time, I think it is still much better to buy power that comes from a coal power plant than your car. I forget the exact number, but I recall in physics or engineering class that an internal combustible engine (ie, car) is only 10-15% efficient in turning gas/petrol/etc into work or force. As for comparison, power plants are much higher such as 60-80% efficient.

 

[Les Kern]

Your memory is faulty. It was a bipartisan group of congressman from auto-producing districts that killed the proposal to increase CAFE standards, not the GOP. Quite a few Democrats in Washington drive big SUVs. Check out the parking lot on Capitol Hill.

Also remember that it was not the GOP that rejected the Kyoto Treaty during the Clinton administration. The Senate rejected it 97-0. Not a single Democrat voted for it either. The idea that Bush is the one holding it back is ridiculous. It's the lawmakers around the country that have been bought and paid for by oil interests and big industry that won't let it happen. Now whether Kyoto will actually do much of anything is another subject....

Hmmm.. MAYBE I don't remember exactly... maybe I do.
I seem to recall a Kerry/Hollings amendment stripped from an energy bill that would have increased the standards... stripped by the GOP controlled senate in about 1996? Maybe I'm wrong there...
As for Kyoto...
The senate may have rejected it early in the negotiations, but Clinton stayed at the table hammering out the details, and eventually signed it, much to the consternation of the vast majority in the republican party. He knew it was somewhat flawed, but signed it saying we had to start somewhere and that global warming is real. Compare that to the current admin, who casts aside science at every opportunity.

One for you, a tie on the second?
But I am sorry I injected too much POL in this.

 

[revisionA]

Post about your fuel efficient sports car!!!

Just love this topic, and the fact that I have the enigma of sports cars:

1.8L 4 cylinder ~180 hp before cold air intake maybe 190 now
2004 Toyota Celica GTS
co-designed by kawasaki, this engine sounds like a motorcycle but a little deeper, and is supposedly one of the most efficient gas cars as far as power output. I have been bursting speed and coasting around town, because its more fun... wonder if that hurts mpg or not?

I opted for a 20+ mpg sportscar and wish manufacturers would focus on handling and acceleration over topspeed.

Heres why:

Handling - More control at any speed is better for safety.
0-60 is what people talk about, feel often and enjoy doing...
going over 100 isnt necessary, legal or good for the design of small cars... and in my little 4 banger, every .1 liters of engine equals 10 hp... that means a 5.0 liter of the same concept would produce 500 hp and require rigid composite materials (OT).

If you want some fun, get a small import sports car.

Could anyone confirm that Supercharging increases MPG?
(the reuse of engine exhaust like in a turbo, but pulleyed by the engine so there is a consistent increase of hp across the powerband (rpms))

Scxott

 

[-hh]

I have been bursting speed and coasting around town, because its more fun... wonder if that hurts mpg or not?

The coasting helps, but the bursting like takes RPM's higher, so from a "less than frugal" gear ratio perspective, it probably hurts.

I opted for a 20+ mpg sportscar and wish manufacturers would focus on handling and acceleration over topspeed.

I too prefer a horsepower-limited design over a chassis-limited one. Fortunately, many of the European (particularly German) products are of this general design philosophy. Unfortunately, the Dollar:Euro exchange rate has degraded our purchasing power by roughly 40% within the past ~2.5 years.

Could anyone confirm that Supercharging increases MPG?

I'm inclined to say no for two reasons.

The first is by the way that a SC works...it "steals" power from the crank to run the compressor, and from an overall efficiency standpoint, what it mostly does is increase the specific power (eg, power per engine displacement), which is not the same thing as improving adiabatic efficency. Since the compressor isn't frictionless and so forth, there's a net power loss in the engine's "overhead" power drain.

Second, I have a 2002 Mercedes C230K ("C-Coupe") which has a 2.3L supercharged 4cyl, and it gets a disappointing-to-me combined city/highway cycle average of around 24mpg. Granted, vehicles are getting heavier due to improved safety systems, etc, but I was really expecting it to get around 26mpg. I've had it on some longer highway runs and I don't think I've ever really broken 30mpg...it makes me miss my ancient VW Scirocco which posted as high as 37mpg highway, and was usually around 28mpg around town.

FWIW, my wife's car is fairly similar...she had a FWD 2.0L Audi 80 (w/Auto) that usually would average 28ish for her commute, but when she replaced it with an AWD 1.8t Audi A4 (w/better Auto), it lost around 4mpg. I can accept the Quattro to be responsible for part of this, but 4mpg seems a bit too much of a penalty for this factor alone, plus going from a 3 speed to a 5 speed Automatic should have also bought some of this back. As such, I'd have to blame the turbocharged motor for at least 2mpg of the efficiency decline.

-hh

 

[aloofman]

Could anyone confirm that Supercharging increases MPG?
(the reuse of engine exhaust like in a turbo, but pulleyed by the engine so there is a consistent increase of hp across the powerband (rpms))

Scxott

I don't know if there's an exact answer to this. My hunch is that a big V-8 would lose mileage when supercharged, because it's not designed for fuel economy anyway. With a small supercharged engine it seems to me that you could break even or maybe get a little better, but only if you drove it in a miserly way. Something tells me that someone who's supercharged a four-cylinder probably isn't going to be light on the gas pedal though.

 

[mpw]

....enigma of sports cars....2004 Toyota Celica GTS...

.....I have been bursting speed and coasting around town, because its more fun... wonder if that hurts mpg or not?...

...wish manufacturers would focus on handling and acceleration over topspeed.

Heres why:

Handling - More control at any speed is better for safety.
0-60 is what people talk about, feel often and enjoy doing...
going over 100 isnt necessary, legal or good for the design of small cars...

Hardly a sports car, more sports saloon.

Yes that's going to hurt MPG.

I agree.

You say you are interested in acceleration and handling over top speed but you also sound like a 'petrolhead', that's only a guess and not at all a slur.

Would you consider driving an electric vehicle and if the idea doesn't stick in your throat what would it's minimum specification be before you'd consider it, style and looks discounted?