Vintage Chrysler Airflow
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Will Diesels Have A Future In Europe?

Part two of Chris Ellis' The Cars of 2015 and Beyond

By Chris Ellis

To Part One

In my view, we may have reached 'Peak Diesel' already. In fact, natural gas now appears to be the rising star. Want proof?

Consider that sales of diesel cars in France and Germany have started to decline. Europe is becoming much more dependent on natural gas, as oil gets increasingly expensive to extract and world demand continues to grow. Natural gas is being delivered as CNG via pipelines from the lands to the east, and as LNG in tankers from Libya, Dubai, etc. All the major European manufacturers already offer CNG versions of one or more models. Honda is in league with Gaz de France to push its domestic gas refueling system, PHILL. Given the high levels of tax on diesel fuels across Europe, it's little wonder that bus and taxi companies are converting to CNG at a rapid pace, and sales of new diesel taxis and buses are falling away.

The European Commission and most European governments have just started a major push towards biofuels, and we can anticipate aggressive promotion of E85 (or similar) across Europe in order to achieve the demanding targets already set. The success of E85 in Sweden has not gone unnoticed in Brussels, Berlin, Paris and Madrid, even if London has only just woken up to its attractions. (See: www.carpages.co.uk/saab/saab-biopower-part-1-01-09-05.asp?switched=on&echo=920660435)

The UK government is beginning to realize the full consequences of the UK's rapid transition from being an oil exporter to becoming as dependent on imports as the US. All those lovely oil revenues gone, gone! Meanwhile, England's wheat farmers, the most efficient in Europe, are pawing the ground, waiting for the government to declare its hand on the level of tax on E85. If the UK government gets it right, diesel will then wither away, in one of the few European countries which is already conforming with the European Union's decision to achieve tax parity between diesel and petrol. Soon, the only reason for buying diesel will be if it costs less per mile than E85. It won't in the UK, and probably not in France, Italy and Spain either.

At last, the Germans (and others) have woken up to the environmental and health problems caused by two generations of 'dirty diesels'. Radical plans to enforce scrapping of older diesel cars are on the table, which are beginning to soften the firm residuals that diesels used to enjoy. As Germany effectively has no government until at least January 2006, and the Greens could swing it either way, the jury's out in Germany. So sales of new diesel-fueled cars could begin to melt away, as the new ultra-frugal, gasoline-direct-injection, small and medium sized cars reach the showrooms, particularly if the Greens insist the new government moves towards fuel tax parity. Then Europe may not have any spare gasoline left to sell the US when the next big hurricane storms in.....

Incidentally, the total population of geographic Europe, which includes Russia west of the Urals, is already over 700 million, well in excess of China's stated objective of 500 million by 2100. That's roughly 50% larger than the total North American market. We've stopped trying to kill each other off. Not a lot of marketeers realize that the potential 'single market' is even bigger. Given that negotiations have already started for Turkey (long a member of NATO) to join the EU around 2015, and that an application from Russia would certainly be welcomed by it's old ally England, the EU may well extend across much of Asia by 2020, and will obviously require a new name. How about 'United Nations (North East)'? Or 'the United Kingdoms of Spain, Norway, Denmark, Sweden, Belgium, the Netherlands, France, Italy, Russia, Bavaria, Prussia., etc, etc......'

And then?
It is important (to engineers at least) to make a clear distinction between diesel FUEL (i.e. a fuel derived from the heavier end of petroleum distillation) and compression ignition ENGINES, often referred to as diesels, after their inventor. The heavy distillate of petroleum caught the name from the engines! Put simply, diesel fuel is really 'bad' (our 'not-friends' have most of it, it's carcinogenic, it contributes to Global Warming and the tank is probably half empty already), but compression ignition isn't.

That's why I'm relaxed about Hawaii falling in love with 'diesel' engines, because they are going to compress vegetable oils with them. Provided Hawaii can stay on top of the emission problems, this is a good local defense against the 'three horsemen', Global Warming, Peak Oil and Energy (in)Security. We don't know who or where the fourth horseman is yet, but she sure as heck must be out there, somewhere, waiting to ride in!  
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However, the vehicle manufacturers would prefer a single 'World Fuel', identical in specification wherever their engines are sold around the world, but derived from a range of feed stocks, each appropriate to its region. (Of course, the oil companies may insist on 'almost identical', because some fuel additives apparently have quite incredible marketing properties, vying with Viagra in their potency.) The concept is that 'World Fuel' (VW have already registered the name Sunfuel) could be made from petroleum in Norway, sugar cane in Brazil, natural gas in Dubai, switchgrass on the Great Plains, in South Africa and in the Ukraine, and wheat in Somerset. And guess what? The 'World Fuel' specification bears a striking resemblance to E85. Naturally, engine designers know the characteristics of their ideal liquid fuel, and these are dominated by considerations of overall efficiency, not just combustion efficiency. They are asking Big Oil for a World Fuel, and are hoping most of us will want to use it. My apologies to them in advance for what I'm now about to write on engine efficiency, because it's an attempt to simplify a very complex subject. But here goes.

'Engines 101' tells us that, according to that great ingenieur Sadie Carnot, compression ignition (CI) must be more efficient than spark ignition (SI). Rudolf Diesel was born and grew up in Paris, so he was able to read Carnot's papers, in the original French. (See: www.vor.ru/English/whims/whims_036.html). As they say, the rest is history. In practice, the superior efficiency of compression ignition was, and will remain, true for large, slow engines, in ships, trains, etc. But once you factor in size and weight, the balance begins to shift, at the system or vehicle level. For the technical, if you have a 'level playing field' where two similar sized compression and spark ignition engines have direct injection (i.e. no throttles), similar variable boost turbochargers, etc, then, if the engines both have the same compression ratio, the spark ignition engine will be marginally more efficient. But diesel fuel can accept a much higher compression ratio than gasoline, so from now on the principal basis for a diesel engine's claim to higher efficiency will come from its continuing ability to take more turbo boost than a gasoline engine. But this means the diesel engine must be more rugged and therefore heavier and more expensive. But then you knew that already.

For example, the French establishment has decided that it would like diesel-fueled cars to be capable of winning the famous 24 hour race at Le Mans (more sponsors, ma cherie!). To make that possible, gasoline engines are limited by the rules to a capacity of only 4 liters if turbo- or superchargers are used, while diesel-fueled engines can be 5.5 liters, a capacity advantage of no less than 37.5%! (For the rules in detail, see www.mulsannescorner.com/2004LMP12.pdf)

But Le Mans is an endurance race, and diesels are more efficient, so why do diesels need an 'unfair' advantage? Basically, because they don't rev. And revs mean Power. At Le Mans, the engines are at, or close to, full power most of the time. To achieve power parity, you need a bigger diesel engine, a heavier, more expensive engine. And, surprise, surprise, the Sunday Times journalists found the same 'unfair contest', but in miniature, when they lifted the hoods of the two Citroens.

The little PSA diesel is almost as good as it currently gets in terms of diesel technology. However, it needs one more cylinder, 40% more capacity and a turbocharger to (almost) match the power of the 3 cylinder, 1.0 liter, naturally aspirated Toyota (made in Poland) gasoline engine in the other C1. The extra cylinder is the key to understanding why, in practice, a small gasoline engine can match the fuel consumption of a small diesel. It's about internal losses, friction, windage, bigger oil and water pumps, etc, etc. Any gains that compression ignition may make through more efficient combustion can be lost by the time the net energy reaches the transmission. It's not just about the combustion process!

Citroen ask us to pay roughly 15% more (at least $1,500, even after discounts, etc) for the identically equipped diesel-engined car, which delivers marginally inferior performance, and is simply not as 'nice' to drive. I've driven the similar gasoline-only Peugeot 207 (with the same Toyota engine as the C1) on an extended test, and it's a great little machine, even better than my daughter's Toyota Yaris. The engine is a peach, and sounds like a small straight six, once off idle. Think micro BMW, much sweeter than the crude engine in the current MINI Cooper. The Toyota engine is state-of-the-art for small engines, in that it has twin overhead camshafts, variable valve timing and sequential fuel injection. But it has none of Ricardo's LBDI goodies, not even direct injection, which is now spreading rapidly through the medium sector. I suspect Ricardo (or even Toyota themselves) would have no problem in squeezing another 15% mpg out of it at most speeds, if cost wasn't a major constraint.

So the cynical answer to why the diesel version is offered at all in the UK might be as follows. Paying extra for the diesel version still makes real financial sense to customers in those countries which tax diesel fuel less savagely than gasoline, IF the gap in residual values between the diesel and gasoline versions remains roughly the same as the original premium. In the UK, for a brief period, small diesels were genuinely and significantly more economical than gasoline cars (because, then, they weren't able to compete on performance, so didn't try). Consequently, a 'frugal' brand image has been built up, which has plenty of momentum left in it. Also, diesel engines make more sense in (conventional, but not hybrid) large cars, so that helped sustain the image aspirationally.

PSA's marketing department may well find it instructive to compare the sales results for the 'take it or leave it, gasoline-only' offering from Peugeot with the choice offered by Citroen. Of course, the furor created by the Sunday Times article may now ruin the 'experiment', if that's what's going on. In the UK, the logic justifying the purchase of a small diesel car is beginning to unravel. Once the residuals collapse, it's over. We are about to observe a classic example of market momentum. You can fool some of the people for a surprisingly long time!

The 'fig leaf' provided diesel by lower taxes in many European countries will gradually be whittled away by governments who already realize the full costs of allowing what was a perfectly sensible idea fifty years ago to survive well past its 'dump date'. Until now, they've believed it's just not possible to raise diesel taxes quickly, because that would risk having to admit a mistake had been made. And probably provoke fuel riots.

Now let's move beyond the somewhat suspect result of the Sunday Times test, and focus on Citroen's own UK government test figures for the two types of C1, bearing in mind that the use of Imperial (rather than US) gallons inflates mpg numbers by roughly 20%. The gasoline version gets 51.4 mpg urban, 68.9 extra-urban and 61.4 combined. The diesel version gets 53.3 mpg urban, 83.1 extra-urban and 68.9 combined. The key point is how close the urban figures are, with diesel offering only a 1.9 mpg advantage, less than four (not forty!) percent. If there is apparently near-parity at a steady 50 and (probably) at 70, then why would you chose a small diesel over a small gasoline engine for your Prius-sized hybrid, if hybridization completely hides the 4% deficiency of the gasoline engine in the city? Because you live in Paris? Is that all? How long before there is fuel tax parity in France? Before your car is more than a few years old, at most. Riots or no riots. Have you ever seen the French riot police in action? Truly Formidable!

The European urban cycle is roughly equivalent to the federal city cycle, and the extra-urban cycle is similar to the highway cycle, and just about as useless as an additional indicator of 'real world' fuel economy. The extra-urban cycle is not much more than a faster version of the urban cycle, still with an average speed of under 50 mph, and therefore reveals almost nothing about relative fuel consumption between different shaped vehicles at cruising speed. The majority of drivers in both the US and the UK experience a variable personal mix of city/urban driving combined with cruising close to the freeway/motorway speed limit. So the additional numbers we would like to have are for a steady 70 mph. The Sunday Times result leads us to expect parity, at least, from the two C1s, if not a clear win for the gasoline version. The 69 bhp Toyota engine is not even beginning to break sweat at 70; the diesel certainly is, with only 55 bhp.

Publication of the '70 mph mpg league table' would enable each prospective owner to form his or her own view of the probable real combined mpg of the cars on their shortlist, for each individual's own particular city/cruise mix. Come on EPA, we all need to know! Of course, the manufacturers already have the steady speed mpg numbers, so it might not need any extra testing, given the ease with which cheating can be exposed. Who's going to be the first to advertise how good they look at 70? My guess is Mercedes, because they DO look good, even for the big machines, even on gasoline. The Mercedes S-Class takes the effort to lower itself less than an inch at speed, to make it safer, but also to reduce fuel consumption. Mercedes obviously believes that height matters, and that an inch can make a real difference. On this particularly sensitive topic, Mercedes are right, as any tall lady aerodynamicist will confirm.

I don't imagine for one moment that Ricardo are planning to given up on small diesels just yet; they probably have several interesting cards to play. It also looks as if LBDI is not the last word in petrol engines for non-hybrid cars, judging by the following recent press release. www.ricardo.com/media/pressreleases/pressrelease.aspx?page=12

Equally interesting is Saab's BioPower engine. While the application of flexible fuels has been pretty casual in most US designs, Saab have done a professional job on their latest engine, now that Sweden is committed to biofuels. As any petrol-head knows, high compression is good in a gasoline engine, and a key limitation is the octane rating of the fuel, typically 95 or so globally. But E85 is 104 octane, which potentially means more power and better efficiency, and a reduction in the compression ratio advantage enjoyed by diesel. As a general statement, US E85 engines are naturally aspirated and must run with gasoline compression ratios. That means they take no advantage of the superior efficiency that E85 affords. Bearing in mind that GM owns Saab, let's imagine what a US Saab might be able to do by next year, using technology that is already shipping all over Sweden.

Let's assume 'our' Saab's owner is based near a gas station with an E85 pump. So most of the time the Saab is refueled with E85, and can deliver up to 180 bhp from its 2.0 liter engine. And its fuel cost per mile is much better than on gasoline, because E85 burns more efficiently and is priced to compete on a cents per mile basis with two dollar a gallon gasoline (of blessed memory). But now our heroine has to go into darkest Gotham, where the wicked Oil Barons live who won't let E85 be sold anywhere within 100 miles. (Bruce Wayne has his own E100 flown in from Scotland for the Rolls-Royce gas turbine in the Batmobile, just in case you were wondering.) And she will need to refuel with dirty old GASOLINE! (Later, when she becomes Bruce's true love, no problem.)

But the Saab is smart. However much gasoline our heroine mixes in with however much E85 is still swilling around in the gas tank, the car senses the new mix and signals the variable boost turbo charger to back off appropriately. Now the E42.3 (say) is fed in, with air boost at a pressure low enough to avoid pre-ignition, and the Saab shoots off into the night. If 'shoot's the right word, because the 180 peak power has now dropped back to a mere 162 bhp. Not exactly dangerously slow, but still a little sluggish. Mind you, it's still more than the 150 bhp of the standard issue gasoline Saabs favored by Gotham's yuppies.

What if the BioPower engine replaced the 4-cylinder diesel in the new Swedish-built, Europe-only Cadillac BLS? You don't imagine GM haven't already thought of that? For an encore, add an AWD surge power unit with at least 200 bhp, and you could give the Batmobile a bit of competition, at least until that big turbine spooled up properly. Could GM sell some in the States? Is Bob Lutz a pilot? Bruce would buy one for Robin, for a start.

Is there anywhere left for diesel cars to hide?
Not in Japan. They shower before they get into the bath. Diesel - No Way! "It's not just the emissions, it's filling the smelly thing. And look what diesel fuel's done to my Ferragamos! Just because Honda makes the best small diesel engine on the planet doesn't mean the Japanese have to buy any!" (Japanese sales manager, Amsterdam)

Not in the US, for sure, because E85 will cost less per mile in a hybrid, even cruising at 70 (see proof below). E85 is also environmentally and strategically superior, and already has an 'installed base' of almost 4 million conventional E85 vehicles, with Bill Ford committed to pushing that figure way up, which will force the other manufacturers, including Toyota and Honda, to follow suit. As it's very easy, they will, very quickly. Then watch E85 pumps mushroom, on both coasts, from under the fertilizer of the Senate's tax credits. The Senate's demand for a doubling of ethanol production by 2012 is then as nothing to the potential market demand by 2010.

Just as work on the Energy Bill was coming to a close, Senator Barack Obama proposed (and House Speaker Dennis Hastert swiftly inserted) a clause in the new Energy Policy Act to provide federal tax credit to build E85 ethanol fueling stations across the US. This may prove to be the most important clause in the Act, when viewed from 2015 and beyond. (http://obama.senate.gov/news/050728-tax_credit_for_e85_fuel_in_energy_bill/). Watch out for headlines like "Long Lines at E85 Pumps" and "Switchgrass Rustling in Wyoming." You may think I'm joking. Not about the first one. Not sure about the second. How about "Fuel Cell Powered Harvesters Used Infra Red to Work Silently Through the Night" (IEEE headline?) or "Massive Crop Circles in Texas" (UFO News?)

Not for long in the UK. Consider the brand new VW Golf GT, with its Twincharger engine. (Notice the i has been quietly dropped from GTi. If everyone has it, there's no longer any point in flaunting it.) As 'Twincharger' implies, this has both a turbocharger and a supercharger, an approach already used successfully on some large Volvo trucks. As a generalization, much of what is going on in developing ultra-frugal gasoline engines is the application of techniques which have already been successful on large diesels, where fuel economy has always been paramount and has received the appropriate engineering attention.

The Golf GT has a direct injection gasoline engine of only 1.39 liters, yet it peaks at 168 bhp, 20 bhp more than its big-engined sister, the naturally aspirated direct injection 2.0 liter FSI. On the UK's combined cycle, it gets 39.2 mpg against the 37.2 mpg of the FSI. The GT is also 6 mph faster, with a top speed of 136 mph, and gets to 62 mph in 7.9 secs, down from 8.8 in the FSI. Now try telling me downsizing engines can't deliver both improved performance and better fuel economy! The fastest diesel Golf, the equally new 170ps version of the turbocharged 2.0 TDI, only manages 0 - 62 mph in 8.2 secs so it's not a true apples-to-apples comparison. However, the slower diesel manages to get 47.9 mpg on the combined cycle. But as we all know, the gap between diesel and gasoline mpg figures narrows mysteriously in real-world driving, courtesy of the misleading parameters of the official tests.

Here's the reaction of Greg Kable, writing in the magazine Autocar. "If this is the future for the petrol engine, the trend towards diesel powerplants could already have hit its peak. The Twincharger really is that good." So it looks as if we may have hit Peak Diesel before Peak Oil! Will a 'cellulosic hybrid' Golf GT, using a hybrid system similar to Honda's, sell well in Germany? Is the Pope German?

Now let's get creative. Imagine the big, 2.5 ton (even with only the driver) VW Phaeton sedan (www.vw.com/phaeton/offers_price.html), with only a 1.39 liter Twincharger engine in it. Now we 'hybridize' it, which saves the cost (and fuel consumption) of the supercharger, because the surge power unit does 'surge' so much better. (The Russians will love it!) It will also save paying the gas guzzler tax, $3,000 on the W12-engined version. As seen by VW, the hybrid comes with a built-in $3,500 discount, before the cost of the surge power unit and the net-negative cost of the power unit swap is taken into account. There is no fundamental reason why the hybrid vehicle shouldn't have a sticker price lower than the V-8 version, contrary to the journalistic myth that 'two motors must cost more than one'.

The Twincharger engine has been designed to run almost continuously at full throttle, to take the sort of treatment some German drivers sometimes get the opportunity to dish out on an autobahn. Consequently, as a more conventional 'turbo-only' unit, it would be quite capable of keeping the big Phaeton at a sustained 110 mph indefinitely, a speed most US Phaeton drivers wouldn't care to exceed, for fear of upsetting the local sheriff. If there is a powerful (say 200+ bhp), ultra-robust Surge Power Unit (SPU) to support the little (but still 168 bhp) engine, this particular version of the Phaeton would accelerate faster than the V-8 version at all reasonable speeds, yet use half as much fuel in the city. Do you really want that W12? I'm sure VW would be very happy to make the hybrid just as luxurious, just as expensive! Fancy a hybrid Bentley, Mr Beckham?

Even better than the Phaeton, take the sleeker, relatively light, AWD Audi A8, throw out the big lump, mount an 'almost flat' flexible fuel version of the 'Monocharger' engine under the trunk floor in what was the large spare wheel well, fit run-flat Michelin tires, and put the 250bhp SPU where the old lump was. You then get a second trunk under the hood, just like the Porsche Boxster, one large enough to take two more golf bags. The final flourish is to fit an aerodynamic undertray, reduce the radiator size and lower the hood line. This is totally practical because the 100 kg engine, with its hot exhaust pipes, catalysts, etc, has migrated to the rear. (Did I hear "Big Beetle"?) As a result of this shuffling of components, the already good drag coefficient of 0.27 drops to an excellent 0.22 and the freeway mpg figure falls a further 5 mpg. The top speed might be 'only' 150 mph, but the hybrid A8, in this configuration and with this SPU (already under development), should be able to out-accelerate any other version of the current A8. That'll give Mercedes something to think about! Of course, marketing may well insist on an almost flat I-6 of around two liters, so that buyers don't feel they've been short-changed, and allow honest German citizens to continue to hit the unofficial German speed limit of 155 mph whenever they feel like it.

Or will that SPU come out first in a hybrid Porsche Carrera 4? The engine's already in the right place. At last, a 911 with 'perfect' weight distribution. Vindication for Porsche (and old Beetle) fans. Some day, all cars will be (a bit) like this! Pure speculation, of course. Who said "bring back the Corvair"? GM was right, but just a little premature.

Times Article Viewed: 18223
Published: 09-Oct-2005


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