Patrick:

Your reasonable doubts are already proved to be wrong. In my Vancouver no less than 300 Priuses proved to be incredibly economical in taxi service. Fuel savings are about 15$ per day, plus substantial savings in brake service and overall maintenance. Prius taxis are running 24/7 for up to one million km, and even Toyota officials were stunned by longetivity of their batteries.

It's off topic, but series hybrid results in losses not present in a mechanical drivetrain during highway conditions. The Prius arrangement is designed to be (almost) a gear-to-gear transmission during highway driving.

Anyhow, what's with all the speculation about something other than the topic at hand? Methanol is currently made from natural gas and can't be efficiently produced from biomass, and is not a solution going forward. The pie in the sky hybrid powertrain designs are interesting and might have application at some time in the future but we need to reduce consumption in conventional powertrains NOW, and right NOW it would be so expensive to produce some of the pie-in-the-sky powertrains being discussed that nobody could afford to buy them. Right NOW, improved efficiency in gasoline powertrains and improved consumer acceptance of diesel powertrains is a GOOD thing, is it not?

Brian, there is the conversion losses in a series hybrid at highway speeds, of from 9-20%, but these are offset by having a more efficient engine running more efficiently, even at highway speeds, where the big engine needed to accelerate an ICE vehicle, is not running at optimal efficiency at typical 50-60 mpg highway speeds, especially if on a downhill grade.

With a series hybrid, if you use wheel motors, you can eliminate drivetrain losses which amount to 15-50% of engine shaft hp output in a typical ICE vehicle, and these losses are even worse in regen mode for a hybrid.

Actually methanol made from natural gas would be an advantage because we have more natural gas then oil, and large reserves in North America, rather than using Terrorist Funding Middle East Oil. For example large reserves in the Mackenzie Delta, a lot cheaper to convert it to methanol and ship the methanol in tankers, then to build an environmentally controversial $20 billion pipeline to transport some of it to southern markets. Methanol can be made economically from Biomass through the Fischer-Tropsch process, more economically than biocellulose ethanol.

BMW is achieving many improvements in F1 also.
Durin the 2007 season it seems that they are going to make more points than Renault !!

Two cylinder, two cycle opposed, air-cooled diesel doing nothing but driving a generator at optimised speed is the way to go.

We should have been doing it since 1979.

Lucas, I'm interested in that type of engine, do you have a link?

I think the more important question is why would anyone buy a diesel BMW?

PLENTY of people in Europe already buy diesel BMW's. The people criticizing BMW for this need to take their American-centric blinders off. In Europe, something like 70% of BMW 7-series cars sold have a diesel engine. It is the Americans who are behind the times in this regard.

I don't buy the constant-speed engine and series hybrid argument. If the engine power output matches the electrical power demand at the wheels during cruise, then perhaps it is possible for the powertrain losses to be kept low, but if they don't match (i.e. accelerating, going uphill and downhill), then the electricity has to be stored in a battery, and that introduces quite a bit more loss.

The diesel engine in my VW Jetta is around 20% off its peak efficiency "island" on the BSFC map at highway cruise (but has an efficient gear-to-gear transmission). Would chopping a cylinder off in order to get it on the peak-efficiency "island" compensate for the additional powertrain losses in an all-electric drive? I'm not so sure. A Prius-style powertrain (allowing gear-to-gear transmission at highway cruise) fed by a VW 3-cylinder 1.4 TDI (an engine that is already in production) might be optimal, but costs too much ... Its day will come; Peugeot/Citroen looks like they will be first to market with it ...

Personally, I think the armchair auto engineers should either get off their armchairs and do something more than a paper exercise, or shut up.

Europeans buy them..they must have a reason to do that..

Thanks Brian P...you said exactly what was in my mind. Had
been in Europe in February and rented a Renault Stationwagon with a 1.5! liter turbodiesel engine. Plenty
enough power and 4.5 -5 Liters/100km ( around 48mpg)..

Get a life

People buy diesel BMWs (for for that matter diesel anything) in Europe because they can't afford to drive gasoline powered cars. Gasoline is taxed to a higher price than diesel fuel in most of europe. The price of fuel is manipulated by a handful of misguided politicians. THIS IS THE ONLY REASON DIESEL CARS EXIST. Think about it: $7 a gallon. What would you drive?
This is an indictment against diesel cars. Every large European city is choking on diesel soot. Try going for 3 mile run in Barcelona and tell us how your lungs feel.
Secondly Europe's stupid taxes on all road fuels is forcing the price of gasoline in the US down. The high price of fuel over there reduces consumption which leaves more crude oil available on the world market. If Europe wanted to encourage the US to reduce its oil consumption it would drop fuel taxes on its own citizens. Consumption in Europe would spike while the price of gasoline here would also increase. But they are too busy being sniffing their own smug farts to open accept the free market truth.

The people in europe have voted for the parties who rise the fueltaxes. If I get you right, europeans have to start
driving gas-guzzlers to increase fuel demand on the world
market so prices in the states go up, so US citizens are
forced to buy more fuel saving vehicles. What is then achieved globally. This is really a amazing thought.. by
the way diesel-fuel in most european countries is meanwhile only slightly cheaper than gas.

In some markets BMW means diesel and where talking about more than 80% of sales. Some times you see a petrol BMW, mostly a 6 Series or an M version of the other series, almost everything else is a diesel, same thing for Mercs.

Even with the price of diesel approaching the price of gas, there is a great advantage of operating a diesel engine over a petrol one, especially if you have to drive lots of miles every year. Diesel it’s a strong sales argument, as I’ am writing these words I can see trough my window a big outdoor saying something like this: “Come see the new Alfa Romeo 159 2.4 JTDM, the only diesel with 200Hp and 6.8 litres per 100Km”

Well, that’s not true, BMW did it with only 2000cc.

About Europeans being choking with diesel soot, I have my doubts, at least in my region they don't. Perceived air quality is now better than it was 20 years ago even with the recent diesel boom. Diesel in Europe it's not new, there are plenty of diesel LDV's with more than 10 years, build with less stringent emission standards that must be quickly phased out. Not to mention HDVs and MDVs.

Although in Europe, emission standards for diesels are less stringent concerning NOx and PM (comparing to Tier II bin 5) they’re good enough and continuously raised in a way that keeps the balance between fuel efficiency, air quality, CO2 emissions and industry RD efforts. That’s not always easy and without pain, as it is being with the new EU directives concerning CO2.

The other reason that people buy diesels in Europe is because they are often much nicer to drive than a gasoline variant of the same power output. Massive torque right in the middle of the range makes the diesel faster than the gasoline variant in most in-gear overtaking conditions.

The fact remains that Europe subsidizes cheap gasoline in America by taxing its own citizens.

One thing that often gets overlooked is the fact that many people need vehicles that have the capacity to haul and tow loads over great distances that PEV or PHEV may never be capable of doing at the same efficency that diesels already provide. Diesel hybirds might be a great option that may become more and more common in the near future. One thing that diesel has over other alternative fuels is that the existing infastructure (auto makers and fuel distribution) can easily be shifted to diesel. Speaking of efficency, is it not interesting to note that diesel is consistently more expensive than petrol when considering the fact that diesel requires less refining! Makes no sense to me. Anyone know the real answer why and how to change it?

..BMW and Co "lobbied" the new EURO V and VI emission legislation that are well behind the strict US-standards imposed years ago. A Diesel produces more greenhousegases as a petrol engine and more harmful exhaustgases. But if the German/European carmakers had to drop ther dirty Diesels, they would have no chance against the Japanese. That the Eurpeans do with the Diesel? Protecting a market!

BMW and Co suck. Variable valves are standard even on the smallest engine Toyota offers on the European market. Look, VW sold a 2l 4 banger 8 valve engine in ther last Golf/Jetta/Rabbit Mk IV line on the European market. Stoneage made by Volkswagen.
All the brains of the excelent engeeniers they imploy are being missused to develop bloody Diesel engines instead of doing something more advanced. It´s a wast of capacities. And there accountens are looking around to find someone the can bribe. It´s someone else.

Everyone who likes the Diesel should come to Paris, London, Berlin etc. and take al full breath. Period.

The new Peugeot 308, due out in 2008, will also be on offer in a diesel hybrid version. Its electric engine will allow all-electric operation up to 30 mph, and might be dimensioned to about one quarter of the main ICE unit maximum power output (a 1.6L, I4, 109 hp unit). This follows closely the "307 hybride" concept, which was presented at the start of 2006, and is somewhere in between a mild hybrid and a full-hybrid in terms of ICE-electric ratio. No pricing yet, but a premium of 1500 Euro over a similar diesel-ony unit would be the target. Fuel consumption of 3.4 l/100km compares to 4.8L for a current 307 with a 1.6L, I4, 109 hp.

Wonder if there is any input from BMW on this one ? Or whether Ford Europe would participate ?

Diesels are smelly, noisy, polluting, inefficient in city traffic and worst of all they make you look like a tightwad. Nobody wants a diesel BMW. Europe is choking on its own diesel exhaust because they have taxed gasoline into the stratosphere in order to save the blue whale or whatever. Lucky for us as towel head correctly pointed out, their subsidy is our gain.

Folks, you will not "choke" on the exhaust of any diesel engine that meets either US EPA Tier 2 standards or on Euro 4 (or upcoming 5) standards. In many cases the regulated emissions coming out of the tailpipe of a vehicle that meets T2 B5 (doesn't matter diesel nor gasoline; the same requirements apply) will be cleaner than the air going into the engine.

YES, some European cities have a pollution problem, but *newer* cars are not responsible. Keep in mind that Euro 2 was in effect as late as 1996, with much higher allowed emissions, because the technology had not been developed yet.

Diesel engines are not regarded as the "cheapskate" choice elsewhere in the world. In Europe they are generally regarded as the environmentally responsible choice. Nobody here (Canada) criticizes me for driving a VW diesel. Even here, they are primarily regarded as the responsible choice.

As for a diesel being "inefficient in city traffic"? WRONG, a diesel engine uses around one-third to one-half as much fuel at idle as a comparable gasoline engine. Diesels do much better than non-hybrid gasoline cars in city driving. YES, an electric hybrid could trim that down, but it's not currently economically feasible. Engine stop-start systems can address this in a simpler manner.

My Jetta TDI in the real world has fuel consumption comparable to a Prius in the real world (forget EPA's dreaming) but kicks the Prius into the weeds in terms of driving dynamics, and the next version due in 2008 will have extremely low exhaust emissions.

I don't want to buy another four-wheeled vehicle with a gasoline engine.

No doubt, Brian...the cacaphony anti-diesel zealots are deafening with misinformation. Ive been in all of the mentioned euro cities and many more. Although I never lived on a street corner, I never noticed the "overwhelming diesel exhaust" either. Here in Chicago ULSD is finally everywhere and its rare to see the "old black plume" even from older trucks and buses.

After 80K trouble-free miles, my 40mpg diesel is finally down, waiting for an air mass meter...so Im back to the gas engines 25mpg for a short spell. 600mptank vs not even 400 is an easy decision.

I also will not purchase a new gas-powered car.

"As for a diesel being "inefficient in city traffic"? WRONG, a diesel engine uses around one-third to one-half as much fuel at idle as a comparable gasoline engine."

You don't say. Does your TDI get 48mpg US (not your weirdo canadian gallons in city traffic the way my Prius did on its last fill up? Does it shut off its engine while sitting at a light? Have you ever put a wet towel over your tail pipe to see what king of particulate matter it picks up? Brian your whole argument is hollow. Given a choice, nobody in their right mind would blow $40-50k on a 4cyl diesel BMW and you know it.

I believe that emission controls on diesel engines are more effective and economical with the typical 1/3rd size engine used for a series hybrid generator.

I'm going to buy the ultimate driving machine... with a tractor engine.

LOL

For the record, my TDI with me driving (which means 130 km/h plus on the motorway ...) uses 5.2 - 5.5 L/100 km. I don't care whether the engine stops at a red light (it doesn't), it all comes out in the end result (the fuel consumption number). I can get consumption down to 5.0 L/100 km with a less heavy foot, but I've got places to go and not much time to get there. My particular example doesn't have a particulate filter, you have to wait until the 2008 model for a totally clean and soot-free tailpipe.

Can your Prius run on renewable-source fuel without any modifications? Mine can ... and DOES, when 100% biodiesel is available (which it WAS, all last summer). Biodiesel has a much greater CO2 reduction factor than *anything* you can practically feed to a spark-ignition engine.

If the choice were available to us in North America, I WOULD buy a BMW with a diesel engine.