The great powertrain debate - diesel vs hybrid.

A certain fat British bloke TV personality is famous for rubbishing environmental credentials of hybrids, throwing his support behind the new generation of clean diesels which gets better mileage than the pious Prius. Twenty year olds who know no better watching Internet pirated copies of his TV series - believe this to be the gospel of universal truth. Honda and Toyota fanboys start flame wars on Internet forums, pointing out that diesels continue to burn fuel, which is a diminishing resource and is this not a very smart solution and it produces higher NOx and carcinogenic particulate matter. Diesel proponents counter back by saying that hybrids are no better than conventional cars when one considers the battery production and disposal issues.


Expect debates to heat up again with the introduction of Honda's second generation Insight and Toyota's third generation Prius. The third generation Prius will be introduced in Malaysia and Thailand for the first time later this year. The Insight however will have to wait. Honda's Suzuka plant (the only production sight for Insight) is already overstretched to churn out as many Insights as it can to meet strong demand in Japan (Insight is now Japan's best selling non-kei car) and Europe and even its U.S. launch has to be delayed.

Below is autoindustrie blog's thoughts on the issues under contention :

1. Hybrids are not so green when one takes into account the batteries.
Compared to what? How can one take into account the entire supply and production chain of a hybrid vehicle's energy source but selectively ignore the same for a conventional diesel or petrol powered car? Diesel proponents argue that hybrid cars are more harmful to the environment because of battery production and mining of precious metals but choose to ignore to environmental cost that are associated with oil exploration, drilling, refinement, storage and transportation. Batteries are made to be recyclable, with most of the precious metals inside them can be recovered. Fossil fuel and its byproducts however cannot be recycled.

The hidden human cost of oil extraction.

Old Texaco oil barrels left on the side of the Aguarico River, near Lago Agrio, Ecuador.

An unlined waste pit filled with crude oil left by Texaco drilling operations years earlier lies in a forest clearing near the town of Sacha, Ecuador.

Maria Bravo stands by an open waste pit and flares in an area where she lives in the Guanta oil field.

For more images, go to Crude Reflections and also watch the short documentary here.

2. Hummer H3 SUV has a lower life-cycle energy cost than a Toyota Prius hybrid.
This famously circulated report was produced by researcher Art Spinella, President of Oregon-based CNW Marketing. Spinella is formerly from J.D. Power. The report has since been widely discredited for lacking in peer-review, inconsistent assumption and selective use of data. Dr. Peter H. Gleick of Pacific Institute has published a paper, re-analysing CNW's paper here. The results of the re-analysis is as expected; both “lifetime energy” and “energy per mile” for the Prius are far lower than for the Hummer.

Extraordinary claims require extraordinary proof, Carl Sagan (late), astronomer.

3. Diesels are more economical and provide higher mileage than hybrids.
That is true. But one should also take into consideration that price of diesel has been consistently higher than petrol for a good part of this decade. This is of course referring to deregulated markets where no price controls are leveled on diesel or petrol as they are locally. The increasing margin between prices of diesel and petrol has diminished much of the higher fuel economy advantage provided by diesels.

In Europe, close to 55% of all new cars sold are diesels. 30% of all new cars sold in the burgeoning India are diesels. Diesel is also the primary fuel for all farming and industrial equipments. Diesel prices will also spike during winter season as heating equipments rely on diesels. However the world's diesel refining capacity have yet to keep up with this rapid growth of diesel consumption, leading to a shortage of supply. It is for this reason that diesel prices are on the uptrend and while prices have dropped significantly due to the current economic recession, do expect things to pick up again when the economy recovers and consumption increases in tandem. Refinery capacity cannot be added quickly in the short term and fuel stations need significant renovation to accommodate more / larger diesel underground storage tanks (which differs from petrol storage tanks).

To meet increasingly tough EU IV and V and US BIN emission regulation, car makers rely on ultra low sulphur diesels to keep their new generation clean diesel engines running. Of course this would also imply that more sophisticated refining methods will have to be adopted, further driving prices up.

Diesel engines also cost more to produce and thus diesel model variants carry a higher price tag against their petrol powered counterparts, further extending the period / distance required to recoup any savings. Diesel engines run on the principle of compression ignition (compared to spark ignition in petrol engines). Thus, diesel engine blocks need to be made stronger to withstand the higher pressures. The need to generate high power at low engine speeds also means that stroke length of diesel engines are longer. Crankshafts, connecting rods, etc etc. have to be "overbuilt" more than a conventional petrol engine. The increase in material cost is what makes diesel engines to cost more.

The needs to utilise exhaust gas treatment like Selective Catalytic Reduction (SCR) with Diesel Exhaust Fluid (DEF) to placate increasingly tough exhaust emission regulations will further increase cost of diesel vehicles.

In the short term, diesels might be more economical, but this might not be true for very long.

4. What about diesel-hybrids?



The idea improving an already very economical diesel engine with a hybrid setup is attractive. However we need to remember that diesel engines cost more to produce. Hybrid powertrains also carry a significant price premium over their conventional petrol powered counterparts. To combine two high cost components together makes such a proposition impractical to begin with. Moreover, diesel engines suffer from higher NVH. One of the key challenges in designing hybrid vehicles is to maintain a smooth transition between petrol engine power and battery power. The higher NVH characteristic of diesel engines makes this task a lot harder, requiring even further high cost engineering solutions. Of course, companies like PSA Peugeot-Citroen might disagree and proceed with development of their Prologue and Hypnos concept.

So are hybrids the solution then? Not quite so. The "holy-grail" of electric vehicles (referred from here onwards as EVs) and hybrid vehicles (referred from here onwards as HVs) are higher energy density batteries - at the moment this usually refers to variations of Lithium based batteries. Fancy batteries used in EVs and HVs of the future require many rare earth metals like lithium, magnesium, nickel and cobalt. At the moment the world's largest reserve of magnesium is in China. The world's largest reserve of lithium is in Bolivia. It is left to be seen if these regimes are any better than the Arabs who control OPEC.

I think by now you can picture in your head the sort of problem we will be running into very soon with EVs and HVs. The expected resource supply concern is further exaggerated by increasing demand for mobile electronic appliances - PDAs, MP3 players, notebooks, cellphones, etc etc. Even photo-voltic solar panels are joining the long list of industries competing for the world's rare earch metal resources.


50% of the world's lithium supply lies under the Salar de Uyuni salt lake in Bolivia. Both Toyota and Mitsubishi have approached the Bolivian government with a deal in securing lithium supplies, only to be sent away by Bolivian President Evo Morales.

"All they wanted to do was carry away the raw lithium carbonate. That's not what we're after."said Luis Alberto Echazu, the country's minister of mining and metallurgy in an interview with Time magazine

While the Western media might paint Morales as a Third world socialist dictator, I believe that Morales is acting in the interest of his people. NAFTA (North American Free Trade) agreement left Mexicans poorer and exploited by American seeking to escape tough environmental and labour laws back in US. Resource rich Africa was plundered by the West, leaving behind a series of irreversible political and social rift that continues to haunt the Dark Continent until today. Ancient South America too was plundered by the marauding Spanish. There is no reason to believe that the people of Bolivia will benefit from the menial and dangerous jobs at lithium mines, not to mention the environmental degradation to its salt flats if any mining activity is to be carried out.

Neither EVs nor HVs are the long term solution to our transportation woes. I may be a car nut but I also understand that demand for cars will continue to rise and that driving pleasure is inversely proportional to vehicle density on our roads. We can't have it both ways. The only way to move forward is to redesign society to adopt integrated public transportation. Private transportation and personal cars should be left aside, used occasionally for pleasurable drives. As Jay Leno once put it, it's just like the difference between the way people treated horses in previous centuries and today. Today, horses are used solely for recreation, no longer for dirty transportation use like they used to centuries ago. If petrolheads want to continue to enjoy their cars this is the only way to move forward.

At this point, some will want to argue about how real is global warming / climate change etc etc. I will not go into that. Sometimes I am amazed by the general stupidity of some people. There are people who can search and point to scientific research, and then proceed to use these as ammo along with their half baked knowledge in science, when the very obvious point is that even school kids know that vehicular emissions poison our air and it's bad for us. Whether is climate change real or not is beside the point. Earth has been around for 4 billion years and has gone through many periods of warming and cooling. No matter how polluted earth becomes, it will regenerate itself over time, long after we have gone. Earth does not need our rescue. We are the ones who need to be rescued from ourselves. So it is pointless to argue if global warming is man-made or not. We need to change our ways for our own survival, not earth's. I want my kid to see the same blue skies and breathe the same clean air I enjoyed when I was young.

The car industry have a collective responsibility to mend their ways. EVs, HVs, clean diesels, etc etc are not addressing the root of the problem - that our model of private motorized transportation is not sustainable. Companies like Toyota (Hino), Daimler (Mercedes-Benz commercial vehicles) and VW (Scania) have significant commercial trucks and buses operations and will be able adapt to such a change. But many others will falter and thus lobby hard against their government from such a move.