There's something strange going on in the public discussion about fuel economy - especially in statements and documents from major institutions and government agencies. A great deal of care is taken to be specific and inclusively detailed in describing different approaches to fuel economy. You get mellifluous statements like "The public is rioting in the streets demanding more fuel-efficient vehicles, alternative-technology vehicles such as hybrid electric vehicles, hybrid plug-ins, electric vehicles, and flex-fuel vehicles as well as higher fuel-economy conventional internal combustion engines and so there's no way we'll make it to the Cineplex in time." I'm paraphrasing, of course.
But that's not the strange part of the discussion. What's strange in the recent discourse, the all-but-moot Corporate Avergae Fuel Economy (CAFE) debate, the automaker double-talk about this vehicle exceeding expectations or that truck able to pull a large house while using only the gas required to pull a small house, is the utter lack of any mention of diesel.
I've done the research, I've read more press materiel than is healthy, and pretty much across the board, official documents and policy statements about fuel-economy technology just kind of ignore diesel engines.
I'm not saying no one's talking about the fuel-economy impact of diesel. Your bloggers, your industry journalists, your automotive analysts - you know, the elite - they're all talking about it. And European carmakers, they've got plenty to say about the possibilities - and actualities - of diesel. Even some US carmakers are starting to join in (albeit cautiously - more on that later) insofar as they are planning on offering a diesel version of one of their own models or t'other. But any official statement about bona fide, lets-put-that-in-stone policy just goes blithely along as though there's no such thing as diesel. Why? Let's explore.Is it because diesel is not as fuel-efficient as the other technologies?
No, that's not it. Estimates vary of just how much more fuel-efficient diesel engines are than internal combustion engines, depending on where you're getting your data from and what segment of the market is being analyzed, but Fueleconomy.gov
, which is administered by the US government, puts the mpg advantage of diesel engines at about 30 - 35 percent. (I guess that means we can rule out the explanation that no one in the US government knew about diesels.) Hybrids and electrics are beginning to close the gap, but on average still lag fairly far behind.Is it because diesels are dirty and smelly and noisy?
No, that's not it. Well, if the diesel vehicle in question was built thirty years ago, then yes, that's a distinct possibility. But today's diesel engine is actually 10 to 15 percent cleaner, in terms of CO2 emissions per mile driven, than the average internal combustion engine. Their emission of particulate matter has been reduced by more than 90 percent since the dirty, stinky version introduced by General Motors in the 1970s. And some diesels - Volkswagen's in particular - are among the quietest of any cars on the market.Is it because diesel engines are under-powered?
No, although it is pretty funny that Edmunds.com calls diesels' acceleration "drama-free." Diesels actually get much more power than an ICE does out of each unit of fuel burned, and they have a big advantage in low-rpm torque - making them great for grunt work like towing and hauling. (That is one of the reasons why so many trucks and tractors are diesels.) But most diesel passenger vehicles also have a turbocharger, which increases their high-rpm power as well. (Any vehicle, actually, can use a turbocharger; it's just that they're particularly effective in diesel engines. A turbocharger is basically an air pump, and diesels use up to twice as much air as an ICE, so can take better advantage of the turbocharger's boost.)Is it because diesel vehicles cost more?
There is a premium attached to diesel vehicles, in general, from $1,200 to $3,000 if you look at vehicle lines that have a diesel version and ICE version of the same model. That's because they cost more to make (and they tend to last much longer). Still, the extra cost is significantly less than the premium attached to hybrids and electrics - which everyone is talking about - so cost can't be it.Is it because diesel fuel costs more?
That is a more difficult question than it would seem. Technically, diesel is less refined than gasoline, so it should cost less, if anything. The question is complicated by the fact that diesel fuel and home heating oil are basically the same thing, so there's an increased demand during the winter months. Also, a great deal depends on the relative taxation of diesel and gasoline. In the US, diesel is taxed much more heavily than gasoline, and that's because it is politically feasible to tax diesel at that rate. In the current political climate, to say it's considered politically infeasible to raise gasoline taxes in the US is like saying it's politically infeasible to sell the Statue of Liberty back to the French.Is it because no one likes them?
Well, let's see. At nearly 5 percent, diesel cars have more than twice the share of the market than hybrids and electrics, which currently boast just 2 percent. Moreover, a diesel car's residual value is more than 30 percent higher than ICEs', on average. And diesels' "take rate" is growing - meaning the rate at which buyers choose the diesel version of a model when it comes in both diesel and ICE. It's grown from 12 percent two years ago to about 32 percent in 2011.Is it because The Big Three aren't big diesel players?
Ohhhh... now you may have something there. Now that I think of it, Ford, GM and Chevrolet put some demands on the table before agreeing to support the new fuel economy standards to be finalized later this year. One of them was that there would be several kinds of fuel-economy technologies that could earn automakers "credits" toward meeting their CAFE targets. These included aerodynamics technologies, improvements in heating and cooling systems, systems that capture energy when brakes are applied, and others. But there was one that was specifically to be off
the list. Guess which one it was? That's right - the ultra-clean diesel technology created by European automakers. No credit for diesel, or they walked.
Of course, this may change now that US automakers are starting to talk about bringing out diesel versions. Ford has already introduced a diesel version of the Focus - only in Europe to date, but there is talk that they may bring it here if interest continues to percolate. And General Motors, whose 1970s Stinkmobile was responsible for the bad taste left in consumers' mouths - sometimes literally - for diesel, is definitely working on a diesel version of the Chevy Cruze. Maybe if all the automakers are involved, there might be a chance for a fuel economy policy in the US that was at least somewhat technology-neutral. I would definitely riot in the streets for that.