The Diesel Illusion in North America

[Actuary]

Diesel is actually cheaper, they just tax the crap out of it.

 

We buy diesel at $4.00 a gallon for the boats, the same stuff sold at the gas station is $4.80.

I don't know where you're buying your boat diesel, but if you pull up to a pump in the U.S., the average per gallon tax on diesel is within a few cents of the tax on gasoline.

[chenc544]

Isn't the simple solution to build refineries that can make more diesel? As the article states the US hasn't build a new refinery in almost 30 years, isn't it about time we start doing that?

[sactojesse]

The only disadvantage that's left for diesel engines then is that they produce a higher amount of nitrous oxides due to the lean burning.

That's been the major stumbling block for getting light duty diesels certified for 50-state use in the U.S., particularly in light of the more stringent 2009 model year emission standards. The current Clean Air Act regulatory scheme in the U.S. focuses on criteria pollutants such as ozone (formed by a reaction between NOx, reactive organic gases [ROG], and sunlight), carbon monoxide, and particulate matter. In contrast, much of the EU focuses on greenhouse gas emissions, which are primarily a function of fuel economy.

[Actuary]

Three reasons why we don't all need to drive diesels:

 

1. Diesels are more efficient, but not by as much as most people think. The energy density of diesel fuel is approximately 15% greater than that of gasoline.

 

Yes, supply and demand affect prices, but demand is affected by "how much can I get for my money." And, with diesel, the answer is, 15% more energy per gallon than gasoline. That means that, if there were not substantial infrastructure supply side costs of switching production between the two, diesel should cost approximately 15% more than gasoline. So if gasoline is $4.00, diesel should be $4.60. That's about where we are today. So the relative prices are in an equilibrium of sorts.

 

As far as fuel efficiency goes, the most modern direct injection gasoline engines are able to achieve MPG numbers which are only 20-25% lower than that of diesel.

 

Factoring in the higher energy density of a gallon of diesel, these engines are only 5-10% less efficient per unit of fuel energy (measured in Joules, not gallons) than diesels. The reason for this is that the combustion chemical reaction of diesel is better at pushing the pistons, and creates less wasted heat energy. This difference will likely never be overcome, but 5-10% is not a particularly large number at this point in time.

 

 

2. Diesels spew more particulates into the air. Even if the newest urea based filters are able to capture 95% of these (measured in mass), that leaves a whole lot of tiny particles that may very well be hazardous to our health. In other words, for every basketball the filter captures, several hundred ping pong balls are not captured, and these may very well pose a real health threat.

 

 

3. Widespread use of diesel by commuters will have unintented consequences. Let's let the truckers use the diesel, since they need it most with large loads and constant highway speeds. If commuters start using diesel, then that will raise the price of diesel for truckers and commuters alike. This will eventually find its way into the price of food and other commodities, as the cost of shipping goes up.

 

We don't need to waste money building more refineries to make a greater percentage of diesel. We need to develop battery technology so that commuters can purchase all electric vehicles (not hybrids). ICUs are incredibly complex, inefficient, and costly. Electric vehicles seem exotic, but would actually be much simpler to engineer and build. And once we perfect the technique of burning coal with ultra-low emmissions, our overall emissions well/mine-to-tailpipe will be much much lower. And we won't need to send so much money overseas, since we have more coal than anyone else.

[PhilT]

I don't know where you're buying your boat diesel, but if you pull up to a pump in the U.S., the average per gallon tax on diesel is within a few cents of the tax on gasoline.

 

We buy it from all the major suppliers, Esso, Shell, Petro Canada etc etc, normally 25,000 gallons at each fill up.

 

But then, the boats do use 3,500 gallons a day

[BernardP]

Very interesting comments, Actuary.

 

Very much in line with the thread title: "Diesel Illusion"

[SLegacy99]

I read a thing about adblue today in the new BMWs. Im not sure that its worth it. After your 4 year maintence plan is up, you have to pay for the urea refills. And what happens when you run dry. Who is mandating that you pay for the refill, and if you don't it doesn't seem to me that this car would pass as 50 state legal, but who know. Diesel particulates are quite hazardous to everyone's health.

 

Also, the 328i is only 1/10 of a second slower to 60 MPH than the 335d.

 

328i: 19/28 MPG

335d: 23/33 (but costs more and uses more expensive fuel)

 

Direct inject the 328 and I think you'll have the power to match the speed (though not the tourqiness obviously) of the 335d. And the margin of fuel economy will be diminished as well.

 

BMW diesel not all its cracked up to be is my point.

[ShrinerMonkey]

I believe the urea injection cars allow you a certain number of starts after the urea tank runs dry and then will no longer start. Of course you will only be able to get the urea at the dealer at a billion dollars a quart as is usually the case with German auto dealers.

[SLegacy99]

Thats why I'm not thinking that adblue is all that great. I hope that safeguard is in place though. I am interested to see the pollution scores in relation to the 328i.