I would like to get a new car with better gas mileage, so I am considering a diesel engine. The cost savings due to less fuel usage compared to most gas cars is reduced by the higher price of diesel. The higher price of diesel seems to be a somewhat recent change though. According to data from the Energy Information Agency, before Hurricane Katrina the price of diesel was on average the same as the price of gas. Since Katrina the price of diesel is on average 8.7% higher than gas. Is there a reason for this? Or is it just oil companies trying to discourage people from buying more due efficient diesel cars since they realized consumers can not quickly react to higher gas prices?
Data is available at the Energy Information Agency website: http://www.eia.gov/petroleum/gasdiesel/
What kind of vehicle are you shopping for? The only vehicles available in the US that are diesel are mostly trucks with VW and Mercedes sedans; not sure if BMW offers a diesel or not.
Consider the price difference between engines, too. How much extra fuel could you purchase with the price difference? IIRC the Ford diesel engine is a 6 to 8 grand option over the base engine cost; not to mention you have to upgrade to atleast a 3/4 ton truck(F-250 or higher) to get the diesel option. A regular cab F-250 XL 2wd with the diesel starts out at $37k before you really get into the options for the truck.
The Mercedes diesel sedan starts at about $52k
VW’s website claims up to 42mpg(30/42) for a couple of their TDI models. Mazda, with the skyactiv gas technology claims 40mpg(28/40 with auto) with it’s 3 sedan. TDI Golf starts about $25k, Mazda skyactiv 3 sedan starts about $20k. How much fuel, at 2 less mpg, could that $5k buy?
Maybe Mazda will bring it’s skyactiv diesel tech to the states, but who knows how long that’ll take. I’ve heard rumors of 60 to 70mpg from that engine, but haven’t seen any specific claims
Any possible manipulation aside …
Diesel fuel prices have historically fluctuated with the seasons, rising into the winter and dropping into the spring. (Diesel fuel and heating oil are essentially the same thing.)
The switchover to ultra low sulfur diesel has run the cost up a bit, but it’s for the better. New vehicles need the cleaner fuel and it’s far more healthy for our lungs.
Our domestic US refineries use a different process than most refineries worldwide (catalytic vs hydrocracking), and produce less diesel fuel per barrel of oil.
I don’t own a diesel (yet), but I absolutely love to drive them … and it’s not just about the fuel efficiency … there’s just so. much. torque… 
It’s a supply and demand thing, and after the ULS mandate, (low sulfur) producing this fuel became more difficult…
Diesel is similar to jet fuel, and heating oil. Refineries establish production quotas and based on predictions refine various fuels. More heating oil prior to winter, more gasoline before the summer driving season. If they screw up the production vs actual demand it can take awhile to changeover refinery production to catch up with demand. Can all this be manipulated, YES. Oil companies, and refineries are driven by profit.
Recently demand for diesel and similar fuels has be higher than projections and therefore diesel fuel sells at premium prices. In Europe the differences between diesel fuel and gasoline is much less, both everything is very expensive in Europe. If the trucking industry has a big slow down, there might be excess diesel and the prices could go down to equivalent or even below gas prices. If you have a crystal ball perhaps you can figure out supply and demand.
It just seems USA refineries are more geared up to produce more gas and less diesel. Maybe this will change but my guesstometer says diesel is likely to stay more $$$ per gallon than 87 octane gas.
When I bought my diesel Olds in 1981, diesel was quite a bit cheaper. It has been rising ever since. Take a look at all the trucks on the road hauling imported Chinese goods around the country and that may have something to do with it. A lot goes on rail but there is still truck after truck after truck on the highways that was not the case 20 years ago.
Much of the demand push is from China and India, the two fastest growing markets for motor fuel…We import over 50% of our fuel. We don’t control the price…
@bscar2 - In addition to the Golf, VW has the TDI in the Jetta, Passat, Beetle, and Touareg. The Passat and Jetta offer a bit more interior room than the Mazda 3 Skyactiv (a great little car, in its own right). Audi offers the TDI in the A3 now, with more to come. BMW offers a remarkable turbodiesel in the X5 SUV … they had it in the 335d (one of my all time favorites), but stopped selling it after the 2011 model year. They’ll be bringing more …
Whoops … forgot about the Audi Q7 TDI. If I had gone to medical school, I’d be driving one of these …
We have owned a diesel car almost continuously since our first in 1981. For many years, diesel fuel and 87 octane gasoline regularly traded places for lowest price. Lately, meaning the past several years, diesel has consistently been more expensive than 87 octane excepting for a short time during later in 2011. Now, diesel is again more expensive than 87 octane and premium grade gasoline as well. I like my diesel car but will likely not buy another except possibly for the novelty of owning a diesel. Gasoline car fuel mileage is almost as good as a diesel now and diesels need special, expensive crankcase oil. VW diesels need more frequent, expensive fuel filter changes. Can’t speak for the others. Don’t expect to save significant money if you can save any at all with a diesel car. It used to be possible when diesel engines were simple but not now.
Do these diesel cars require urea injection into the exhaust to meet U.S. emissions standards? Another added cost, right?
The Jetta, Golf, Audi A3 and Beetle TDI don’t need urea injection. All others do, I think. But at least the ‘AdBlu’ urea is now available at some parts stores, like NAPA, for not too much money, unlike the huge $$$$ Mercedes charges.
Diesel taxes are a part of this, average 5 cents a gallon more, with some states more than 10 cents a gallon more in taxes:
http://www.api.org/Oil-and-Natural-Gas-Overview/Industry-Economics/~/media/A375B82CC4184656A093C6168A1DD08E.ashx
Thanks for all the comments! In response to MPGomatic, I don’t think the fluctuations with the seasons or different refining process explain why on average the price went from essentially the same as gas (average of all grades) to 9% higher than gas. Since it looks like the switchover to ultra low sulfur diesel occurred in the summer of 2006, that seems like it would probably be the likely excuse to start charging more for diesel (as Caddyman indicated)
@bscar2 The skyactiv looks promising. I am interested in the options for gas cars with mpg about the same a diesel. I have been looking at the VW sportwagen. Its size would be more comparable to the CX5 and still gets a 20% improvement in highway mpg over the gas technology (42 vs 35 mpg).
Uncleturbo, do you know where to find the data for number of gallons sold of gas and diesel (demand) to support your statement that recently demand for diesel has be higher than projections? Also, I’m not sure that the actual amount of refined fuel reflects predicted demand, as the oil companies may want to produce less of diesel to keep the price artificially high?
@Bing Unfortunately, the diesel fuel data on the EIA site only goes back to 1994, so I am not sure if the price of diesel relative to gas has been rising since 1981. It did not seem to rise (again relative to gas) from 94 to 2006 though.
@docdan - Worldwide demand for diesel fuel - barring conspiracy theories about price manipulation by key players - is the most likely culprit. America is literally exporting boatloads of diesel fuel. This is running up the price at the pump. The world wants our diesel.
The seasonal fluctuation in price is what it is, and has been what it is, for eons. The world wants the fuel that our refineries are producing. Yet our refineries are not efficient producers of diesel fuel (the cracking issue).
The Keystone pipeline isn’t about creating lower prices at the pump for Americans. It’s about refining more fuel to be exported from this country. Yes, it will create some jobs. But it there’s more than a good chance that it won’t lower fuel prices. It will, from many reports, increase fuel prices in the Midwest, where there’s a currently glut of petroleum.
Here’s an article on NPR about US petroleum product exports …
http://www.npr.org/2011/12/29/144155269/gas-pains-u-s-diesel-gas-exports-surpass-imports
If we as a country fully embrace the boom in cheap Natural Gas, we will lower the use of Diesel Fuel/Heating Oil, by retrofitting trucks and adding more CNG buses, as well as swapping out furnaces and boilers.
If we go whole hog, this can have a significant impact. The questions then, are: 1) what will we do with all of the “excess” diesel, and 2) will it have an effect on prices at the pump.
@docdan, my statement is based on general reading and I don’t have time to find references for support. If you believe that price at the pump reflects the general economic “supply and demand determines price” principals then the current price of diesel in the US reflects higher demand than available supplies. Supply of fuels is complicated as refineries are set up to produce a mix of fuels and cannot refine gasoline and diesel at the same time. Refinery capacity is also affected by outside factors such as weather, breakdown of old equipment, fire, and lack of crude to refine. Europe has a much higher number of diesel cars on the road and much greater % of the fleet of cars are diesel vs gas. Therefore Europes refineries produce more diesel products vs gasoline compared to US refineries.
I have read that there is an actual plan to start building over-the-road heavy trucks to operate on LNG…Interstate truck stops would be equipped to provide this fuel which today costs a fraction of what diesel fuel sells for…Railroad locomotives might also be able to utilize this low-cost fuel…
I know that many former landfill sites produce enough methane (basically natural gas) to support large diesel powered generators that produce commercial power…Advanced diesel technology allows 90% of the fuel consumed to be methane. A small amount of diesel is still injected to “light the fire”, the methane allowed to flow in with the air…
“I would like to get a new car with better gas mileage, so I am considering a diesel engine.” A diesel engine has zero gas mileage, you need to look at a different car, maybe one that uses gasoline.
BTW You might want to add that a lot of diesel is used by the farmers at spring planting and harvesting. It depends on your local crops.
Maybe the market is recognizing the fact that diesel contains about 10% more energy/gallon than gasoline? We always talk about how ethanol (E85) needs to cost less than gas because it has 1/3 less energy per gallon. By that logic, diesel should cost more.
Since Katrina the price of diesel is on average 8.7% higher than gas.
For some reason when gas prices start to fluctuate…diesel prices rise at a much faster rate. When gas prices settle down…Diesel prices settle down to lower then high-octane. Before Christmas Diesel was selling around here at the same price as the mid-grade gas.