Good post no-wheels, but you didn't mention what must be one of the biggest advantages of these cars, being the fact that they will produce much less noise and smog in the cities.
Your point about the life expectancy of cars is an excellent one though, and is something that usually goes ignored.
I am sure that battery technology will come on in leaps and bounds. The size of my current mobile compared to the first generation models is a good example of this. This is the key I think, if they can make a battery small enough and cheap enough they will be in business.
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Your mobile may not be a good analagy, battery technology has improved but a lot of development has also gone into reducing the power required in the first place. This is fine in mobile phone technology but it's a bit more difficult reducing power requirements in a car, ensuring the car meets current legislation and making it drive well.
AS NoWheels implied, automotive hybrid technology is an "in thing" at present but it's more about politics (especially over the pond) than efficiency and green credibility.
Ultimately, it'll be hydrogen fuelled vehicles with the hydrogen created by nuclear fuelled electricity.
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Ultimately, it'll be hydrogen fuelled vehicles with the hydrogen created by nuclear fuelled electricity.
Ultimately perhaps, but not tomorrow I think.
And NoWheels, why is an improvement in engine efficiency a 'marginal' advantage? Many a mickle makes a muckle. A fifties driver would find the performance/economy ratio of modern cars astonishing, and the process is still continuing. Yesterday's shock-horror global warming story should remind us that we need to care about this, and that the politicos are certainly going to use it as an excuse to torture us a bit more.
My guess is that before we get hydrogen fuel cells the 'hybrid' car will have ceased to be regarded as a hybrid and will seem normal. Roll on this Citroen thing.
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And NoWheels, why is an improvement in engine efficiency a 'marginal' advantage?
Any efficiency gain needs to considered not just on the narrow measure of how power you get out of a galon of fuel (the marginal gain), but also on what has to be done to achieve it.
A small increase in engine efficiency sounds like it's something to be welcomed - evey little helps etc-- but if it comes at the cost of shortening the car's life, then its overall efect will be negative.
Many a mickle makes a muckle. A fifties driver would find the performance/economy ratio of modern cars astonishing, and the process is still continuing.
It's interesting to look more closely at that -- there's a lot more to eneergy efficiency than simly measuring power-fuel ratios.
Engines have been getting more efficient, but at the same time the size and weight of the vehicles they propel has been increasing. Part of the efficiency gain is simply being used up by creating new inefficiencies :(
We are aleady at the point where the complexity of the engines is leading to an otherwise serviceable vehicle being scrapped because the cost of repair is too high. Cars last a lot longer than they did in the 60s or 70s, but there is a balance to be struck between increased operating efficiency and the inefficiency of shorter service lives.
I don't know where we are on that curve, but the huge extra complexity of hyrbrids means that bit of the equation needs careful examination.
Yesterday's shock-horror global warming story should remind us that we need to care about this, and that the politicos are certainly going to use it as an excuse to torture us a bit more.
Actually, the message of yesterday's news was that marginal improvements are likely to be woefully inadequate -- we need much much bigger reductions in CO2 emissions. Hybrids may end up only diverting resorces from developing the much more radical solutions which may be needed.
My guess is that before we get hydrogen fuel cells the 'hybrid' car will have ceased to be regarded as a hybrid and will seem normal. Roll on this Citroen thing.
Let's see how the promised mpg translates into real-life gains. Reports of the Prius suggest that the gains are not as big as promised.
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>> And NoWheels, why is an improvement in engine efficiency a 'marginal' >> advantage? Any efficiency gain needs to considered not just on the narrow measure of how power you get out of a galon of fuel (the marginal gain), but also on what has to be done to achieve it. A small increase in engine efficiency sounds like it's something to be welcomed - evey little helps etc-- but if it comes at the cost of shortening the car's life, then its overall efect will be negative.
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Actually many if not all cars made these days live quite a long time if properly looked after. There were cars in the 60s, 70s and 80s that used to rot on the forecourts.
Engines have been getting more efficient, but at the same time the size and weight of the vehicles they propel has been increasing. Part of the efficiency gain is simply being used up by creating new inefficiencies :(
I'm with you there, to the extent that what you say is true. Actually a lot of modern cars are lighter than their predecessors despite all the kit. A lot of it is just lightweight electronic stuff.
We are aleady at the point where the complexity of the engines is leading to an otherwise serviceable vehicle being scrapped because the cost of repair is too high. Cars last a lot longer than they did in the 60s or 70s, but there is a balance to be struck between increased operating efficiency and the inefficiency of shorter service lives.
Here too. But although it seems sad to old-fashioned mend-and-darn types like us, this very good quality espensive to repair throwaway stuff is the style of the moment. Ideally engines (and let us not forget the rest of the jalopy) would be as good as they are now and repairable. Indeed Aprilia may tell us that they are if you know what you're doing. I don't know where we are on that curve, but the huge extra complexity of hyrbrids means that bit of the equation needs careful examination.
What are you worried about? complexity isn't a problem. Materials are. Is it rare earths panic now?
>Actually, the message of yesterday's news was that marginal improvements are likely to be woefully inadequate -- we need much much bigger reductions in CO2 emissions. Hybrids may end up only diverting resorces from developing the much more radical solutions which may be needed.
I repeat: many a mickle makes a muckle. A mickle may not be worth having but a muckle is.
Let's see how the promised mpg translates into real-life gains. Reports of the Prius suggest that the gains are not as big as promised.
As usual. But still big.
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>> I don't know where we are on that curve, but the >> huge extra complexity of hyrbrids means that bit of the >> equation needs careful examination. What are you worried about? complexity isn't a problem. Materials are. Is it rare earths panic now?
Complexity of itself isn't an energy or pollution issue, but vehicle-life-shortening complexity is.
Aside from any raw materials issues, there's the simple problem that complexity brings forward the point at which repair becomes uneconomic. So the vehicle is scrapped and a new one made, with a significant energy cost.
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Good post no-wheels, but you didn't mention what must be one of the biggest advantages of these cars, being the fact that they will produce much less noise and smog in the cities.
The noise factor probably helps, but in terms of smog they really only displace it: all their energy ultimately comes from burning oil, and the overall gain may only be the marginal benefit of increased engine efficiency.
Even the degree of displacement depends on the balance of usage -- a hybrid used solely in the city will still produce all its smog there.
An electric-only vehicle (whether by battery or hydrogen, both are just electricity storage) will have a much better displacement effect than the hybrid.
A super-light combustion car such as a petrol-only Honda Insight would probably come out ahead of the hybrid on smog.
Your point about the life expectancy of cars is an excellent one though, and is something that usually goes ignored.
Thanks :)
I am sure that battery technology will come on in leaps and bounds.
Maybe, maybe not. Small-scale battery technology has seen useful improvements, tho still relatively small, but bigger capacity batteries have seen only marginal improvements. Some physicists argue that batteries are a static technology with litle room for significant improvement without a breakthrough shift to a wholly new technlogy.
If that happens, the prospects for hybrids may change, but I've never seen anything to suggst that such a breakthrough is anywhere on the horizon.
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Are the engines in hybrids more efficent? I don't think they are.
Its the braking system that captures wasted energy that gives the efficency.
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Probably, but as I said above, ideal power and torque curves for engines that drive generators at near constant speed might lead to different engine designs. For instance, a 3-cylinder engine, which might be inflexible and juddery in a manual car, might be fine when it powers a generator at 3000 rpm and doesn't transmit any torsional vibration through a mechanical drivetrain.
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Doesn't the Prius use an Atkinson cycle engine that is very fuel-efficient at certain fixed speeds, but would be useless as the only power source for a car?
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Unless I'm mistaken, the Prius also uses the engine as a traction source, not just to generate electricity. So, as with all hybrids, the overall fuel ecenomy is limited by the what the engine consumes when it is powering the wheels and charging the battery.
It's worth remembering that hybrids weren't originally developed with fuel economy in mind, but as a solution to the ZEV (Zero Emissions Vehicle) regulations that some American states were considering introducing for cities in the 90s. Hybrids produce no emissions whilst running from the battery only.
Auto Motor and Sport in Germany tested petrol, diesel and hybrid cars against each several months ago and found the diesel was overall easily the most economical whereas the hybrid showed marginal improvements over the basic petrol. They attributed this improvement to the hybrid having a smaller capacity engine than the petrol powered version and to people adjusting their driving style to fit the characteristics of the hybrid powertrain, which fits in with my personal experience of people I know in the USA who own them.
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I think it was an engineer at GM of all companies who pointed out the major problem with diesel hybrids:
Diesel = expensive
Hybrid = expensive
Diesel hybrid = very expensive
I suspect purchase price will prevent mass take up of this technological blind alley.
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I think it was an engineer at GM of all companies who pointed out the major problem with diesel hybrids: Diesel = expensive Hybrid = expensive Diesel hybrid = very expensive I suspect purchase price will prevent mass take up of this technological blind alley.
Point taken. Like many car enthusiasts I am torn between simpicity, which is obviously good, and complexity, which is by nature fascinating. It has been pointed out elsewhere that we are very probably all a bit barmy. That said, should we not accept the truth in the subtext to much of this thread, which is that the automobile simply is very expensive? Trying to make it cheap and succeeding is what has caused all the trouble. Perhaps if it's better, and more expensive, that is no bad thing? Elitist I know but that too is built into the automobile.
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>>>"The noise factor probably helps, but in terms of smog they really only displace it: all their energy ultimately comes from burning oil, and the overall gain may only be the marginal benefit of increased engine efficiency.
Even the degree of displacement depends on the balance of usage -- a hybrid used solely in the city will still produce all its smog there."<<<
Surely not ALL their energy comes from burning oil: some of it comes from regenerative braking.
Admittedly a hybrid used *solely* in the city will emit in that locale all the smog it produces, but a hybrid running some distance on an open road before having to stop-start through the whole centre of a city (which let's assume *doesn't* have Park And Ride) will emit a lot less smog in the city.
Indeed, with greater battery capacity (physically, or through better technology), it may be possible for that car to run purely on electricity whilst in the 'city' phase of its journey.
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Some folks stateside are tweaking their hybrids to give extra battery capacity and recharging them from the mains to minimise fuel consumption.
Accepted that the mains electricity generated does cause pollution but it's more efficiently generated.
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This looks like a version of the Honda Insight "electrically assisted engine" type hybrid, rather than the Toyota Prius "electric car with on-board power station" type.
I would think Hybrid technology, particularly the Prius type, is anything but a dead end, especially when used with a diesel engine. The city taxi market would look like a good one to crack. The cars might have batteries, electric motor/ regenerator and engine-driven generator but they do not need a gearbox and if suitable individual hub motors are developed, the diff and driveshafts can be binned too. Also hybrids should be able to use smaller engines because they can work at optimum speed and output rather than needing to produce adequate power and torque over a wide rev range as in a normal manual car.
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